The inaccuracy of prostate biopsy in detecting and characterising prostate cancer (PCa) has led to a widespread use of repeat biopsy (RB).
To summarise the most recent data regarding indication, techniques, and clinical implications of RB.
A search of Medline, PubMed, and Scopus identified articles published in the last 7 yr (2008–2014) addressing the role of RB in the PCa setting. Abstracts deemed relevant to the defined review question were screened, and the data were extracted, analysed, and summarised.
RB can be considered either in patients with persistent PCa suspicion after a first negative systematic biopsy or during active surveillance (AS), either to confirm patient enrolment or to monitor the natural progression of the disease. Indication and biopsy techniques differ according to each PCa scenario. Magnetic resonance imaging (MRI)-guided RB has been gaining popularity because of its accuracy in detecting and characterising PCa. Indications for multiple RBs (eg, AS setting) should be carefully evaluated because of the cumulative risk of complications, especially infection. In the next few years, clinical and genetic markers are expected to further improve the ability to determine the need for RB.
RB indications and techniques in persistent PCa suspicion and AS should take into account the evolving field of imaging, management options, and the risk of possible complications. In an RB setting, the introduction in daily clinical practice of MRI-guided targeted biopsy has improved the accuracy in detecting PCa without significantly increasing the risk of finding indolent, low-risk PCa. Referral to specialised care centres should be considered in patients with persistent PCa suspicion to provide the most rationalised management in terms of indication, biopsy technique, complications, pathologic assessment, and, finally, clinical implications of the findings.
A man may require a second prostatic biopsy for a number of reasons. In the current report, we describe why, when, and how a patient should undergo rebiopsy of the prostate.
Keywords: Prostate cancer, Biopsy, Repeat biopsy, Rebiopsy, Active surveillance, Complications.
Repeat biopsy (RB) is usually contemplated in a prostate cancer (PCa) setting in two different clinical scenarios: (1) patients with persistent PCa suspicion after a first negative systematic biopsy and (2) during active surveillance (AS), either to confirm patient enrolment or to monitor the natural progression the disease during the follow-up period. Although some of the characteristics and technical aspects may be similar in these two circumstances, the rationale behind the choice of performing an RB and the clinical implications of the results differ substantially between the two settings.
The motivation behind performing an RB in men with a persistent suspicion of PCa after a negative biopsy is mainly related to the diagnostic uncertainty of the standard transrectal ultrasound (TRUS)-guided biopsy in detecting and characterising the cancer. The standard biopsy strategy is, indeed, subject to sampling error (25–35% and 10–20% for all and significant cancers, respectively) , , , and  and provides poor localisation of the disease. More specifically, the primary limitations of initial biopsy include the failure to accurately detect high-grade cancer, imprecise tumour risk stratification, and the detection of small, low-risk, indolent cancers , , , and .
In potential candidates for AS protocols, RB has been proposed to confirm patients’ eligibility or, during the follow-up, to eventually switch the patient to a definitive treatment in case of reclassification. In this scenario, RB is used to better classify tumour characteristics or for the early detection of tumour progression , , , and .
In the current review, we aim to summarise the most recent data regarding indication, techniques, and clinical implications of an RB in these circumstances.
2. Evidence acquisition
An initial search was carried out using the Medline, PubMed, and Scopus databases. Because of dramatic stage migrations over the last decades resulting from the introduction of prostate-specific antigen (PSA) screening, AS and, MRI, we mainly focussed on publications in the years 2008–2014 to provide data that may be applicable to contemporary PCa patients. However, we did not exclude commonly referenced and highly regarded older publications. The search terms used were (repeat biopsy OR saturation OR rebiopsy) AND (prostate OR prostate cancer) AND (diagnosis OR active surveillance OR radiotherapy OR focal therapy OR PSA failure OR PSA relapse). Abstracts were reviewed for relevance to the defined review question. If it was not clear from the abstract whether the paper might contain relevant data, the full paper was assessed. The references cited in all full-text articles were also assessed for additional relevant articles. Non-English articles were excluded from analysis. Relevant studies were then screened by the three authors, and data were extracted, analysed, and summarised. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses flowchart was used to report the number of papers identified and included or excluded at each stage (Fig. 1).
3. Evidence synthesis
3.1. Repeat biopsy after a negative first biopsy
3.1.1. Indication for repeating a prostate biopsy
The most frequent motivation behind an RB is to correct or mitigate previous undersampling or any error associated with previous biopsies. According to international guidelines (Table 1), several aspects should be considered to evaluate the risk of PCa after a first negative systematic biopsy , , , and . A rising and/or persistently elevated PSA level remains the most common indication to perform an RB. The presence, at first biopsy, of an atypical small acinar proliferation (ASAP) or multifocal prostatic intra-epithelial neoplasia (HGPIN) is widely considered an indication for RB at 6–12 mo after initial sampling . In a PSA screening scenario, the risk of having PCa 4 yr after an initially negative screen is <4%. In this case, the indication for RB should be evaluated according to patient age, PSA level, digital rectal examination (DRE), family history, and prostate volume . Finally, in the most recent guidelines, the use of additional biomarkers has been suggested to improve specificity in the RB setting (Table 1). Specifically, free-to-total PSA ratio (%fPSA), PSA density, and PSA velocity have been proposed to be helpful markers in the decision of when to perform an RB , , , and . Related to this, studies have shown that the prostate cancer antigen 3 (PCA3) score and Prostate Health Index (PHI) may improve the accuracy of PSA value and %fPSA in predicting the presence of PCa at RB , , , and . Moreover, several statistical tools have been developed to predict the risk of PCa after an initial negative biopsy. Moussa et al included several variables (age, PSA value, PSA kinetics, family history, ASAP, HGPIN, DRE, months from previous negative biopsy session, and number of previous negative cores) in a nomogram, which yielded an accuracy of 72% in predicting PCa at RB . Similarly, Rochester et al developed a model including age, PSA value, PSA velocity, %fPSA, prostate volume, and DRE. This risk model had an accuracy of 82% in predicting the outcome, allowing for a 39% reduction in the need for RB, although the model underperformed in the validation model (area under the curve: 70%) . Finally, a nomogram including %fPSA, previous HGPIN, DRE, PSA value, and PSA kinetics achieved an overall accuracy of 86% in predicting the presence of PCa at RB .
|Topic||European Association of Urology  and ||American Urological Association ||National Comprehensive Cancer Network ||National Institute for Health and Care Excellence guidelines |
|RB after a negative first biopsy||Indications are:|
• Rising and/or persistently elevated PSA levels
• Suspicious DRE, 5-30% risk of cancer;
• ASAP, 40% risk of cancer;
• Extensive (multiple biopsy sites) prostatic intra-epithelial neoplasia, 20-30% risk of cancer.
|Saturation biopsy, taking tissue from >20 locations, may be considered in men with persistently elevated PSA levels and multiple previous negative prostate biopsy specimens.||For men with multiple previous negative biopsy specimens, a saturation biopsy may be considered. Stratification of risk and use of biomarkers that improve specificity such as PCA3 or %fPSA.|
Multiparametric MR plays an increasing role in the evaluation for RB.
|Consider multiparametric MRI (using T2-imaging and DWI) for men with a negative TRUS 10–12 core biopsy to determine whether another biopsy is needed.|
Do not offer another biopsy if the multiparametric MRI (using T2-imaging and DWI) is negative, unless any of the risk factors listed are present:
• Abnormal DRE findings.
|RB in active surveillance protocols||AS is based on repeated DRE, PSA testing, and, most importantly, RBs. Early repeated confirmatory biopsies have become an important part of the selection process and are based on the risk of underdetection of grade 4 at the initial biopsy||An ideal regimen for AS has not been defined but could include periodic physical examination and PSA testing or periodic RB to assess for sampling error of the initial biopsy as well as for subsequent progression of tumour grade and/or volume.||Needle biopsy of the prostate should be repeated within 6 mo of diagnosis if initial biopsy obtained <10 cores or was assessment discordant.|
An RB should be considered if prostate exam changes or PSA level increases, but neither parameter is very reliable for detecting PCa progression.
An RB should be considered as often as annually to assess for disease progression, because PSA kinetics may not be as reliable as monitoring parameters to determine progression of disease.
RBs are not indicated when life expectancy is <10 yr or appropriate when men are on observation.
|At 1 yr after AS enrolment. If there is concern regarding clinical or PSA changes at any time during AS, reassess with multiparametric MRI and/or RB.|
%fPSA = free-to-total PSA ratio; AS = active surveillance; ASAP = atypical small acinar proliferation; DRE = digital rectal examination; DWI = diffusion-weighted imaging; HGPIN = high-grade prostatic intra-epithelial neoplasia; MR = magnetic resonance; MRI = magnetic resonance imaging; PCA3 = prostate cancer antigen 3; PSA = prostatic-specific antigen; RB = repeated biopsy; RT = radiotherapy; TRUS = transrectal ultrasound.
Last, it has been suggested that the addition of genetic markers to current clinical parameters may improve PCa risk prediction as well . For instance, hypermethylation of genes such as glutathione-S-transferase P1 (GSTP1) and adenomatous polyposis coli (APC) has been suggested as a potential indicator of the need to perform an RB . The improvement obtained with all these clinical and genetic markers is actually modest but may be beneficial for better determining the need for RB  and .
In this context, one controversial topic is related to the number of procedures (number of biopsy sessions) that patients should undergo to exclude PCa presence. Often, multiple biopsy sessions are a direct consequence of the inadequacy of the performed biopsy . Although PCa detection is inversely related to the number of biopsy sessions performed , PCa can be found at each round of sampling . However, as reported, for instance, by Stav et al, virtually all tumours detected after a series of three negative biopsies are of low volume and indicated well-differentiated disease, even in patients with a persistently high suspicion of cancer (PSA value >10 ng/ml; PSA velocity >0.75 ng/ml per year, and %fPSA <0.2) . Since biopsy repetition increases the risk of overdiagnosis due to the detection of low-grade PCa  and , early consideration of MRI-guided, targeted RB and the referral to specialised care centres is warranted.
3.1.2. Transrectal ultrasound-guided versus transperineal template versus magnetic resonance imaging-guided biopsy
The false-negative rate of transrectal systematic biopsy may be as high as 47%  (Table 2). Traditionally, transrectal systematic biopsy has been the most widely used technique due to its user friendliness. Transperineal template biopsy has the benefit of potentially detecting additional PCa, especially in the anterior zone of the prostate  and , but it may require general anaesthesia with a potential increased risk of morbidity. MRI-guided biopsy has been gaining popularity due to its accuracy in detecting and characterising intermediate and high-grade PCa . In a recent meta-analysis, Nelson et al compared the cancer detection rate between TRUS versus transperineal versus MRI-guided biopsy. Their study included 46 studies with a total of 4657 patients . Cancer detection rates were estimated to be 28% (95% CI, 22–34%), 37% (95% CI, 31–42%), and 37% (95% CI, 30–43%) for transrectal, transperineal, and MRI-guided biopsy, respectively. After taking into account the study variances, the cancer detection rates were calculated to be 30%, 37%, and 38% for transrectal, transperineal, and MRI-guided biopsy, respectively (p = 0.06 [transperineal vs transrectal biopsy] and p = 0.03 [MRI-guided vs transrectal biopsy] . Notably, MRI-guided biopsy required the fewest biopsy cores to achieve the greatest cancer detection rate .
|Authors||Year||Patients included, no.||Cores taken, no.†||Saturation sampling||Targeted sampling||Approach, Guidance||CDR, %||AS|
|Active treatment delivered, %|
|After negative first biopsy|
|Abdollah et al ||2011||140||24||Yes||No||TR, TRUS||31||–||–|
|Scattoni et al ||2011||340||24||Yes||No||TR, TRUS||28||–||–|
|Zaytoun et al ||2011||663|
|20.7, 20 (20–24)|
12.3, 12 (12–14)
|Taira et al ||2010||294||25.7||Yes||No||TR, TRUS||47||–||–|
|Shimbo et al ||2009||77||14||No||No||TR, TRUS||35||–||–|
|Rochester et al ||2009||110||>10, NA (NA)||No||No||TR, TRUS||31||–||–|
|Stav et al ||2008||27||62, NA (41–76)||Yes||No||TR, TRUS||11‡||–||–|
|Yuasa et al ||2008||127||8, NA (NA)||No||No||TR, TRUS||18||–||–|
|Leite et al ||2008||76||12, NA (NA)||No||No||TR, TRUS||8||–||–|
|Benecchi et al ||2008||419||12, NA (12–24)||No||No||TR, TRUS||31||–||–|
|Tan et al ||2008||142||NA, 20 (NA)||Mixed||No||TR, TRUS||23||–||–|
|Haese et al ||2008||463||12, 16 (10–NA)||No||No||TR, TRUS||28||–||–|
|Simon et al ||2008||40||64, NA (39–139)||Yes||No||TR, TRUS||45||–||–|
|Ekwueme et al ||2013||270||28, NA (16–43)||Yes||No||TP, TRUS||55||–||–|
|Abdollah et al ||2011||140||24||Yes||No||TP, TRUS||26||–||–|
|Dimmen et al ||2011||69||19.9||Yes||No||TP, TRUS||55||–||–|
|Pal et al ||2011||40||36||Yes||No||TP, TRUS||40||–||–|
|Novara et al ||2010||143||24||Yes||No||TP, TRUS||26||–||–|
|Sonn et al ||2014||105||15, NA (NA)||No||Yes||TR, MRI||34||–||–|
|Roethke et al ||2012||100||4||No||Yes||TR, MRI||52||–||–|
|Hadaschik et al ||2011||49||23.7||Yes||No||TR, MRI||45||–||–|
|Franiel et al ||2011||54||4||No||Yes||TR, MRI||39||–||–|
|Hambrock et al ||2010||68||4||No||Yes||TR, MRI||59||–||–|
|Sciarra et al ||2010||90||NA||No||Yes||TR, MRI||49||–||–|
|Testa et al ||2010||54||NA||No||Yes||TR, MRI||41||–||–|
|AS: confirmatory biopsy|
|Hu et al ||2014||113||NA, 13 (NA)||No||Yes||TR, MRI||76||37||NA|
|King et al ||2013||52||12, 12 (12–12)||No||No||TR, TRUS||44||17||17|
|Motamedinia et al ||2012||60||17, NA (6–32)||No||No||TR, TRUS||55||32||17|
|Barzell et al ||2012||124||9.5, 10 (NA)|
90, 89.7 (NA)
|Abouassaly et al ||2008||52||20, NA (NA)||Yes||No||TR, TRUS||NA||38||NA|
|Berglund et al ||2008||104||NA, 14 (NA)||No||No||TR, TRUS||74||27||20|
|Welty et al ||2014||685||NA, 13 (11–16)||No||No||TR, TRUS||–||NA||43|
|Barayan et al ||2014||300||NA, NA (6–16)||No||No||TR, TRUS||–||32||20|
|Bul et al ||2012||757||NA, NA (8–12)||No||No||TR, TRUS||–||22||NA|
|Porten et al ||2011||377||NA||No||No||TR, TRUS||–||34||20|
|Kotb et al ||2011||102||NA||No||No||TR, TRUS||–||10-31||NA|
|Whitson et al ||2011||241||NA||No||No||TR, TRUS||–||23||NA|
|San Francisco et al ||2011||120||20, 20 (20–20)||No||No||TR, TRUS||–||30||NA|
|Tseng et al ||2010||45||NA, NA (12–14)||No||No||TR, TRUS||–||NA||NA|
|Adamy et al ||2011||238||NA||No||No||TR, TRUS||–||26||NA|
|Ross et al ||2010||290||NA||No||No||TR, TRUS||–||35||35|
|Al Otaibi et al ||2008||186||7, 8 (6–16)||No||No||TR, TRUS||–||36||31|
* Data are further stratified according to the clinical scenario.
† Where three values given, data are given as mean, median (range).
‡ After three previous negative biopsies.
CDR = cancer detection rate; MRI = magnetic resonance imaging; NA = not available; RB = repeat biopsy; TP = transperineal; TR = transrectal; TRUS = transrectal ultrasound.
As anticipated in the above-cited meta-analysis  and recently confirmed by the most updated National Comprehensive Cancer Network guidelines, MRI will play an increasing role in evaluating the need to perform an RB . Sonn et al found a cancer detection rate (CDR) of 34% using MRI-guided fusion technology for RB, with 72% of detected PCas being clinically significant (Gleason 3 + 4 or Gleason 6 with maximal cancer core length >4 mm) . Moreover, MRI-guided RB identified significantly more clinically significant cancers relative to standard sextant biopsy (91% vs 54%).
In a series of 438 consecutive patients with an increased PSA level and at least one prior negative biopsy who underwent MRI, Hoeks et al reported a CDR of 41% using in-bore targeted biopsy, with 87% of these cancers found to be clinically significant (Gleason grade 4–5 or PSA level >10 ng/ml or PSA density >0.15 ng/ml per millilitre; Gleason grade 4-5 or stage pT3 or tumour volume >0.5 ml in case of prostatectomy) . In a similar cohort of 100 patients, Pepe et al reported a CDR of 40.7% with accuracy, sensitivity, specificity, and positive and negative predictive value of MRI in diagnosing Gleason 7–10 PCa of 81%, 100%, 79%, 56%, and 100%, respectively . Borkowetz et al reported a study cohort of 195 RB patients who underwent MRI-guided transperineal RB (with a mean of nine cores) and additionally underwent a systematic transrectal biopsy (mean of 12 cores) . The overall detection rate was 44% (85 of 195 patients) in targeted biopsy and 32% (62 of 195) in systematic biopsy (p = 0.002). Regarding Gleason score upgrading, 44% more Gleason 7–10 PCa were detected using additional targeted biopsy compared to systematic biopsy alone. Conversely, 12% more Gleason 7–10 cancers were found using systematic biopsy in addition to targeted biopsy, confirming the need to perform a traditional systematic biopsy in addition to the MRI-guided procedure .
3.1.3. Number and location of cores
Beyond the difficulties in identifying RB candidates, the second most challenging aspect is deciding the number and the location of the cores to be taken to maximise the accuracy of a second prostate sampling. Efforts to overcome sampling error include performing multiple RBs and increasing the core number, and have resulted in the overdetection of indolent cancers, morbidity attributed to unnecessary biopsies, and an increase in costs , , , and . Furthermore, increasing the number of cores beyond the extended systematic TRUS-guided biopsy usually results in a marginal increase in the overall detection rate and simply increases the rate of indolent cancer detection . The majority of the currently available guidelines suggest performing saturation biopsy for men with multiple, previous negative biopsies , , , and . Anterior and transitional zone sampling should be considered at RB, since it has been shown that up to 83% and 35% of patients who undergo a saturation RB harbour PCa in the anterior and transitional area, respectively , , and . Based on the findings that even initial extended biopsies (>12 cores) miss almost one-third of cancers or result in grade misclassification , a saturation approach has been suggested to improve PCa detection. For instance, Zaytoun et al compared the performance of saturation biopsy (n = 663; 20–24 cores) and extended biopsy (n = 393, 12–14 cores) after an initial negative biopsy . PCa was detected in 315 of the 1056 patients (29.8%), but saturation biopsy detected almost one-third more cancers (32.7% vs 24.9%; p = 0.007) with a slightly higher rate of insignificant cancers (40.1% vs 32.6%; Gleason sum 6 or three or fewer positive cores and a maximum of ≤50% of cancer in any positive core; p = 0.2) .
Increasing the number of cores is not sufficient to detect the cancer missed at first biopsy: The relationship between the number of biopsy cores taken and the resulting cancer detection rate is not linearly correlated . In fact, the curve tends to plateau, and the increase of cores taken in the template is not equivalent to the increase of detected cancer (Table 2). Interest has increased in defining more efficient biopsy schemes for PCa detection with the minimum number of cores. In a prospective evaluation of 340 consecutive patients who underwent a standardised 24-core RB after a first negative systematic biopsy, Scattoni et al attempted to identify the optimal combination of sampling sites (number and location) to detect PCa . They also showed that the ideal RB scheme varies according to the clinical characteristics of the patient. For instance, for patients with a previous ASAP diagnosis, the most advantageous scheme was a combination of a 14-core biopsy (without transitional area biopsies). For patients with no previous ASAP diagnosis and %fPSA ≤10%, the most advantageous scheme was a 14-core biopsy (including transitional area). Finally, the most advantageous sampling scheme for patients with no previous ASAP and %fPSA >10% was a saturation combination of a 20-core biopsy . These data confirm that cancer detection is influenced not only by the number of cores sampled but also by the exact location of the cores , , , and . Regarding MRI-guided targeted RB, two to four cores are usually taken from the suspicious area in addition to the systematic sextant biopsies. However, to date, the most informative number of cores that should be considered is still not well defined. In this context, MRI may have the potential role to select at RB those men who could advantageously undergo a targeted sampling only (eg, in the anterior area). For instance, Komai et al prospectively performed in 324 men a prebiopsy MRI followed by a combination of transrectal cores (n = 12) plus transperineal cores (n = 14). Significant cancers (defined as biopsy Gleason score ≥4 + 3 or ≥20% positive core or cancer length ≥5 mm) detected by the transperineal 14-core biopsy but not by the transrectal 12-core biopsy were frequent (≤92%) when MRI showed an anterior lesion sporadically (one case) among patients with a negative prebiopsy MRI .
In conclusion, the exact number and location of cores in an RB setting should be individualised according to patient and prostate characteristics. Saturation biopsy should be limited to selected cases, as it significantly increases the risk of overdiagnosis without substantial benefit for the patient. Although more, well-performed prospective studies are needed to validate the findings, the literature suggests that prebiopsy MRI and MRI-guided targeted biopsies may help determine which men and which specific prostate areas (eg, targeted only or anterior/transitional zones), respectively, should be undergo RB .
3.2. Repeat biopsy in active surveillance protocols
3.2.1. Confirmatory biopsy for enrolment
Roughly 30% of men diagnosed with PCa are considered to have low-risk disease and are potential candidates for AS protocols. However, 18–27% of those men with apparently low-risk cancer will be reclassified at RB into a higher risk category  and . Several institutions have reported risk factors for reclassification during AS, including initial biopsy characteristics, PSA velocity, PSA density, RB results, and other variables .
Confirmatory biopsy timing differs among centres. The first RB is usually recommended within 12 mo of the diagnostic biopsy, but, in many institutions, the confirmatory RB is performed immediately to confirm patient eligibility for AS. King et al reported on TRUS-guided, 12-core biopsy at an average time of 2.7 mo following diagnosis . Notably, 56% of patients demonstrated no evidence of PCa on RB. Overall, 14 of 23 men with a positive RB showed either an increase in cancer volume or an upgrade of Gleason score. Reclassification to intermediate or high risk was observed in 17% of the AS candidates . In a similar report, Motamedinia et al described a 31.7% reclassification at RB in 60 patients who were candidates for AS at initial biopsy . In the majority of these reports, the absence of cancer at immediate RB predicted a good prognosis with a lower risk of progression during AS .
Barzell et al compared the performance of the type of approach used (TRUS vs template transperineal biopsy) in 124 AS candidates who underwent a combined TRUS biopsy plus a template transperineal prostate mapping as a confirmatory strategy . Depending on the definition used, 8–22% versus 41–85% of men had PCa that was reclassified as intermediate or high risk at TRUS versus transperineal RB, respectively. Finally, the sensitivity of repeat TRUS biopsy to identify intermediate- to high-risk disease varied from 9% to 24% with the negative predictive value ranging from 23% to 60% .
Among men with cancer who are contemplating AS, MRI-targeted biopsy potentially improves risk stratification and reduces the need for RB . In a study of 388 consecutive patients with low-risk disease who underwent MRI-guided biopsy, Vargas et al reported that 20% were reclassified at confirmatory biopsy . Similarly, Hu et al  and Margel et al  found that by using MRI-guided biopsy, 36% and 32%, respectively, of the patients who were reclassified at confirmatory biopsy were no longer be suitable for AS (Table 2).
3.2.2. During follow-up
Various AS protocols using different numbers and locations of cores have been proposed. However, widely used surveillance schemes usually include at least a 12-core sampling from each sextant , , , and . Recent findings suggested that saturation and transperineal biopsies increase the progression to treatment in AS follow-up as a possible consequence of more adequate prostate sampling during AS follow-up  and , especially in the anterior area of the prostate. Specifically, it has been shown in men who underwent a transperineal template-guided mapping RB after two or more previous biopsies, that the cancer detection rate remained high, especially in the anterior-most aspects of the gland  and that the majority of AS patients treated with radical prostatectomy for disease progression showed significant (>1 cm) anterior zone PCa . This enhanced sampling may be associated with a beneficial early detection of significant disease but with an increased risk of overtreatment . For instance, Abouassaly et al reported the use of saturation RB at a median of 9 mo after AS enrolment . The disease of 38% of the patients was upstaged (defined as Gleason upgrading or increased disease volume), leading to a recommendation for active treatment. Patients with disease upstaging had significantly fewer cores taken at the initial diagnostic biopsy (11% with ≥20 cores vs 55% with <20 cores; p = 0.002), again highlighting the importance of initial biopsy adequacy . Other reports in the setting of RB during AS follow-up suggested that MRI might result in only a marginal increase in accuracy compared to systematic RB, because of the frequent presence of small, well-differentiated tumours .
Porten et al recently described a population of 377 AS patients in which 34% of men were found to have an increase in Gleason grade during follow-up . The majority of men who experienced an upgrade (81%) did so at the first RB, suggesting that men with low-grade, low-stage disease managed with AS who experience early upgrading are more likely to have experienced initial sampling error, whereas later upgrading may reflect tumour differentiation . Comparably, Al Otaibi and colleagues suggested that the result of the first RB appears to have a stronger impact on disease progression (5-yr progression-free survival was 82% vs 50% in positive vs negative first RB; p = 0.02) and should be considered for treatment delivery . Finally, in a recent cohort of 300 PCa patients included in an AS protocol, the risk of progression decreased from 20.9% to 8% and 0% on the second, third, and fourth RB, respectively , suggesting that patients who are likely to progress are usually detected in the first 2 yr following diagnosis. Moreover, the clinical features at baseline and during follow-up of an AS cohort have been demonstrated to be associated with short-term reclassification to higher risk at RB. For instance, Bul et al reported data taken from 757 patients included in the Prostate Cancer Research International Active Surveillance (PRIAS) protocol, of whom 163 (21.5%) were reclassified as not suitable for AS during the follow-up period . Analyses showed that reclassification to higher risk was significantly influenced by the number of initial positive cores (two vs one; odd ratio [OR]: 1.8; p = 0.002), higher PSA density (OR: 2.1; p = 0.003), and PSA DT <3 yr (OR: 1.7; p = 0.01). The outcome was not influenced by age, clinical stage, number of cores taken, or PSA levels . Similarly, Whitson et al confirmed that PSA fluctuations should be neglected during the first 24 mo of surveillance in men with well-staged, low-risk PCa, making RB the most accurate tool to assess previous misclassification and/or tumour progression .
3.3. General considerations
3.3.1. Repeat biopsy: Should the antibiotic prophylaxis be different?
A pathophysiology study confirmed that a small but statistically significant increase in chronic inflammation should be expected when patients undergo serial biopsies within an active surveillance protocol . Moreover, previous exposure to antibiotics puts a candidate for RB at a potential higher risk of infectious complications. A range of infectious complications may occur after prostate needle biopsy, including asymptomatic bacteriuria, urinary tract infection, and bacteremia accompanied by sepsis. In addition, studies have reported that 11–22% of men undergoing prostate needle biopsy harbour fluoroquinolone-resistant organisms within the rectum . Ehdaie et al showed that the risk of postbiopsy infection for a man who has undergone one or two previous biopsies is about 2% and then rises to 5%, 10%, and 15% for patients who have undergone three, four, and five or more biopsies, respectively . In light of an increasing prevalence of fluoroquinolone resistance, recent data suggest a tailored approach to prophylaxis , , and . In particular, it is suggested that screening for fluoroquinolone-resistant pathogens using a rectal swab culture prior to biopsy can direct antibiotic prophylaxis and significantly reduce infectious complications .
3.3.2. Rate of complications in the repeat-biopsy setting
Using the Surveillance Epidemiology and End Results (SEER)-Medicare database, Loeb et al identified 3640 men who underwent multiple biopsies and showed similar 30-d hospitalisation rates between RB patients and the randomly selected control population . They demonstrated that although each biopsy was associated with a significant risk of complications, the RB procedure itself was not associated with a greater risk of serious complications requiring hospital admission compared to the initial biopsy setting . Controversial results were observed in the Prostate, Lung Colorectal and Ovary (PLCO) trial, in which noninfection complications were less frequent in patients who underwent RB relative to naive patients (OR: 0.3; 95% CI, 0.1–0.9) . Finally, findings suggest that erectile function is not significantly affected by RB  and . Patients should be informed that temporary erectile dysfunction may be present after RB, especially after a saturation procedure .
Although the risk of complications in the RB setting is low, it is mandatory to highlight that each subsequent biopsy increases the cumulative rate of complications for an individual patient. Indeed, some reports have suggested that the number of previous prostate biopsies is significantly associated with an increased risk of infectious complications. For instance, Ehdaie et al showed a 1.3-fold higher risk of infection for every previous biopsy (p = 0.04) in a cohort of 403 US patients .
The inadequacy of standard biopsy in detecting and characterising PCa has led to the increase of RBs in several urologic scenarios. RB indications and techniques in persistent PCa suspicion and AS should take the evolving field of imaging, as well as management options and the possible risk of complications, into careful consideration.
In an RB setting, the introduction to daily clinical practice of MRI-guided targeted biopsy has improved the accuracy in detecting PCa without significantly increasing the risk of finding indolent, low-risk PCa. In this context, given the limitations and the clinical difficulties depicted in the current review, it appears essential to refer patients who may be candidates for RB to specialised centres. A dedicated, multidisciplinary team of urologists, radiologists, and pathologists can provide the most rationalised management in terms of clinical indication, biopsy techniques, complications, pathologic assessment, and, finally, clinical implications of the findings. Additional insights regarding biopsy techniques, new imaging technology, and novel biological markers are desirable.
Author contributions: Umberto Capitanio had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Capitanio, Pfister, Emberton.
Acquisition of data: Capitanio, Pfister, Emberton.
Analysis and interpretation of data: Capitanio, Pfister, Emberton.
Drafting of the manuscript: Capitanio, Pfister, Emberton.
Critical revision of the manuscript for important intellectual content: Capitanio, Pfister, Emberton.
Statistical analysis: None.
Obtaining funding: None.
Administrative, technical, or material support: None.
Supervision: Capitanio, Pfister, Emberton.
Other (specify): None.
Financial disclosures: Umberto Capitanio certifies that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the subject matter or materials discussed in the manuscript (eg, employment/affiliation, grants or funding, consultancies, honoraria, stock ownership or options, expert testimony, royalties, or patents filed, received, or pending), are the following: None.
Funding/Support and role of the sponsor: None.
-  A. Heidenreich, P.J. Bastian, J. Bellmunt, et al. EAU guidelines on prostate cancer. Part 1: screening, diagnosis, and local treatment with curative intent—update 2013. Eur Urol. 2014;65:124-137 Crossref
-  H.B. Carter. American Urological Association (AUA) guideline on prostate cancer detection: process and rationale. BJU Int. 2013;112:543-547 Crossref
-  NCCN Clinical Practice Guidelines in Oncology. National Comprehensive Cancer Network Web site. http://www.nccn.org/professionals/physician_gls/f_guidelines.asp.
-  Prostate cancer: diagnosis and treatment. National Institute for Health and Care Excellence Web site. https://www.nice.org.uk/guidance/cg175. Accessed February 2015.
-  P.B. Singh, C.M. Nicholson, N. Ragavan, R.A. Blades, F.L. Martin, S.S. Matanhelia. Risk of prostate cancer after detection of isolated high-grade prostatic intraepithelial neoplasia (HGPIN) on extended core needle biopsy: a UK hospital experience. BMC Urol. 2009;9:3 Crossref
-  M.J. Roobol, X. Zhu, F.H. Schroder, et al. A calculator for prostate cancer risk 4 years after an initially negative screen: findings from ERSPC Rotterdam. Eur Urol. 2013;63:627-633 Crossref
-  F.K. Chun, A. de la Taille, H. van Poppel, et al. Prostate cancer gene 3 (PCA3): development and internal validation of a novel biopsy nomogram. Eur Urol. 2009;56:659-667
-  E.D. Crawford, K.O. Rove, E.J. Trabulsi, et al. Diagnostic performance of PCA3 to detect prostate cancer in men with increased prostate specific antigen: a prospective study of 1,962 cases. J Urol. 2012;188:1726-1731 Crossref
-  M. Lazzeri, A. Briganti, V. Scattoni, et al. Serum index test %[-2]proPSA and Prostate Health Index are more accurate than prostate specific antigen and %fPSA in predicting a positive repeat prostate biopsy. J Urol. 2012;188:1137-1143 Crossref
-  V. Scattoni, M. Lazzeri, G. Lughezzani, et al. Head-to-head comparison of prostate health index and urinary PCA3 for predicting cancer at initial or repeat biopsy. J Urol. 2013;190:496-501 Crossref
-  A.S. Moussa, J.S. Jones, C. Yu, K. Fareed, M.W. Kattan. Development and validation of a nomogram for predicting a positive repeat prostate biopsy in patients with a previous negative biopsy session in the era of extended prostate sampling. BJU Int. 2010;106:1309-1314 Crossref
-  M.A. Rochester, N. Pashayan, F. Matthews, A. Doble, J. McLoughlin. Development and validation of risk score for predicting positive repeat prostate biopsy in patients with a previous negative biopsy in a UK population. BMC Urol. 2009;9:7 Crossref
-  L. Benecchi, A.M. Pieri, M. Melissari, M. Potenzoni, C.D. Pastizzaro. A novel nomogram to predict the probability of prostate cancer on repeat biopsy. J Urol. 2008;180:146-149 Crossref
-  A.K. Kader, J. Sun, B.H. Reck, et al. Potential impact of adding genetic markers to clinical parameters in predicting prostate biopsy outcomes in men following an initial negative biopsy: findings from the REDUCE trial. Eur Urol. 2012;62:953-961 Crossref
-  B.J. Trock, M.J. Brotzman, L.A. Mangold, et al. Evaluation of GSTP1 and APC methylation as indicators for repeat biopsy in a high-risk cohort of men with negative initial prostate biopsies. BJU Int. 2012;110:56-62 Crossref
-  P.H. Gann, A. Fought, R. Deaton, W.J. Catalona, E. Vonesh. Risk factors for prostate cancer detection after a negative biopsy: a novel multivariable longitudinal approach. J Clin Oncol. 2010;28:1714-1720 Crossref
-  N.E. Abraham, N. Mendhiratta, S.S. Taneja. Patterns of repeat prostate biopsy utilization in contemporary clinical practice. J Urol. 2015;193:1178-1184 Crossref
-  K. Stav, D. Leibovici, J. Sandbank, A. Lindner, A. Zisman. Saturation prostate biopsy in high risk patients after multiple previous negative biopsies. Urology. 2008;71:399-403 Crossref
-  Eggener S. Commentary on “Is repeat prostate biopsy associated with a greater risk of hospitalization? Data from SEER-Medicare.” Loeb S, Carter HB, Berndt SI, Ricker W, Schaeffer EM, Department of Urology, New York University, New York, NY. J Urol 2013;189:867–70. [Epub 2012 Oct 9]. doi:10.1016/j.juro.2012.10.005. Urol Oncol 2014;32:935–6.
-  M. Park, D. You, J.H. Yoon, et al. Does repeat biopsy affect the prognosis of patients with prostate cancer treated with radical prostatectomy?. Analysis by the number of cores taken at initial biopsy. BJU Int. 2012;109:1474-1479 Crossref
-  A.V. Taira, G.S. Merrick, R.W. Galbreath, et al. Performance of transperineal template-guided mapping biopsy in detecting prostate cancer in the initial and repeat biopsy setting. Prostate Cancer Prostatic Dis. 2010;13:71-77 Crossref
-  K. Ekwueme, H. Simpson, H. Zakhour, N.J. Parr. Transperineal template-guided saturation biopsy using a modified technique: outcome of 270 cases requiring repeat prostate biopsy. BJU Int. 2013;111:E365-E373 Crossref
-  N. Lawrentschuk, N. Fleshner. The role of magnetic resonance imaging in targeting prostate cancer in patients with previous negative biopsies and elevated prostate-specific antigen levels. BJU Int. 2009;103:730-733 Crossref
-  A.W. Nelson, R.C. Harvey, R.A. Parker, C. Kastner, A. Doble, V.J. Gnanapragasam. Repeat prostate biopsy strategies after initial negative biopsy: meta-regression comparing cancer detection of transperineal, transrectal saturation and MRI guided biopsy. PloS One. 2013;8:e57480 Crossref
-  G.A. Sonn, E. Chang, S. Natarajan, et al. Value of targeted prostate biopsy using magnetic resonance-ultrasound fusion in men with prior negative biopsy and elevated prostate-specific antigen. Eur Urol. 2014;65:809-815 Crossref
-  P. Pepe, A. Garufi, G. Priolo, M. Pennisi. Can 3-tesla pelvic phased-array multiparametric MRI avoid unnecessary repeat prostate biopsy in patients with PSA <10 ng/mL?. Clin Genitourin Cancer. 2015;13:e27-e30 Crossref
-  Borkowetz A, Platzek I, Toma M, et al. Comparison of systematic transrectal biopsy to transperineal MRI/ultrasound-fusion biopsy for the diagnosis of prostate cancer. BJU Int. In press. doi:10.1111/bju.13023
-  V. Scattoni, M. Raber, U. Capitanio, et al. The optimal rebiopsy prostatic scheme depends on patient clinical characteristics: results of a recursive partitioning analysis based on a 24-core systematic scheme. Eur Urol. 2011;60:834-841 Crossref
-  Seles M, Gutschi T, Mayrhofer K, et al. Sampling of the anterior apical region results in increased cancer detection and upgrading in transrectal repeat saturation biopsy of the prostate. BJU Int. In press. doi:10.1111/bju.13108
-  N.J. Mabjeesh, G. Lidawi, J. Chen, L. German, H. Matzkin. High detection rate of significant prostate tumours in anterior zones using transperineal ultrasound-guided template saturation biopsy. BJU Int. 2012;110:993-997 Crossref
-  U. Capitanio, P.I. Karakiewicz, L. Valiquette, et al. Biopsy core number represents one of foremost predictors of clinically significant gleason sum upgrading in patients with low-risk prostate cancer. Urology. 2009;73:1087-1091 Crossref
-  O.M. Zaytoun, A.S. Moussa, T. Gao, K. Fareed, J.S. Jones. Office based transrectal saturation biopsy improves prostate cancer detection compared to extended biopsy in the repeat biopsy population. J Urol. 2011;186:850-854 Crossref
-  C. Maccagnano, A. Gallina, M. Roscigno, et al. Prostate saturation biopsy following a first negative biopsy: state of the art. Urol Int. 2012;89:126-135 Crossref
-  H.B. Carter, P.C. Albertsen, M.J. Barry, et al. Early detection of prostate cancer: AUA Guideline. J Urol. 2013;190:419-426 Crossref
-  Y. Komai, N. Numao, S. Yoshida, et al. High diagnostic ability of multiparametric magnetic resonance imaging to detect anterior prostate cancer missed by transrectal 12-core biopsy. J Urol. 2013;190:867-873 Crossref
-  C.J. Welty, J.E. Cowan, H. Nguyen, et al. Extended follow-up and risk factors for disease reclassification from a large active surveillance cohort for localized prostate cancer. J Urol. 2015;193:807-811 Crossref
-  R.K. Berglund, T.A. Masterson, K.C. Vora, S.E. Eggener, J.A. Eastham, B.D. Guillonneau. Pathological upgrading and up staging with immediate repeat biopsy in patients eligible for active surveillance. J Urol. 2008;180:1964-1967 discussion 1967–8
-  A.C. King, A. Livermore, T.A. Laurila, W. Huang, D.F. Jarrard. Impact of immediate TRUS rebiopsy in a patient cohort considering active surveillance for favorable risk prostate cancer. Urol Oncol. 2013;31:739-743 Crossref
-  P. Motamedinia, J.L. RiChard, J.M. McKiernan, G.J. DeCastro, M.C. Benson. Role of immediate confirmatory prostate biopsy to ensure accurate eligibility for active surveillance. Urology. 2012;80:1070-1074 Crossref
-  W.E. Barzell, M.R. Melamed, P. Cathcart, C.M. Moore, H.U. Ahmed, M. Emberton. Identifying candidates for active surveillance: an evaluation of the repeat biopsy strategy for men with favorable risk prostate cancer. J Urol. 2012;188:762-767
-  M.A. Bjurlin, J.S. Wysock, S.S. Taneja. Optimization of prostate biopsy: review of technique and complications. Urol Clin North Am. 2014;41:299-313 Crossref
-  J.C. Hu, E. Chang, S. Natarajan, et al. Targeted prostate biopsy in select men for active surveillance: do the Epstein criteria still apply?. J Urol. 2014;192:385-390 Crossref
-  D. Margel, S.A. Yap, N. Lawrentschuk, et al. Impact of multiparametric endorectal coil prostate magnetic resonance imaging on disease reclassification among active surveillance candidates: a prospective cohort study. J Urol. 2012;187:1247-1252 Crossref
-  Thompson JE, Hayen A, Landau A, et al. Medium-term oncologic outcomes for extended versus saturation biopsy and transrectal versus transperineal biopsy in active surveillance for prostate cancer. BJU Int. In press. doi:10.1111/bju.12858
-  H. Vasarainen, K. Lahdensuo, R. Savolainen, M. Ruutu, K. Taari, A. Rannikko. Diffusion-weighted magnetic resonance imaging in prostate cancer patients on active surveillance one year after diagnosis and before repeat biopsy. Scand J Urol. 2013;47:456-461 Crossref
-  A.V. Taira, G.S. Merrick, A. Bennett, et al. Transperineal template-guided mapping biopsy as a staging procedure to select patients best suited for active surveillance. Am J Clin Oncol. 2013;36:116-120 Crossref
-  A.S. Duffield, T.K. Lee, H. Miyamoto, H.B. Carter, J.I. Epstein. Radical prostatectomy findings in patients in whom active surveillance of prostate cancer fails. J Urol. 2009;182:2274-2278
-  R. Abouassaly, B.R. Lane, J.S. Jones. Staging saturation biopsy in patients with prostate cancer on active surveillance protocol. Urology. 2008;71:573-577 Crossref
-  S.P. Porten, J.M. Whitson, J.E. Cowan, et al. Changes in prostate cancer grade on serial biopsy in men undergoing active surveillance. J Clin Oncol. 2011;29:2795-2800 Crossref
-  M. Al Otaibi, P. Ross, N. Fahmy, et al. Role of repeated biopsy of the prostate in predicting disease progression in patients with prostate cancer on active surveillance. Cancer. 2008;113:286-292 Crossref
-  G.A. Barayan, F. Brimo, L.R. Begin, et al. Factors influencing disease progression of prostate cancer under active surveillance: a McGill University Health Center cohort. BJU Int.. 2014;114:E99-E104 Crossref
-  M. Bul, R.C. van den Bergh, A. Rannikko, et al. Predictors of unfavourable repeat biopsy results in men participating in a prospective active surveillance program. Eur Urol. 2012;61:370-377 Crossref
-  J.M. Whitson, S.P. Porten, J.F. Hilton, et al. The relationship between prostate specific antigen change and biopsy progression in patients on active surveillance for prostate cancer. J Urol. 2011;185:1656-1660 Crossref
-  A.S. Glass, S.P. Porten, M. Bonham, et al. Active surveillance: does serial prostate biopsy increase histological inflammation?. Prostate Cancer Prostatic Dis. 2013;16:165-169
-  B. Ehdaie, E. Vertosick, M. Spaliviero, et al. The impact of repeat biopsies on infectious complications in men with prostate cancer on active surveillance. J Urol. 2014;191:660-664 Crossref
-  A.K. Taylor, T.R. Zembower, R.B. Nadler, et al. Targeted antimicrobial prophylaxis using rectal swab cultures in men undergoing transrectal ultrasound guided prostate biopsy is associated with reduced incidence of postoperative infectious complications and cost of care. J Urol. 2012;187:1275-1279 Crossref
-  S. Loeb, H.B. Carter, S.I. Berndt, W. Ricker, E.M. Schaeffer. Is repeat prostate biopsy associated with a greater risk of hospitalization? Data from SEER-Medicare. J Urol. 2013;189:867-870 Crossref
-  P.F. Pinsky, H.L. Parnes, G. Andriole. Mortality and complications after prostate biopsy in the Prostate, Lung, Colorectal and Ovarian Cancer Screening (PLCO) trial. BJU Int. 2014;113:254-259
-  K. Braun, Y. Ahallal, D.D. Sjoberg, et al. Effect of repeated prostate biopsies on erectile function in men on active surveillance for prostate cancer. J Urol. 2014;191:744-749 Crossref
-  P. Pepe, F. Pietropaolo, G. Dibenedetto, F. Aragona. Erectile function after repeat saturation prostate biopsy: our experience in 100 patients. Arch Ital Urol Androl. 2013;85:130-132 Crossref
-  C. Akbal, P. Turker, H.H. Tavukcu, F. Simsek, L. Turkeri. Erectile function in prostate cancer-free patients who underwent prostate saturation biopsy. Eur Urol. 2008;53:540-544
-  A. Heidenreich, P.J. Bastian, J. Bellmunt, et al. EAU guidelines on prostate cancer. Part II: Treatment of advanced, relapsing, and castration-resistant prostate cancer. Eur Urol. 2014;65:467-479
-  F. Abdollah, G. Novara, A. Briganti, et al. Trans-rectal versus trans-perineal saturation rebiopsy of the prostate: is there a difference in cancer detection rate?. Urology. 2011;77:921-925 Crossref
-  M. Shimbo, S. Tomioka, M. Sasaki, et al. PSA doubling time as a predictive factor on repeat biopsy for detection of prostate cancer. Jpn J Clin Oncol. 2009;39:727-731 Crossref
-  T. Yuasa, N. Tsuchiya, T. Kumazawa, et al. Characterization of prostate cancer detected at repeat biopsy. BMC Urol. 2008;8:14 Crossref
-  K.R. Leite, L.H. Camara-Lopes, J. Cury, M.F. Dall’oglio, A. Sanudo, M. Srougi. Prostate cancer detection at rebiopsy after an initial benign diagnosis: results using sextant extended prostate biopsy. Clinics. 2008;63:339-342
-  N. Tan, B.R. Lane, J. Li, A.S. Moussa, M. Soriano, J.S. Jones. Prostate cancers diagnosed at repeat biopsy are smaller and less likely to be high grade. J Urol. 2008;180:1325-1329 discussion 1329 Crossref
-  A. Haese, A. de la Taille, H. van Poppel, et al. Clinical utility of the PCA3 urine assay in European men scheduled for repeat biopsy. Eur Urol. 2008;54:1081-1088 Crossref
-  J. Simon, R. Kuefer, G. Bartsch Jr., B.G. Volkmer, R.E. Hautmann, H.W. Gottfried. Intensifying the saturation biopsy technique for detecting prostate cancer after previous negative biopsies: a step in the wrong direction. BJU Int. 2008;102:459-462 Crossref
-  M. Dimmen, L. Vlatkovic, K.H. Hole, J.M. Nesland, B. Brennhovd, K. Axcrona. Transperineal prostate biopsy detects significant cancer in patients with elevated prostate-specific antigen (PSA) levels and previous negative transrectal biopsies. BJU Int. 2012;110:E69-E75 Crossref
-  R.P. Pal, M. Elmussareh, M. Chanawani, M.A. Khan. The role of a standardized 36 core template-assisted transperineal prostate biopsy technique in patients with previously negative transrectal ultrasonography-guided prostate biopsies. BJU Int. 2012;109:367-371 Crossref
-  G. Novara, R. Boscolo-Berto, C. Lamon, et al. Detection rate and factors predictive the presence of prostate cancer in patients undergoing ultrasonography-guided transperineal saturation biopsies of the prostate. BJU Int. 2010;105:1242-1246 Crossref
-  M. Roethke, A.G. Anastasiadis, M. Lichy, et al. MRI-guided prostate biopsy detects clinically significant cancer: analysis of a cohort of 100 patients after previous negative TRUS biopsy. World J Urol. 2012;30:213-218 Crossref
-  B.A. Hadaschik, T.H. Kuru, C. Tulea, et al. A novel stereotactic prostate biopsy system integrating pre-interventional magnetic resonance imaging and live ultrasound fusion. J Urol. 2011;186:2214-2220 Crossref
-  T. Franiel, C. Stephan, A. Erbersdobler, et al. Areas suspicious for prostate cancer: MR-guided biopsy in patients with at least one transrectal US-guided biopsy with a negative finding—multiparametric MR imaging for detection and biopsy planning. Radiology. 2011;259:162-172 Crossref
-  T. Hambrock, D.M. Somford, C. Hoeks, et al. Magnetic resonance imaging guided prostate biopsy in men with repeat negative biopsies and increased prostate specific antigen. J Urol. 2010;183:520-527
-  A. Sciarra, V. Panebianco, M. Ciccariello, et al. Value of magnetic resonance spectroscopy imaging and dynamic contrast-enhanced imaging for detecting prostate cancer foci in men with prior negative biopsy. Clin Cancer Res. 2010;16:1875-1883 Crossref
-  C. Testa, R. Schiavina, R. Lodi, et al. Accuracy of MRI/MRSI-based transrectal ultrasound biopsy in peripheral and transition zones of the prostate gland in patients with prior negative biopsy. NMR Biomed. 2010;23:1017-1026 Crossref
-  A.F. Kotb, S. Tanguay, M.A. Luz, W. Kassouf, A.G. Aprikian. Relationship between initial PSA density with future PSA kinetics and repeat biopsies in men with prostate cancer on active surveillance. Prostate Cancer Prostatic Dis. 2011;14:53-57 Crossref
-  I.F. San Francisco, L. Werner, M.M. Regan, M.B. Garnick, G. Bubley, W.C. DeWolf. Risk stratification and validation of prostate specific antigen density as independent predictor of progression in men with low risk prostate cancer during active surveillance. J Urol. 2011;185:471-476 Crossref
-  K.S. Tseng, P. Landis, F. Brimo, A.W. Partin, J.I. Epstein, H.B. Carter. Repeat prostate biopsies predict location of index cancer in an active surveillance cohort. BJU Int. 2011;108:1415-1420 Crossref
-  A. Adamy, D.S. Yee, K. Matsushita, et al. Role of prostate specific antigen and immediate confirmatory biopsy in predicting progression during active surveillance for low risk prostate cancer. J Urol. 2011;185:477-482 Crossref
-  A.E. Ross, S. Loeb, P. Landis, et al. Prostate-specific antigen kinetics during follow-up are an unreliable trigger for intervention in a prostate cancer surveillance program. J Clin Oncol. 2010;28:2810-2816 Crossref
-  C.M. Hoeks, M.G. Schouten, J.G. Bomers, et al. Three-Tesla magnetic resonance-guided prostate biopsy in men with increased prostate-specific antigen and repeated, negative, random, systematic, transrectal ultrasound biopsies: detection of clinically significant prostate cancers. Eur Urol. 2012;62(5):902-909 10.1016/j.eururo.2012.01.047 Crossref
-  H.A. Vargas, O. Akin, A. Afaq, et al. Magnetic resonance imaging for predicting prostate biopsy findings in patients considered for active surveillance of clinically low risk prostate cancer. J Urol. 2012;188(5):1732-1738 10.1016/j.juro.2012.07.024 Crossref
a Department of Urology, Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
b Division of Experimental Oncology, URI, Urological Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
c Department of Urology, RWTH Aachen University, Aachen, Germany
d Division of Surgery and Interventional Science, University College London, London, UK
Corresponding author. Department of Urology, Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy. Tel. +39 02 2643 7286; Fax: +39 02 2643 7298.
© 2015 European Association of Urology, Published by Elsevier B.V.