Impact of increased number of biopsies on the nature of prostate cancer identified

Role of Systematic Biopsy in the Era of Targeted Biopsy: A Review

Prostate cancer (PCa) is a major public health issue, as the second most common cancer and the fifth leading cause of cancer-related deaths among men. Many PCa cases are indolent and pose minimal risk, making active surveillance a suitable management approach. However, clinically significant prostate carcinoma (csPCa) can lead to serious health issues, including progression, metastasis, and death. Differentiating between insignificant prostate cancer (inPCa) and csPCa is crucial for determining appropriate treatment. Diagnosis of PCa primarily involves trans-perineal and transrectal systematic biopsies. Systematic transrectal prostate biopsy, which typically collects 10-12 tissue samples, is a standard method, but it can miss csPCa and is associated with some complications. Recent advancements, such as magnetic resonance imaging (MRI)-targeted biopsies, have been suggested to improve risk stratification and reduce overtreatment of inPCa and undertreatment of csPCa, thereby enhancing patient quality of life and treatment outcomes. Guided biopsies are increasingly recommended for their ability to better detect high-risk cancers while reducing identification of low-risk cases. MRI-targeted biopsies, especially when used as an initial biopsy in biopsy-naïve patients and those under active surveillance, have become more common. Utilization of MRI-TB alone can decrease septic complications; however, the combining of targeted biopsies with perilesional sampling is recommended for optimal detection of csPCa. Future advancements in imaging and biopsy techniques, including AI-augmented lesion detection and robotic-assisted sampling, promise to further improve the accuracy and effectiveness of PCa detection.

Comparing 12-core and 20-core biopsy for prostate cancer diagnosis with transperineal MR/US fusion biopsy: assessing the effective number of systemic cores using propensity score matching

PURPOSE

For transperineal (TP) prostate biopsy, target biopsy for visible lesions on MRI is important, but there is no consensus of the number of systemic biopsy cores. Our study aimed to confirm the diagnostic efficiency of 20-core systemic biopsy by comparison with 12-core using propensity score matching (PSM).

METHODS

The 494 patients conducted the naive TP biopsy were retrospectively analyzed. There were 293 patients with 12-core biopsy and 201 patients with 20-core biopsy. PSM was performed for minimizing confounding variables, and the established effects' value was analyzed for 'index-positive or negative' clinically significant prostate cancer (csPCa) (Index means PIRADS Score ≥ 3 on multiparametric prostate MRI).

RESULTS

At 12-core biopsy, there were 126 cases of prostate cancer (43.0%), and 97 cases of csPCa (33.1%). At 20-core biopsy, there were 91 cases (45.3%) and 63 cases (31.3%). After propensity score matching, for index-negative csPCa, the estimated odds ratio was 4.03 (95% CI 1.35-12.09, p value 0.0128), and for index-positive csPCa, the estimated odds ratio was 0.98 (95% CI 0.63-1.52, p value 0.9308).

CONCLUSIONS

The 20-core biopsy did not show a higher detection rate for csPCa in comparison with the 12-core biopsy. However, when MRI did not show a suspicious lesion, 20-core biopsy showed higher odd ratio in comparison with 12-core biopsy. Therefore, if there is a suspicious lesion in MRI, 20-core biopsy is excessive and 12-core biopsy is sufficient. Whereas if there is no suspicious lesion in MRI, it is better to proceed with 20-core biopsy.

Prostate cancer diagnostic pathway: Is a one-stop cognitive MRI targeted biopsy service a realistic goal in everyday practice? A pilot cohort in a tertiary referral centre in the UK

OBJECTIVES

To evaluate the feasibility of a novel multiparametric MRI (mpMRI) and cognitive fusion transperineal targeted biopsy (MRTB) led prostate cancer (PCa) diagnostic service with regard to cancer detection and reducing time to diagnosis and treatment.

DESIGN

Consecutive men being investigated for possible PCa under the UK 2-week wait guidelines.

SETTING

Tertiary referral centre for PCa in the UK.

PARTICIPANTS

Men referred with a raised prostate-specific antigen (PSA) or abnormal digital rectal examination between February 2015 and March 2016 under the UK 2-week rule guideline.

INTERVENTIONS

An mpMRI was performed prior to patients attending clinic, on the same day. If required, MRTB was offered. Results were available within 48 hours and discussed at a specialist multidisciplinary team meeting. Patients returned for counselling within 7 days PRIMARY AND SECONDARY OUTCOME MEASURES: Outcome measures in this regard included the time to diagnosis and treatment of patients referred with a suspicion of PCa. Quality control outcome measures included clinically significant and total cancer detection rates.

RESULTS

112 men were referred to the service. 111 (99.1%) underwent mpMRI. Median PSA was 9.4 ng/mL (IQR 5.6-21.0). 87 patients had a target on mpMRI with 25 scoring Likert 3/5 for likelihood of disease, 26 4/5 and 36 5/5.57 (51%) patients received a local anaesthetic, Magnetic resonance imaging targeted biopsy (MRTB). Cancer was detected in 45 (79%). 43 (96%) had University College London definition 2 disease or greater. The times to diagnosis and treatment were a median of 8 and 20 days, respectively.

CONCLUSIONS

This approach greatly reduces the time to diagnosis and treatment. Detection rates of significant cancer are high. Similar services may be valuable to patients with a potential diagnosis of PCa.

Approaches for Initial Prostate Biopsy and Antibiotic Prophylaxis

CONTEXT

Debate on the optimal technique to use as an initial prostate biopsy (PB) strategy is continually evolving.

OBJECTIVE

To review recent advances and current recommendations regarding initial PB and antibiotic prophylaxis.

EVIDENCE ACQUISITION

A nonsystematic review of the literature was performed up to October 2014 using the PubMed and Embase databases. Articles were selected with preference for the highest level of evidence in publications within the past 5 yr.

EVIDENCE SYNTHESIS

The decision to perform PB is still based on an abnormal digital rectal examination or increased prostate0specific antigen (PSA) level without clear consensus about the absolute cutoff. Several biomarkers have been suggested to improve PSA-based PB decision-making and minimize overdiagnosis and overtreatment. The random 12-core transrectal (TR) ultrasound-guided approach remains the standard-of-care technique for PB. A >12-core scheme may be considered as an alternative in a single patient given his clinical features (large volume, low PSA levels). Transperineal biopsies may only be considered as an alternative to the TR route in special situations. Nevertheless, given the increase in antimicrobial resistance, the impact on the post-biopsy sepsis rate should be assessed in well-designed clinical trials. Imaging-guided targeted PB strategies, combined or not with random PBs, may represent the future of prostate cancer diagnosis by reducing the number of PBs and improving decision-making.

CONCLUSIONS

The 12-core TR scheme remains the standard of care for initial PB. The actual trend for PB strategy, with the aim of avoiding overdiagnosis of very low-risk cancers, could rapidly change our current indications and techniques through new biomarkers and imaging-guided targeted strategies. Nevertheless, the cost-benefit balance of these techniques should be closely assessed in the setting of initial PB strategy.

PATIENT SUMMARY

This review highlights current recommendations for prostate biopsy and possible advances in the near future.

Standards for prostate biopsy

PURPOSE OF REVIEW

A variety of techniques have emerged for the optimization of prostate biopsy. In this review, we summarize and critically discuss the most recent developments regarding the optimal systematic biopsy and sampling labeling along with multiparametric MRI and magnetic resonance-targeted biopsies.

RECENT FINDINGS

The use of 10-12-core-extended sampling protocols increases cancer detection rates compared with traditional sextant sampling and reduces the likelihood that patients will require a repeat biopsy, ultimately allowing more accurate risk stratification without increasing the likelihood of detecting insignificant cancers. As the number of cores increases above 12 cores, the increase in diagnostic yield becomes marginal. However, the limitations of this technique include undersampling, oversampling, and the need for repetitive biopsy. MRI and magnetic resonance-targeted biopsies have demonstrated superiority over systematic biopsies for the detection of clinically significant disease and representation of disease burden, while deploying fewer cores and may have applications in men undergoing initial or repeat biopsy and those with low-risk cancer on or considering active surveillance.

SUMMARY

A 12-core systematic biopsy that incorporates apical and far-lateral cores in the template distribution allows maximal cancer detection, avoidance of a repeat biopsy while minimizing the detection of insignificant prostate cancers. MRI-guided prostate biopsy has an evolving role in both initial and repeat prostate biopsy strategies, as well as active surveillance, potentially improving sampling efficiency, increasing the detection of clinically significant cancers, and reducing the detection of insignificant cancers.

Optimization of prostate biopsy: review of technique and complications

A 12-core systematic biopsy that incorporates apical and far-lateral cores in the template distribution allows maximal cancer detection and avoidance of a repeat biopsy while minimizing the detection of insignificant prostate cancers. Magnetic resonance imaging-guided prostate biopsy has an evolving role in both initial and repeat prostate biopsy strategies, potentially improving sampling efficiency, increasing the detection of clinically significant cancers, and reducing the detection of insignificant cancers. Hematuria, hematospermia, and rectal bleeding are common complications of prostate needle biopsy, but are generally self-limiting and well tolerated. All men should receive antimicrobial prophylaxis before biopsy.

Optimization of initial prostate biopsy in clinical practice: sampling, labeling and specimen processing

PURPOSE

An optimal prostate biopsy in clinical practice is based on a balance among adequate detection of clinically significant prostate cancers (sensitivity), assuredness regarding the accuracy of negative sampling (negative predictive value), limited detection of clinically insignificant cancers and good concordance with whole gland surgical pathology results to allow accurate risk stratification and disease localization for treatment selection. Inherent within this optimization is variation of the core number, location, labeling and processing for pathological evaluation. To date, there is no consensus in this regard. The purpose of this review is to 1) define the optimal number and location of biopsy cores during primary prostate biopsy among men with suspected prostate cancer, 2) define the optimal method of labeling prostate biopsy cores for pathological processing which will provide relevant and necessary clinical information for all potential clinical scenarios, and 3) determine the maximal number of prostate biopsy cores allowable within a specimen jar which would not preclude accurate histological evaluation of the tissue.

MATERIALS AND METHODS

A bibliographic search using PubMed® covering the period up to July 2012 yielded approximately 550 articles. Articles were reviewed and categorized based on which of the 3 objectives of this review was addressed. Data were extracted, analyzed and summarized. Recommendations are provided based on this literature review and our clinical experience.

RESULTS

The use of 10 to 12-core extended sampling protocols increases cancer detection rates compared to traditional sextant sampling methods and reduces the likelihood of repeat biopsy by increasing negative predictive value, ultimately allowing more accurate risk stratification without increasing the likelihood of detecting insignificant cancers. As the number of cores increases above 12, the increase in diagnostic yield becomes marginal. Only limited evidence supports the use of initial biopsy schemes involving more than 12 cores or saturation. Apical and laterally directed sampling of the peripheral zone increases cancer detection rate, reduces the need for repeat biopsies and predicts pathological features on prostatectomy while transition zone biopsies do not. There are little data to suggest that knowing the exact site of an individual positive biopsy core provides meaningful clinical information. However, determining laterality of cancer on biopsy may be helpful for predicting sites of extracapsular extension and therapeutic planning. Placement of multiple biopsy cores in a single container (greater than 2) appears to compromise pathological evaluation, which can reduce cancer detection rate and increase the likelihood of equivocal diagnoses.

CONCLUSIONS

A 12-core systematic biopsy that incorporates apical and far-lateral cores in the template distribution allows maximal cancer detection, avoids repeat biopsy, and provides information adequate for identifying men who need therapy and planning that therapy while minimizing the detection of occult, indolent prostate cancers. This literature review does not provide compelling evidence that individual site specific labeling of cores benefits clinical decision making regarding the management of prostate cancer. Based on the available literature, we recommend packaging no more than 2 cores in each jar to avoid reduction of the cancer detection rate through inadequate tissue sampling.

Detection rate of clinically insignificant prostate cancer increases with repeat prostate biopsies

To analyze if clinically insignificant prostate cancer (CIPC) is more frequently detected with repeat prostate biopsies, we retrospectively analyzed the records of 2146 men diagnosed with prostate cancer after one or more prostate biopsies. The patients were divided into five groups according to the number of prostate biopsies obtained, e.g. group 1 had one biopsy, group 2 had two biopsies and group 3 had three biopsies. Of the 2146 patients diagnosed with prostate cancer, 1956 (91.1%), 142 (6.6%), 38 (1.8%), 9 (0.4%) and 1 (0.1%) men were in groups 1, 2, 3, 4 and 5, respectively. Groups 4 and 5 were excluded because of the small sample sizes. The remaining three groups (groups 1, 2 and 3) were statistically analyzed. There were no differences in age or prostate-specific antigen level among the three groups. CIPC was detected in 201 (10.3%), 28 (19.7%) and 9 (23.7%) patients in groups 1, 2 and 3, respectively (P<0.001). A multivariate analysis showed that the number of biopsies was an independent predictor to detect CIPC (OR=2.688 for group 2; OR=4.723 for group 3). In conclusion, patients undergoing multiple prostate biopsies are more likely to be diagnosed with CIPC than those who only undergo one biopsy. However, the risk still exists that the patient could have clinically significant prostate cancer. Therefore, when counseling patients with regard to serial repeat biopsies, the possibility of prostate cancer overdiagnosis and overtreatment must be balanced with the continued risk of clinically significant disease.

Prospective evaluation of an extended 21-core biopsy scheme as initial prostate cancer diagnostic strategy

BACKGROUND

The debate on the optimal number of prostate biopsy core samples that should be taken as an initial strategy is open.

OBJECTIVE

To prospectively evaluate the diagnostic yield of a 21-core biopsy protocol as an initial strategy for prostate cancer (PCa) detection.

DESIGN, SETTING, AND PARTICIPANTS

During 10 yr, 2753 consecutive patients underwent a 21-core biopsy scheme for their first set of biopsy specimens.

INTERVENTION

All patients underwent a standardized 21-core protocol with cores mapped for location.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The PCa detection rate of each biopsy scheme (6, 12, or 21 cores) was compared using a McNemar test. Predictive factors of the diagnostic yield achieved by a 21-core scheme were studied using logistic regression analyses.

RESULTS AND LIMITATIONS

PCa detection rates using 6 sextant biopsies, 12 cores, and 21 cores were 32.5%, 40.4%, and 43.3%, respectively. The 12-core procedure improved the cancer detection rate by 19.4% (p=0.004), and the 21-biopsy scheme improved the rate by 6.7% overall (p<0.001). The six far lateral cores were the most efficient in terms of detection rate. The diagnostic yield of the 21-core protocol was >10% in prostates with volume >70 ml, in men with a prostate-specific antigen level<4 ng/ml, with a prostate-specific antigen density (PSAD) <0.20 ng/ml per gram. A PSAD <0.20 ng/ml per gram was the strongest independent predictive factor of the diagnostic yield offered by the 21-core scheme (p<0.001). The 21-core protocol significantly increased the rate of PCa eligible for active surveillance (62.5% vs 48.4%; p=0.036) than those detected by a 12-core scheme without statistically increasing the rate of insignificant PCa (p=0.503).

CONCLUSIONS

A 21-core biopsy scheme improves significantly the PCa detection rate compared with a 12-core protocol. We identified a cut-off PSAD (0.20 ng/ml per gram) below which an extended 21-core scheme might be systematically proposed to significantly improve the overall detection rate without increasing the rate of detected insignificant PCa.

The 20-core prostate biopsy as an initial strategy: impact on the detection of prostatic cancer

INTRODUCTION

To increase the detection rate of prostate cancer in recent years, we examined the increase in the number of cores taken at initial prostate biopsy. We hypothesized that an increasing number of cores may undermine the accuracy of models predicting the presence of prostate cancer at initial biopsy in patients submitted to 20-core initial biopsy.

METHODS

A total of 232 consecutive patients with prostate-specific antigen (PSA) between 4 and 20 ng/mL and/or abnormal digital rectal examination (DRE) underwent 12-core prostate biopsy protocol (group 1) or 20-core prostate biopsy protocol (group 2). The patients were divided into subgroups according to the results of their serum PSA and prostate volume. We evaluated the cancer detection rate overall and in each subgroup. Clinical data were analyzed using chi-square analysis and the unpaired t-test or 1-way ANOVA with significance considered at 0.05.

RESULTS

The 2 groups of patients were not significantly different with regard to parameters (age, abnormal DRE and serum PSA), although median prostate volume in group 1 (57.76 +/- 26.94 cc) were slighter greater than in group 2. Cancer detection rate for patients submitted to 20 prostate biopsy was higher than patients submitted to 12 prostate biopsy (35.2% vs. 25%, p = 0.095). Breakdown to PSA level showed a benefit to 20 prostate biopsy for PSA <6 ng/mL (37.1% vs. 12.9%, p = 0.005). Stratifying results by prostate volume, we found that the improvement of cancer detection rate with 20 prostate biopsy was significant in patients with a prostate volume greater than 60 cc (55% in 20 prostate biopsy vs. 11.3% p < 0.05). Morbidity rates were identical in groups 1 and 2 with no statistically significant difference. There appeared to be no greater risk of infection and bleeding with 20 prostate biopsy protocol.

CONCLUSION

The 20-core biopsy protocol was more efficient than the 12-core biopsy protocol, especially in patients with prostate specific antigen <6 ng/mL and prostate volume greater than 60 cc.

Prostate cancer detection after a negative prostate biopsy: lessons learnt in the Cleveland Clinic experience

Urologists are often faced with the dilemma of managing patients with a negative initial prostate biopsy in whom clinical or pathological risk for prostate cancer still exists. Such real-life challenging scenarios might raise questions such as: Who should undergo further biopsies? What are the optimal predictors for prostate cancer on subsequent biopsies? What is the optimal biopsy protocol that should be used? When to stop the biopsy cascade? The last decade has witnessed numerous studies that have analyzed factors conferring a significant risk for cancer discovered on repeat biopsies. We and others have developed predictive models to aid decision-making regarding pursuing further biopsies. For decades, high-grade prostatic intraepithelial neoplasia has been considered a strong risk indicator for subsequent cancer. However, it has been recently shown that only through segmentation of this heterogeneous population does the real risk profile emerge. Biopsy templates underwent modification regarding the number and location of cores with emergence of the transrectal or brachytherapy grid transperineal saturation biopsy. However, the best biopsy protocol remains controversial. We have refined the initial biopsy template to a 14 core initial biopsy template that optimizes cancer detection, and have shown that transrectal saturation biopsy significantly improves cancer detection for repeat biopsy. Another concern is the overdiagnosis of clinically insignificant cancer on repeat biopsies, so we explored ways to limit this, and to deal with its ramifications. Through carrying out a Medline literature search, we critically evaluated pertinent articles together with emphasis of our own journey in this arena to assist in the decision-making process for repeat biopsy population.

Repeat prostate biopsy and the incremental risk of clinically insignificant prostate cancer

OBJECTIVES

To determine the incremental risk of diagnosis of clinically insignificant prostate cancer with serial prostate biopsies.

METHODS

We reviewed our institutional radical prostatectomy (RP) database comprising 2411 consecutive patients undergoing RP. We then stratified patients by the prostate biopsy on which their cancer was diagnosed and correlated biopsy number with the risk of clinically insignificant disease and adverse pathology at radical prostatectomy.

RESULTS

A total of 1867 (77.4%), 281 (11.9%), and 175 (7.3%) patients underwent 1, 2, and 3 or more prostate biopsies, respectively, before RP. Increasing number of prostate biopsies was associated with increasing prostate volume (P <.01), prostate-specific antigen (P <.01), associated prostate intraepithelial neoplasia (P <.01), and increased likelihood of clinical Gleason 6 or less disease (P <.01). On pathologic analysis, increasing number of prostate biopsies was associated with increased risk of low-volume (P <.01), organ-confined (P <.01) disease. The risk of clinically insignificant disease was found to be 31.1%, 43.8%, and 46.8% in those undergoing 1, 2, and 3+ prostate biopsies, respectively. Conversely, the risk of adverse pathology was found to be 64.6%, 53.0%, and 52.0% in those undergoing 1, 2, and 3+ prostate biopsies, respectively.

CONCLUSIONS

Patients undergoing multiple prostate biopsies before RP are more likely to harbor clinically insignificant prostate cancer than those who only undergo 1 biopsy before resection. Nonetheless, the risk of adverse pathology in patients undergoing serial biopsies remains significant. The increased risk of prostate cancer overdiagnosis and overtreatment must be balanced with the continued risk of clinically significant disease when counseling patients regarding serial biopsies.

Effect of the number of biopsy cores on prostate cancer detection and staging

Digital rectal examination, serum concentration of prostate cancer-specific antigen and transrectal ultrasound-guided biopsies are currently the main diagnostic tools to detect evidence of prostate cancer. Different prostatic biopsy strategies have been proposed in order to achieve an optimal prostate cancer detection rate and an accurate characterization of prostate cancer stage and grade. We examined the role of the number of biopsy cores on prostate cancer detection rates at initial and repeat biopsies. Moreover, we examined the relationship between the number of biopsy cores and the detection of insignificant prostate cancer. Finally, we reviewed the ability of biopsy cores in predicting prostate cancer stage and grade at radical prostatectomy. We relied on a PubMed systematic review of the contemporary English language literature using the terms ‘prostate cancer’, ‘diagnosis’, ‘transrectal ultrasound’ and ‘prostate biopsy’.

Significant discrepancies between diagnostic and pathologic Gleason sums in prostate cancer: the predictive role of age and prostate-specific antigen

OBJECTIVES

To assess the discrepancies between diagnostic and pathologic Gleason sums and the predictive role of age and prostate-specific antigen (PSA) level on Gleason sum discrepancies.

METHODS

A total of 2963 patients receiving radical prostatectomy at Duke University from 1988 to 2006 were divided into two groups according to year of diagnosis: 1988 to 1999 and 2000 to 2006. The Gleason sum discrepancies were evaluated in the above groups. The predictive roles of diagnostic age (less than 50, 50 to 60, 60.1 to 70, and greater than 70 years), PSA level (less than 10, 10 to 20, and greater than 20 ng/mL), race, body mass index, and prostate weight on the discrepancies were analyzed.

RESULTS

Overall, 55.8% of diagnostic Gleason sums differed from those on final surgical pathology (58.6% in the 1988 to 1999 and 49.3% in the 2000 to 2006 groups). Diagnostic Gleason sums were undergraded in 41.2% of cases and overgraded in 12.8% of cases. Men older than 60 years were more likely to have their diagnostic Gleason sums undergraded than men younger than 50 (odds ratio in age groups less than 50, 50 to 60, 60.1 to 70, and greater than 70 years: 1.00, 2.30, 4.03, and 3.96, respectively). Biopsy Gleason sums in men with a high PSA level were more likely to be undergraded compared with the PSA group less than 10 ng/mL (odds ratio in PSA groups less than 10, 10 to 20, and greater than 20 ng/mL: 1.00, 2.11, and 3.64, respectively).

CONCLUSIONS

Significant discrepancies between diagnostic and pathologic Gleason sums remain in recent years. The rate of diagnostic Gleason sum undergrading was 3.2-fold that of overgrading. Advanced age and high PSA level were predictive of diagnostic Gleason sum undergrading, and caution should be exercised when recommending active surveillance in older men.

Prostate biopsy patterns in the CaPSURE database: evolution with time and impact on outcome after prostatectomy

PURPOSE

Significant variability exists in the urological community regarding the number of cores that should be taken during prostate biopsy. Using CaPSURE we determined trends in prostate biopsy patterns during the last decade and assessed whether changes in biopsy number have had an impact on outcomes after radical prostatectomy.

MATERIALS AND METHODS

In CaPSURE between 1995 and 2004 we identified 6,450 men with newly diagnosed prostate cancer who underwent biopsy with 6 cores or greater. The number of cores removed, number of cores positive for cancer and percent of cores containing cancer were analyzed by year of diagnosis. For 1,757 men who underwent radical prostatectomy these variables were entered into Cox proportional hazards models controlling for preoperative prostate specific antigen, biopsy Gleason sum and clinical stage to predict recurrence-free survival.

RESULTS

The mean number of removed cores increased from 6.9 in 1995 to 10.2 in 2004 (p <0.0001). The mean number of positive cores remained unchanged from 2.9 in 1995 to 3.2 in 2004 (p = 0.40). The percent of positive cores decreased from 42.6% in 1995 to 32.1% in 2004 (p <0.0001). The number and percent of positive cores were associated with recurrence-free survival after radical prostatectomy throughout the study period (each p <0.001).

CONCLUSIONS

The percent of positive cores is an independent predictor of disease recurrence after radical prostatectomy. The total number of tissue cores sampled increased during the last decade, thereby driving down the mean percent of positive cores from 42.6% to 32.1%. The trend toward an increasing number of removed cores may have contributed indirectly to improved outcomes after radical prostatectomy in the last decade.

Extended and saturation prostatic biopsy in the diagnosis and characterisation of prostate cancer: a critical analysis of the literature

OBJECTIVE

To review and critically analyse all the recent literature on the detection and characterisation of prostate cancer by means of extended and saturation protocols.

METHODS

A systematic review of the literature was performed by searching MedLine from January 1995 to April 2007. Electronic searches were limited to the English language, and the key words "prostate cancer," "diagnosis," "transrectal ultrasound (TRUS)," "prostate biopsy," and "prognosis" were used.

RESULTS

The prostate biopsy technique has changed significantly since the original Hodge sextant biopsy protocol. Several types of local anaesthesia are now available, but periprostatic nerve block (PPNB) has proved to be the most effective method to reduce pain during TRUS biopsy. It remains controversial whether PPNB should be associated with other medications. The optimal extended protocol (sextant template with at least four additional cores) should include six standard sextant biopsies, with additional biopsies (up to 12 cores) taken more laterally (anterior horn) to the base and medially to the apex. Repeat biopsies should be based on saturation biopsies (number of cores >/= 20) and should include the transition zone, especially in a patient with an initial negative biopsy. As a means of increasing accuracy of prostatic biopsy and reducing unnecessary prostate biopsy, colour and power Doppler imaging, with or without contrast enhancement, and elastography now can be successfully adopted, but their routine use is still controversial.

CONCLUSION

Extended and saturation biopsy schemes should be performed at first and repeat biopsy, respectively. The widespread use of local anaesthesia makes the procedures more comfortable.

Percent positive biopsy cores as a prognostic factor for prostate cancer treated with external beam radiation

OBJECTIVES

To examine the prognostic value of percent positive cores (PPC) in prostate cancer patients treated with external beam radiotherapy (RT).

METHODS

An institutional review board-approved, retrospective analysis was conducted on 814 patients treated with RT with or without hormonal therapy between 1984 and 2002. Percent positive cores (number of positive cores divided by total number of cores) was calculable for 591 patients with a median follow-up of 65 months. Univariate and multivariable analyses were performed using Kaplan-Meier and Cox proportional hazard methods relating PPC to other risk factors, biochemical/clinical disease-free survival (PSA-DFS), prostate cancer-specific survival (DSS), and overall survival (OS).

RESULTS

Percent positive cores was associated with stage, Gleason score (GS), pretreatment serum prostate-specific antigen (PSA) level, and use of adjunctive androgen suppression therapy. The 5-year PSA-DFS, DSS, and OS rates were 80%, 99%, and 91%, respectively, for patients with PPC less than 50%, compared with 56%, 94%, and 87% for patients with PPC 50% or greater (P <0.0001, <0.004, and <0.04, respectively). Multivariable analysis revealed that PPC, stage, GS, PSA, and androgen suppression therapy were all significantly associated with PSA-DFS, whereas only GS was associated with DSS and OS. For high, intermediate, and low-risk patients, 5-year PSA-DFS was 62% versus 39%, 80% versus 59%, and 90% versus 82% for PPC less than 50% versus PPC 50% or greater, respectively.

CONCLUSIONS

Percent positive cores predicts outcome of prostate cancer patients treated with RT, independently of other known prognostic factors. Percent positive cores may have particular use for further risk stratification within established clinical risk categories.