Pathologic Prostate Cancer Characteristics in Patients Eligible for Active Surveillance: A Head-to-Head Comparison of Contemporary Protocols

Current status of active surveillance in prostate cancer

Active surveillance (AS) is a management strategy involving close monitoring the course of disease with the expectation to intervene if the cancer progress, in a super-selected group of low-risk prostate cancer (PCa) patients. Determining AS candidates should be based on careful individualized weighing of numerous factors: life expectancy, general health condition, disease characteristics, potential side effects of treatment, and patient preference. Several protocols have been developed to determine insignificant PCa for choosing ideal AS candidates. Results regarding disease reclassification during AS have been also reported. In an effort to enhance accuracy during selection of AS candidate, there were several reports on using magnetic resonance imaging for prediction of insignificant PCa. Currently, there is an urgent need for further clinical studies regarding the criteria for recommending AS, the criteria for reclassification on AS, and the schedule for AS. Considering the racial differences in behavior of PCa between Western and Asian populations, more stringent AS protocols for Asian patients should be established from additional, well-designed, large clinical studies.

Analysis of expanded criteria to select candidates for active surveillance of low-risk prostate cancer

We aimed to analyze the value of each criterion for clinically insignificant prostate cancer (PCa) in the selection of men for active surveillance (AS) of low-risk PCa. We identified 532 men who were treated with radical prostatectomy from 2006 to 2013 who met 4 or all 5 of the criteria for clinically insignificant PCa (clinical stage ≤ T1, prostate specific antigen [PSA] density ≤ 0.15, biopsy Gleason score ≤ 6, number of positive biopsy cores ≤ 2, and no core with > 50% involvement) and analyzed their pathologic and biochemical outcomes. Patients who met all 5 criteria for clinically insignificant PCa were designated as group A (n = 172), and those who met 4 of 5 criteria were designated as group B (n = 360). The association of each criterion with adverse pathologic features was assessed via logistic regression analyses. Comparison of group A and B and also logistic regression analyses showed that PSA density > 0.15 ng ml⁻¹ and high (≥7) biopsy Gleason score were associated with adverse pathologic features. Higher (> T1c) clinical stage was not associated with any adverse pathologic features. Although ≤ 3 positive cores were not associated with any adverse pathology, ≥4 positive cores were associated with higher risk of extracapsular extension. Among potential candidates for AS, PSA density > 0.15 ng ml⁻¹ and biopsy Gleason score > 6 pose significantly higher risks of harboring more aggressive disease. The eligibility criteria for AS may be expanded to include men with clinical stage T2 tumor and 3 positive cores.

Tumor volume in insignificant prostate cancer: Increasing the threshold is a safe approach to reduce over-treatment

BACKGROUND

There are conflicting results in the literature regarding the tumor volume (TV) threshold that defines insignificant prostate cancer (PCa). In this study, we retrospectively evaluate the association of an increasing TV with biochemical recurrence (BCR) following radical prostatectomy (RP) in order to provide further clarification surrounding the TV threshold definition for insignificant PCa.

METHODS

RP patients were recruited from January 2004 to December 2009. Inclusion criteria were localized (stage ≤pT2c, negative surgical margins) Gleason 6 PCa with a total TV of ≤2.50 cm(3) . BCR was the primary outcome and defined as a PSA of ≥0.1. All cases with BCR were re-evaluated by the pathologist with reassessment of tumor grade, pathological stage and surgical margin status.

RESULTS

From 1,636 patients, 178 men (10.9%) met all inclusion criteria. Ninety-six patients (53.9%) had a TV <0.5 cm(3) and 82 patients (46.1%) had a TV 0.5-2.5 cm(3) . Three out of 178 patients (1.7%) presented with BCR during follow-up. One of these had TV <0.5 cm(3) and two had TV 0.5-2.5 cm(3) . These three cases of BCR underwent re-review of pathology; one patient was found to have a positive surgical margin and one patient was upgraded to Gleason 3 + 4 = 7. The third patient was re-reported as having positive margins for a benign hyperplastic nodule (incomplete RP specimen). Subsequently, these three cases were excluded from final analysis as they did not fit inclusion criteria. Median follow-up duration was 84 months (IQR 70-102 months). On final analysis, there were no patients with BCR, corresponding with a final BCR rate of 0% for both patients with a TV of <0.5 cm(3) and 0.5-2.5 cm(3) .

CONCLUSIONS

Our results have shown that, with a median follow-up of 84 (IQR 70-102) months, patients in our cohort with localized Gleason 6 PCa with a total TV 0.5-2.5 cm(3) have a BCR rate of 0%. We would support a more liberal total TV threshold of 2.5 cm(3) for the further development of algorithms to identify patients suitable for active surveillance.

In-parallel comparative evaluation between multiparametric magnetic resonance imaging, prostate cancer antigen 3 and the prostate health index in predicting pathologically confirmed significant prostate cancer in men eligible for active surveillance

OBJECTIVE

To assess the performance capabilities of multiparametric magnetic resonance imaging (mpMRI), the prostate health index (PHI) and prostate cancer antigen 3 (PCA3) in predicting the presence of pathologically confirmed significant prostate cancer (PCSPCa), according to the European Randomized Study of Screening Prostate Cancer definition, in a single cohort of patients who underwent radical prostatectomy (RP) but who were eligible for active surveillance (AS).

MATERIALS AND METHODS

An observational retrospective study was performed in 120 patients with prostate cancer (PCa), treated with robot-assisted RP but eligible for AS according to Prostate Cancer Research International: Active Surveillance criteria. Blood and urine specimens were collected before initial prostate biopsy for PHI and PCA3 measurements, respectively. In addition, all patients underwent mpMRI, preoperatively and 6-8 weeks after biopsy, with a 1.5T scanner using a four-to-five-channel phase array coil combined with an endorectal coin. mpMRI images were assessed and diagrams showing the prostate sextants were used to designate regions of abnormality within the prostate. Prostate findings were assigned to one of five categories according to Prostate Imaging-Reporting and Data System guidelines (PI-RADS) and considered positive for PCa if final PI-RADS score was >3 and negative if ≤3.

RESULTS

Pathologically confirmed reclassification was observed in 55 patients (45.8%). mpMRI showed good specificity and negative predictive value (0.61 and 0.73, respectively) for excluding PCSPCa compared with the PHI and PCA3. On multivariate analyses and after 1 000 bootstrapping resampling, the inclusion of both mpMRI and the PHI significantly increased the accuracy of the base model in predicting PCSPCa. For the prediction of PCSPCa, in particular, the base model had an area under the curve (AUC) of 0.71 which significantly increased by 4% with the addition of the PHI (AUC = 0.75; P < 0.01) and by 7% with the addition of mpMRI (AUC = 0.78; P < 0.01). Decision-curve analysis showed that the multivariable model with mpMRI had the highest net benefit.

CONCLUSION

In a single cohort of patients who underwent RP but who were eligible for AS, mpMRI and, to a lesser extent, the PHI, had an important role in discriminating the presence of PCSPCa; both measures could therefore be useful in the selection and monitoring of patients undergoing AS.

Validation of active surveillance criteria for pathologically insignificant prostate cancer in Asian men

OBJECTIVES

To validate the ability of contemporary active surveillance protocols to predict pathologically insignificant prostate cancer among Asian men undergoing radical prostatectomy.

METHODS

We retrospectively reviewed data on 132 patients eligible for any active surveillance criteria out of 450 patients that underwent radical prostatectomy at several institutions between 2006 and 2013. We validated the ability of seven contemporary active surveillance protocols to predict pathologically insignificant prostate cancer. Traditional and updated criteria to define pathologically insignificant prostate cancer were used. Predictive factors for pathologically insignificant prostate cancer were determined by logistic regression analysis.

RESULTS

The predictive rate for updated pathologically insignificant prostate cancer of respective active surveillance criteria was 51% for Johns Hopkins Medical Institution, 41% for Prostate Cancer Research International: Active Surveillance Study, 39% for University of Miami, 32% for University of California, San Francisco, 32% for Memorial Sloan-Kettering Cancer Center, 31% for Kakehi and 27% for University of Toronto. Predictive rates for pathologically insignificant prostate cancer in Asian men were far lower than in USA men. On multivariate analysis, predictive factors of updated pathologically insignificant cancer was prostate volume (odds ratio 1.07, P = 0.004). By adding prostate volume to Prostate Cancer Research International: Active Surveillance Study criteria, the predictive rate for updated insignificant prostate cancer was improved up to 66.7%.

CONCLUSIONS

Active surveillance can be carried out considering the clinical characteristics of prostate cancers depending on ethnicity, as current active surveillance criteria seem to have a lower predictive ability value of insignificant prostate cancer in Asian men compared with men in Western countries.

Our results of active surveillance for localized prostate cancer patients

OBJECTIVE

Active surveillance has become a management option for low-risk prostate cancer patients, while keeping the curative treatment option available. In this study, we evaluated the our results of active surveillance for localized prostate cancer patients.

MATERIAL AND METHODS

Patients diagnosed with localized prostate cancer who chose an active surveillance protocol were followed with PSA measurements, digital rectal examinations, and TRUS-guided biopsies. The patients' data and rebiopsy results were evaluated. The results were compared with the results of the patients who had definitive treatment.

RESULTS

Forty-one patients on active surveillance and 34 patients with at least one rebiopsy were included in the study. Twenty-seven patients who had more than one rebiopsy were followed for an average of 27.7 (12-78) months. Twelve patients (44.4%) had undergone definitive treatment including radical prostatectomy (n=9), and radiotherapy (n=3). There were 17 patients under surveillance after a second biopsy, and 9 (33%) of them had a third biopsy. Among these 9 patients, 7 patients were kept under surveillance, and 2 (7%) them had a fourth biopsy. Active surveillance of 15 out of 17 patients who have not undergone definitive treatment is still ongoing.

CONCLUSION

Active surveillance is a treatment option refrains low-risk prostate cancer patients from the complications of an early or unnecessary definitive treatment and related reduction in the quality of their lives. while keeping the curative treatment option available. Active surveillance can be applied safely with the appropriate patient selection, regular examinations and tests.

Not all gleason pattern 4 prostate cancers are created equal: A study of latent prostatic carcinomas in a cystoprostatectomy and autopsy series

BACKGROUND

The Gleason grading system represents the cornerstone of the management of prostate cancer. Gleason grade 4 (G4) is a heterogeneous set of architectural patterns, each of which may reflect a distinct prognostic value.

METHODS

We determined the prevalence of the various G4 architectural patterns and intraductal carcinoma (IDC) in latent prostate cancer in contemporary Russian (n = 220) and Japanese (n = 100) autopsy prostates and in cystoprostatectomy (CP) specimens (n = 248) collected in Italy. We studied the association of each G4 pattern with extraprostatic extension (EPE) and tumor volume to gain insight into their natural history. Presence of IDC and nine architectural features of Gleason grade 4 and 5 cancer were recorded.

RESULTS

The prevalence of Gleason score ≥ 7 PC was higher in the autopsy series (11%) compared to the CP series (6.5%, P = 0.04). The prevalence of IDC and carcinoma with a cribriform architecture was 2.2% and 3.4% in the autopsy series and 0.8% and 3.6% in the cystoprostatectomy series, respectively. In multivariable analysis, cribriform architecture was significantly associated with increased tumor volume (P < 0.001) and EPE (OR:11.48, 95%CI:2.30-57.16, P = 0.003). IDC was also significantly associated with EPE (OR:10.08, 95%CI:1.58-64.28, P = 0.014). Small fused glands had a strong negative association with EPE in the autopsy series (OR:0.06, 95%CI:0.01-0.58, P = 0.015).

DISCUSSION

Our study revealed that in latent prostate cancer both cribriform architecture and IDC are uniquely associated with poor pathological outcome features. In contrast, Gleason score 7 (3 + 4) cancers with small-fused gland pattern might possibly include some prostate cancers with a more indolent biology.

Neutrophil and Lymphocyte Counts as Clinical Markers for Stratifying Low-Risk Prostate Cancer

Appropriate patient selection for active surveillance is challenging.Our study of 217 patients demonstrated that the preoperative absolute neutrophil and lymphocyte counts were better predictors of aggressive oncologic features than were the neutrophil-to-lymphocyte ratio in the assessment of low-risk prostate cancer patients. Our findings suggest that routine hematologic workup could be used to further stratify low-risk prostate cancer patients.

INTRODUCTION

The neutrophil-to-lymphocyte ratio (NLR) has emerged as a ubiquitous prognostic biomarker in cancer-related inflammation, specifically in patients with metastatic castration-resistant prostate cancer (PCa). We evaluated the clinical utility of the preoperative NLR, absolute neutrophil count (ANC), and absolute lymphocyte count (ALC) as a risk stratification tool for patients with low-risk PCa.

MATERIALS AND METHODS

We identified 217 low-risk PCa patients with preoperative hematologic data who had met the criteria for active surveillance but had undergone robot-assisted radical prostatectomy at our institution from 2006 to 2015. Logistic regression models were constructed to determine whether the baseline NLR, ANC, and ALC were associated with upstaging, upgrading, and biochemical recurrence (BCR). Survival analyses were performed using the Kaplan-Meier method.

RESULTS

On multivariate analysis, a higher prostate-specific antigen level (odds ratio [OR], 1.554; 95% confidence interval [CI], 1.148-2.104), a greater number of positive cores (OR, 2.098; 95% CI, 1.043-2.104), and a higher ALC (OR, 4.311; 95% CI, 1.258-14.770) were associated with upstaging. More importantly, the 5-year biochemical recurrence-free survival was significantly lower in the high ANC group (ANC > 4.0 × 10(9)/L) compared with that of the low ANC group (P = .011). The NLR was not associated with upstaging, upgrading, or BCR in our study cohort (P = .368, P = .573, and P = .504, respectively). The only significant association with upgrading was patient age (OR, 1.106; 95% CI, 1.043-1.173).

CONCLUSION

NLR was not useful in predicting adverse pathologic outcomes in our patients with low-risk PCa. However, relative neutrophilia and lymphocytosis might indicate an early manifestation of harboring a more aggressive PCa.

PHI and PCA3 improve the prognostic performance of PRIAS and Epstein criteria in predicting insignificant prostate cancer in men eligible for active surveillance

PURPOSE

To assess the performance of prostate health index (PHI) and prostate cancer antigen 3 (PCA3) when added to the PRIAS or Epstein criteria in predicting the presence of pathologically insignificant prostate cancer (IPCa) in patients who underwent radical prostatectomy (RP) but eligible for active surveillance (AS).

METHODS

An observational retrospective study was performed in 188 PCa patients treated with laparoscopic or robot-assisted RP but eligible for AS according to Epstein or PRIAS criteria. Blood and urinary specimens were collected before initial prostate biopsy for PHI and PCA3 measurements. Multivariate logistic regression analyses and decision curve analysis were carried out to identify predictors of IPCa using the updated ERSPC definition.

RESULTS

At the multivariate analyses, the inclusion of both PCA3 and PHI significantly increased the accuracy of the Epstein multivariate model in predicting IPCa with an increase of 17 % (AUC = 0.77) and of 32 % (AUC = 0.92), respectively. The inclusion of both PCA3 and PHI also increased the predictive accuracy of the PRIAS multivariate model with an increase of 29 % (AUC = 0.87) and of 39 % (AUC = 0.97), respectively. DCA revealed that the multivariable models with the addition of PHI or PCA3 showed a greater net benefit and performed better than the reference models. In a direct comparison, PHI outperformed PCA3 performance resulting in higher net benefit.

CONCLUSIONS

In a same cohort of patients eligible for AS, the addition of PHI and PCA3 to Epstein or PRIAS models improved their prognostic performance. PHI resulted in greater net benefit in predicting IPCa compared to PCA3.

Rule-based versus probabilistic selection for active surveillance using three definitions of insignificant prostate cancer

PURPOSE

To study whether probabilistic selection by the use of a nomogram could improve patient selection for active surveillance (AS) compared to the various sets of rule-based AS inclusion criteria currently used.

METHODS

We studied Dutch and Swedish patients participating in the European Randomized study of Screening for Prostate Cancer (ERSPC). We explored which men who were initially diagnosed with cT1-2, Gleason 6 (Gleason pattern ≤3 + 3) had histopathological indolent PCa at RP [defined as pT2, Gleason pattern ≤3 and tumour volume (TV) ≤0.5 or TV ≤ 1.3 ml, and TV no part of criteria (NoTV)]. Rule-based selection was according to the Prostate cancer Research International: Active Surveillance (PRIAS), Klotz, and Johns Hopkins criteria. An existing nomogram to define probability-based selection for AS was refitted for the TV1.3 and NoTV indolent PCa definitions.

RESULTS

619 of 864 men undergoing RP had cT1-2, Gleason 6 disease at diagnosis and were analysed. Median follow-up was 8.9 years. 229 (37%), 356 (58%), and 410 (66%) fulfilled the TV0.5, TV1.3, and NoTV indolent PCa criteria at RP. Discriminating between indolent and significant disease according to area under the curve (AUC) was: TV0.5: 0.658 (PRIAS), 0.523 (Klotz), 0.642 (Hopkins), 0.685 (nomogram). TV1.3: 0.630 (PRIAS), 0.550 (Klotz), 0.615 (Hopkins), 0.646 (nomogram). NoTV: 0.603 (PRIAS), 0.530 (Klotz), 0.589 (Hopkins), 0.608 (nomogram).

CONCLUSIONS

The performance of a nomogram, the Johns Hopkins, and PRIAS rule-based criteria are comparable. Because the nomogram allows individual trade-offs, it could be a good alternative to rigid rule-based criteria.

Pathologic Outcomes in Men with Low-risk Prostate Cancer Who Are Potential Candidates for Contemporary, Active Surveillance Protocols

The purpose of this study was to determine whether contemporary active surveillance (AS) protocols could sufficiently discriminate significant from indolent tumors in men with low-risk prostate cancer. We retrospectively analyzed 312 patients with low-risk prostate cancer treated with radical prostatectomy. After exclusion of patients with fewer than 10 cores taken at biopsy and those who received neo-adjuvant treatment, 205 subjects satisfied the final inclusion criteria. Five widely accepted AS protocols were employed in this study. A total of 82.0% of the patients met the inclusion criteria of at least one protocol, and 18% did not meet any criteria of published AS protocols. A significant proportion of patients had non-organ-confined disease (8.6% to 10.6%) or a Gleason score of 7 or greater (18.6% to 23.9%) between the different AS criteria. Among patients who did not meet any AS criteria, 32.4% of patients had a pathologically insignificant cancer. Our results indicated a significant adverse pathology in patients who met the contemporary AS protocols. On the other hand, some patients in whom expectant management would be appropriate did not meet any criteria of published AS protocols. None of the clinical or histological criteria reported to date is able to sufficiently discriminate aggressive tumors from indolent ones.

Performance of biopsy factors in predicting unfavorable disease in patients eligible for active surveillance according to the PRIAS criteria

BACKGROUND

To assess the added value of biopsy factors, like maximum cancer length in a core (MCL), cumulative cancer length (CCL), cumulative length of positive cores (CLPC), percentage of cancer involvement in positive cores (CIPC) and the Prostate Cancer Research International: Active Surveillance (PRIAS) criteria in patients who underwent radical prostatectomy (RP) but eligible for active surveillance (AS).

METHODS

From January 2002 to December 2007, 750 consecutive subjects underwent RP. We identified 147 (19.07%) patients who were eligible for AS based on PRIAS criteria: clinical stage T1c or T2, PSA level of ⩽ 10 ng ml(-1), Gleason score ⩽ 6, PSA-D of <0.2 ng ml(-2) and one or two positive biopsy cores. We calculated the diagnostic accuracy of biopsy factors in determining pathological confirmed unfavorable disease. Decision curve analysis (DCA) were performed.

RESULTS

Of all subjects, 95 patients (66.43%) had favorable whereas 48 had (33.57%) unfavorable disease. On multivariate analyses, the inclusion of MCL, CCL, CLPC and CIPC significantly increased the accuracy of the base multivariate model in predicting unfavorable disease. The gain in predictive accuracy for MCL in a core, CCL, CLPC and CIPC ranged from 13 to 27%. The DCA shows that adding MCL, CCL, CLPC and CIPC resulted in a greater net benefit when the probability of ranges between 15 and 50%. The models can be applied at the cost of missing not more than 16.83% of unfavorable disease.

CONCLUSIONS

Our findings suggested that the addition of these biopsy factors to PRIAS criteria has the potential to significantly increase the ability to detect unfavorable disease.

The effect of urologist experience on choosing active surveillance for prostate cancer

PURPOSE

To evaluate the impact of the urologist's experience in selecting active surveillance (AS) versus immediate treatment (IT) for low-risk prostate cancer.

METHODS

Men with low-risk prostate cancer were enrolled from March 2011 to August 2013 at 13 medical centers in Kaiser Permanente Southern California. The AS cohort was defined as men who had cT1-T2a stage prostate cancer, prostate-specific antigen <10 ng/ml, a biopsy revealing Gleason grade ≤6, fewer than three biopsy cores positive, ≤50 % cancer in any core, and not undergone immediate therapy (surgery, radiation, other) within 6 months following diagnosis. The urologist's experience (age, number of years in practice, number of robotic surgeries performed, and fellowship experience in oncology and/or robotics) was then compared between AS and IT cohorts.

RESULTS

A total of 4754 men were diagnosed with prostate cancer, and 713 men satisfied with inclusion criteria; 433 (60.7 %) and 280 (39.3 %) chose AS and IT, respectively. A total of 87 urologists were included. Univariate and multivariate adjusted analyses revealed no differences in urologist's age or years in practice. Patients who saw urologists who had performed ≥50 robotic surgeries were less likely to choose AS (OR 0.40, 95 % CI 0.25-0.66). Patients who saw urologists with a fellowship in oncology and/or robotics were more than twice as likely to choose AS (OR 2.27, 95 % CI 1.38-3.75).

CONCLUSION

These data suggest that the decision to pursue AS may be influenced by the urologist's experience.

Magnetic Resonance Imaging Targeted Biopsy Improves Selection of Patients Considered for Active Surveillance for Clinically Low Risk Prostate Cancer Based on Systematic Biopsies

PURPOSE

Current selection criteria for active surveillance based on systematic biopsy underestimate prostate cancer volume and grade. We investigated the role of additional magnetic resonance imaging targeted biopsy in reclassifying patients eligible for active surveillance based on systematic biopsy.

MATERIALS AND METHODS

We performed a study at 2 institutions in a total of 281 men with increased prostate specific antigen. All men met certain criteria, including 1) prebiopsy magnetic resonance imaging, 12-core transrectal systematic biopsy and 2 additional magnetic resonance imaging targeted biopsies of lesions suspicious for cancer during the same sequence as systematic biopsy, and 2) eligibility for active surveillance based on systematic biopsy results. Criteria for active surveillance were prostate specific antigen less than 10 ng/ml, no Gleason grade 4/5, 5 mm or less involvement of any biopsy core and 2 or fewer positive systematic biopsy cores. Patient characteristics were compared between reclassified and nonreclassified groups based on magnetic resonance imaging targeted biopsy results.

RESULTS

On magnetic resonance imaging 58% of the 281 patients had suspicious lesions. Magnetic resonance imaging targeted biopsy was positive for cancer in 81 of 163 patients (50%). Of 281 patients 28 (10%) were reclassified by magnetic resonance imaging targeted biopsy as ineligible for active surveillance based on Gleason score in 8, cancer length in 20 and Gleason score plus cancer length in 9. Suspicious areas on magnetic resonance imaging were in the anterior part of the prostate in 15 of the 28 men (54%). Reclassified patients had a smaller prostate volume (37 vs 52 cc) and were older (66.5 vs 63 years) than those who were not reclassified (p < 0.05).

CONCLUSIONS

Magnetic resonance imaging targeted biopsy reclassified 10% of patients who were eligible for active surveillance based on systematic biopsy. Its incorporation into the active surveillance eligibility criteria may decrease the risk of reclassification to higher stages during followup.

A urine-based methylation signature for risk stratification within low-risk prostate cancer

Background:

Prostate cancer overdiagnosis and overtreatment represents a major problem. Many men with low-grade disease on biopsy are undergraded and they harbour high-grade disease at prostatectomy with no reliable way to identify these men. We used a novel urine-based 2-gene methylation test to identify prostate cancers with aggressive features.

Methods:

Following a proof of concept study in 100 post-radical prostatectomy tissue samples, urine samples were tested from 665 men at multiple U.S. centers undergoing prostate needle biopsy for elevated prostate-specific antigen (2–10 ng ml⁻¹). A prediction model was then developed from a combination of clinical factors and the urine-based markers. It was then prospectively tested for accurate prediction of adverse disease (surgical Gleason score ⩾7 and/or a pathological stage ⩾T3a) using urine from a separate cohort of 96 men before radical prostatectomy.

Results:

Among pre-prostatectomy men with a biopsy Gleason score <7, 41% had adverse disease of which 100% were correctly identified by the test with a negative predictive value of 100% (95% confidence interval, 86–100%).

Conclusions:

This urine-based test accurately identifies men with clinical low-risk disease who do not have adverse pathology in their prostates and would be excellent candidates for active surveillance.

Incidence and Predictors of Upgrading and Up Staging among 10,000 Contemporary Patients with Low Risk Prostate Cancer

PURPOSE

We determined the incidence of pathological upgrading and up staging for contemporary, clinically low risk patients, and identified predictors of having occult, advanced disease to inform the selection of patients for active surveillance.

MATERIALS AND METHODS

We studied 10,273 patients in the SEER database diagnosed with clinically low risk disease (cT1c/T2a, prostate specific antigen less than 10 ng/ml, Gleason 3 + 3 = 6) in 2010 to 2011 and treated with prostatectomy. The primary outcome was the incidence of upgrading to pathological Gleason score 7-10 or up staging to pathological T3-T4/N1 disease. Multivariable logistic regression of cases with complete biopsy data (5,581) identified significant predictors of upgrading or up staging, which were then used to create a risk stratification table.

RESULTS

At prostatectomy 44% of cases were upgraded and 9.7% were up staged. Multivariable analysis of 5,581 patients showed age, prostate specific antigen and percent positive cores (all p < 0.001) but not race were associated with occult, advanced disease. With these variables dichotomized at the median, age older than 60 years (AOR 1.39), prostate specific antigen greater than 5.0 ng/ml (AOR 1.28) and more than 25% positive cores (AOR 1.76) were significantly associated with upgrading (all p < 0.001). Similarly, age older than 60 years (AOR 1.42), prostate specific antigen greater than 5.0 ng/ml (AOR 1.44) and more than 25% positive cores (AOR 2.26) were associated with up staging (all p < 0.001). Overall 60% of 5,581 low risk cases with prostate specific antigen 7.5 to 9.9 ng/ml and more than 25% positive cores were upgraded. This study is limited by possible bias introduced by only using patients selected for prostatectomy.

CONCLUSIONS

Nearly half of clinically low risk patients harbor Gleason 7 or greater, or pT3 or greater disease, and should be risk stratified by prostate specific antigen and percent positive cores for consideration of further testing before deciding on active surveillance.

What is the optimal definition of misclassification in patients with very low-risk prostate cancer eligible for active surveillance? Results from a multi-institutional series

BACKGROUND

The risk of unfavorable prostate cancer in active surveillance (AS) candidates is nonnegligible. However, what represents an adverse pathologic outcome in this setting is unknown. We aimed at assessing the optimal definition of misclassification and its effect on recurrence in AS candidates treated with radical prostatectomy (RP).

MATERIALS AND METHODS

Overall, 1,710 patients eligible for AS according to Prostate Cancer Research International: Active Surveillance criteria treated with RP between 2000 and 2013 at 3 centers were evaluated. Patients were stratified according to pathology results at RP: organ-confined disease and pathologic Gleason score ≤ 6 (group 1); organ-confined disease and Gleason score 3+4 (group 2); and non-organ-confined disease, Gleason score ≥ 4+3, and nodal invasion (group 3). Biochemical recurrence (BCR) was defined as 2 consecutive prostate-specific antigen (PSA) ≥ 0.2 ng/ml. Kaplan-Meier curves assessed time to BCR. Multivariable Cox regression analyses tested the association between pathologic features and BCR. Multivariable logistic regression analyses identified the predictors of adverse pathologic characteristics.

RESULTS

Overall, 926 (54.2%), 653 (33.0%), and 220 (12.9%) patients were categorized in groups 1, 2, and 3, respectively. Median follow-up was 32.2 months. The 5-year BCR-free survival rate was 94.2%. Patients in group 3 had lower BCR-free survival rates compared with those in group 1 (79.1% vs. 97.0%, P<0.001). No differences were observed between patients included in group 1 vs. group 2 (97.0% vs. 94.7%, P = 0.1). These results were confirmed at multivariable analyses and after stratification according to margin status. Older age and PSA density ≥ 10 ng/ml/ml were associated with higher risk of unfavorable pathologic characteristics (i.e., inclusion in group 3; all P<0.001).

CONCLUSIONS

Among patients eligible for AS treated with RP, only men with Gleason score ≥ 4+3 or non-organ-confined disease at final pathology were at increased risk of BCR. These individuals represent the real misclassified AS patients, who can be predicted based on older age and higher PSA density.

Five-year follow-up of active surveillance for prostate cancer: A Canadian community-based urological experience

INTRODUCTON

We assessed oncological outcomes of active surveillance (AS) using a community database and identified factors associated with disease reclassification on surveillance biopsy.

METHODS

A retrospective review was performed on 200 men on AS. Prostate-specific antigen (PSA) was measured every 3 to 6 months. Prostate biopsies were performed every 1 to 4 years, and at the individual physician's discretion. Disease reclassification was defined as clinical T1 to cT2 progression, or histologically as >2 cores positive, Gleason score >6, or >50% core involvement on surveillance biopsy. Multivariate Cox regression analysis evaluated factors associated with disease reclassification. Kaplan-Meier survival curves were plotted.

RESULTS

We assessed a heterogeneous cohort of 86 patients, with a median age 67.2 years, who received ≥1 surveillance biopsies. The median follow-up was 5.2 years. The median times to first and second surveillance biopsies were 730 and 763 days, respectively. Overall, 47% of patients were reclassified on surveillance biopsy after a median 2.1 years. Factors associated with disease reclassification were PSA density >0.20 (p < 0.0001, hazard ratio [HR] 4.55, 95% confidence interval [CI] 2.116-9.782) and ≥3 positive cores (p = 0.0152, HR 3.956, 95% CI 1.304-12.003) at diagnosis, and number of positive cores on surveillance biopsy. In total, 25 (29%) patients received delayed intervention, with a median time to intervention of 2.6 years. The median time on AS was 4.4 years, with an overall survival of 95% and prostate-specific survival of 100%.

CONCLUSIONS

Our community study supports AS to reduce over-treatment of prostate cancer. PSA density >0.20 and ≥3 cores positive are associated with disease reclassification on surveillance biopsy.

Does active surveillance lead to anxiety and stress?

For men with prostate cancer (PC), patient care and treatment recommendations should not focus solely on the disease but should also take into account the views of the patient. The diagnosis and consequences of monitoring or treatment should be fully explained. Recommending Active Surveillance (AS) for the monitoring of a proven low-risk, low-volume prostate cancer should ensure that the psychological impact of AS is taken into account and included in a holistic approach to patient and disease management. This article is a rapid literature search relating to AS, and how the psychological impact of a cancer diagnosis may influence patient choice.

The presence of high-grade prostatic intraepithelial neoplasia or atypia on prostate biopsy does not adversely affect prostatectomy outcomes for patients otherwise eligible for active surveillance

OBJECTIVE

To investigate if the presence of concomitant high-grade prostatic intraepithelial neoplasia (HGPIN) or atypical small acinar proliferation (ASAP) on biopsy increases the risk of occult adverse pathology in patients otherwise suitable for active surveillance (AS).

METHODS

Patients with D'Amico low-risk prostate cancer on ≥ 10-core biopsy who underwent radical prostatectomy at our academic center were evaluated for eligibility for AS by either Epstein criteria or Memorial Sloan Kettering Cancer Center (MSKCC) criteria. Prostatectomy specimens of patients eligible for AS were compared to determine if the presence of clinical HGPIN or ASAP affected the primary outcomes of pathologic upstaging and Gleason score upgrading.

RESULTS

Of 553 patients with low-risk prostate cancer, 400 patients (72.3%) met the MSKCC criteria, whereas only 170 patients (30.7%) met the Epstein criteria. HGPIN was present in approximately 32%, and ASAP in approximately 12%, of each AS cohort. On univariate and multivariate analyses, HGPIN and ASAP had no impact on the rate of upgrading and upstaging in either Epstein or MSKCC AS-eligible patients. Furthermore, the presence of HGPIN and ASAP had no impact on the 5-year biochemical recurrence-free survival.

CONCLUSION

The presence of HGPIN or ASAP does not increase the risk of upgrading, upstaging, or adverse pathology at the time of prostatectomy for patients who meet the AS criteria. If otherwise suitable, HGPIN and ASAP should not impact the decision to choose AS. However, analysis of prospective AS trials is required to determine if HGPIN or ASAP impacts tumor progression once on AS.

Can contemporary patients with biopsy Gleason score 3+4 be eligible for active surveillance?

INTRODUCTION

We analyzed whether expansion of existing active surveillance (AS) protocols to include men with biopsy Gleason score (GS) 3+4 prostate cancer (PCa) would significantly alter pathologic and biochemical outcomes of potential candidates of AS.

METHODS

Among patients who underwent radical prostatectomy at our center between 2006 and 2013, we identified 577 patients (group A) who preoperatively fulfilled at least one of 6 different AS criteria. Also, we identified 217 patients (group B) with biopsy GS 3+4 but fulfilled non-GS criteria from at least one of 6 AS criteria. Designating group C as expanded group incorporating all patients in group A and B, we compared risk of unfavorable disease (pathologic GS ≥ 4+3 and/or pathologic T stage ≥ pT3a) and biochemical recurrence (BCR)-free survival between groups.

RESULTS

Rates of unfavorable disease were not significantly different between patients of group A and C who met AS criteria from 5 institutions (all p>0.05), not including University of Toronto (p < 0.001). Also BCR-free survivals were not significantly different between patients in group A and C meeting each of 6 AS criteria (all p > 0.05). Among group B, PSAD > 0.15 ng/mL/cm3 (p = 0.011) and tumor length of biopsy GS 3+4 core > 4 mm (p = 0.007) were significant predictors of unfavorable disease. When these two criteria were newly applied in defining group B, rates of unfavorable disease in group A and B was 15.6% and 14.7%, respectively (p = 0.886).

CONCLUSION

Overall rate of pathologically aggressive PCa harbored by potential candidates for AS may not be increased significantly with expansion of criteria to biopsy GS 3+4 under most contemporary AS protocols. PSAD and tumor length of biopsy GS 3+4 core may be useful predictors of more aggressive disease among potential candidates for AS with biopsy GS 3+4.

Insignificant disease among men with intermediate-risk prostate cancer

PURPOSE

A paucity of data exists on the insignificant disease potentially suitable for active surveillance (AS) among men with intermediate-risk prostate cancer (PCa). We tried to identify pathologically insignificant disease and its preoperative predictors in men who underwent radical prostatectomy (RP) for intermediate-risk PCa.

METHODS

We analyzed data of 1,630 men who underwent RP for intermediate-risk disease. Total tumor volume (TTV) data were available in 332 men. We examined factors associated with classically defined pathologically insignificant cancer (organ-confined disease with TTV ≤0.5 ml with no Gleason pattern 4 or 5) and pathologically favorable cancer (organ-confined disease with no Gleason pattern 4 or 5) potentially suitable for AS. Decision curve analysis was used to assess clinical utility of a multivariable model including preoperative variables for predicting pathologically unfavorable cancer.

RESULTS

In the entire cohort, 221 of 1,630 (13.6 %) total patients had pathologically favorable cancer. Among 332 patients with TTV data available, 26 (7.8 %) had classically defined pathologically insignificant cancer. Between threshold probabilities of 20 and 40 %, decision curve analysis demonstrated that using multivariable model to identify AS candidates would not provide any benefit over simply treating all men who have intermediate-risk disease with RP.

CONCLUSION

Although a minority of patients with intermediate-risk disease may harbor pathologically favorable or insignificant cancer, currently available conventional tools are not sufficiently able to identify those patients.

Can we expand active surveillance criteria to include biopsy Gleason 3+4 prostate cancer? A multi-institutional study of 2,323 patients

OBJECTIVE

To test the expandability of active surveillance (AS) to Gleason score 3+4 cancers by assessing the unfavorable disease risk in a large multi-institutional cohort.

MATERIALS AND METHODS

We performed a retrospective analysis including 2,323 patients with localized Gleason score 3+4 prostate cancer who underwent a radical prostatectomy between 2005 and 2013 from 6 academic centers. We analyzed the rates of biopsy downgrading/upgrading and advanced stage in the overall cohort by employing standardized AS criteria (using biopsy Gleason score 3+4).

RESULTS

The final pathologic Gleason score was 3+3 = 6 in 8%, 3+4 = 7 in 67%, 4+3 = 7 in 20%, and 8 to 10 in 5% cases. The overall rate of unfavorable disease (upgrading or advanced stage or both) was 46%. In multivariable analysis, prostate-specific antigen (PSA) level>10 ng/ml, PSA density (PSAD) >0.15 ng/ml/g, clinical stage >T1, and>2 positive cores were predictors of unfavorable disease. According to the AS criteria used, the risk of unfavorable disease ranged from 30% to 42%. In patients without any risk factor (PSA level≤ 10 ng/ml, PSAD ≤ 0.15 ng/ml/g, T1c, and ≤ 2 positive cores), the unfavorable disease rate was 19%. The main limitations of this study are the retrospective design and nonstandardization of pathologic assessment between centers.

CONCLUSIONS

Approximately half of patients with biopsy Gleason score 3+4 cancer have unfavorable disease at final pathology. Nevertheless, expanding AS eligibility to these patients may be acceptable provided adherence to strict selection criteria leading to a<20% risk of unfavorable disease. Future tools for selection such as magnetic resonance imaging, early rebiopsy, and serum markers may be especially beneficial in this group of patients.

Analysis of different tumor volume thresholds of insignificant prostate cancer and their implications for active surveillance patient selection and monitoring

Purpose:

We compared oncological outcomes according to tumor volume (TV) thresholds defining both classical and updated insignificant prostate cancer (IPC), since the TV threshold can be used as clinical parameter for active surveillance.

Methods:

Between 2001 and 2012, we retrospectively analyzed 331 organ-confined prostate cancer patients who had preoperative Gleason score 6, preoperative PSA under 10 ng/mL and pathologic TV less than 1.3 mL. Among them, 81 of 331 (24.5%) had Gleason grade 4/5 disease postoperatively. Patients were stratified into two groups: (1) TV less than 0.5 mL, using the classical definition; and (2) TV between 0.5 mL and 1.3 mL, using the range of updated definition. We compared biochemical recurrence (BCR)-free survival and identified independent predictors of BCR in each group.

Results:

Group 2 had more Gleason grade 4/5 disease than group 1 (P<0.001). On multivariate analysis, Gleason grade 4/5 disease was not associated with BCR in group 1 (P=0.132). However, it was an independent predictor for BCR in group 2 (P=0.042). BCR-free survival were not significantly different according to the presence of Gleason grade 4/5 disease in group 1 (P=0.115). However, in group 2, it was significantly different according to the presence of Gleason grade 4/5 disease (P=0.041).

Conclusions:

Although the TV thresholds of the two definitions of IPC vary only slightly, this difference was enough to result in different clinical course if Gleason grade 4/5 disease was present. Therefore, the updated IPC TV threshold should be carefully applied as clinical parameter for active surveillance.

Seventh Joint Meeting of K-J-CaP and CaPSURE: extending the global initiative to improve prostate cancer management

This report summarizes the presentations and discussions that took place at the Seventh Joint Meeting of the Korea–Japan Study Group of Prostate Cancer (K-J-CaP) and the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) held in Seoul, Korea, in September 2013. The original J-CaP and CaPSURE Joint Initiative has now been established since 2007 and since the initial collaboration between research teams in the United States (US) and Japan, the project has expanded to include several other Asian countries. The objective of the initiative is to analyze and compare data for prostate cancer patients in the participating countries, looking at similarities and differences in patient management and outcomes. Until now the focus has been primarily on data generated within J-CaP and CaPSURE, both large-scale, longitudinal, observational databases of prostate cancer patients in Japan and the US, respectively. This year’s meeting was hosted for the first time in Korea which has recently established its own national database–K-CaP–to add to the wealth of data generated by J-CaP and CaPSURE. As a newly-developed database, K-CaP has also provided a valuable ‘template’ for other countries, such as China and Indonesia, planning to establish their own national databases and this will ultimately allow greater opportunities for international data comparisons. A range of topics was discussed at this Seventh Joint Meeting including comparison of outcomes following androgen deprivation therapy or radical prostatectomy in patients with localized prostate cancer, the use of active surveillance as a treatment option and the triggers for intervention when employing this regimen, patient quality of life during treatment, the impact of comorbidities on outcomes, and a comparison of recent outcomes data between J-CaP and CaPSURE. The participants recognized that prostate cancer was now a global disease and therefore major insights into understanding and improving the management of this condition would arise from global interactions such as this joint initiative.

Predictive factors of unfavorable prostate cancer in patients who underwent prostatectomy but eligible for active surveillance

PURPOSE

To investigate the predictive factors of unfavorable prostate cancer in Korean men who underwent radical prostatectomy but eligible for active surveillance according to Epstein criteria.

METHODS

We retrospectively reviewed the medical records of 2,036 patients who underwent radical prostatectomy for prostate cancer between 1994 and 2011. Among these, 233 patients were eligible for active surveillance based on Epstein criteria. Unfavorable prostate cancer was defined as pathologic Gleason sum ≥7 or non-organ-confined disease. We investigated pathologic outcomes and predictive factors for unfavorable prostate cancer.

RESULTS

Of 233 cases, 91 patients (39.1%) were pathologic Gleason sum ≥7, 11 (4.7%) had extracapsular extension, and three (1.3%) had seminal vesicle invasion. Ninety-eight patients (42.1%) had unfavorable prostate cancer. When comparing clinically insignificant and significant prostate cancer, there were significant differences in mean age (P=0.007), prostate volume (P=0.021), prostate-specific antigen (PSA) density (P=0.03), maximum tumor volume in biopsy core (P<0.001), and rate of two positive cores (P=0.001). On multivariate analysis, age (P=0.015), PSA density (P=0.017) and two positive cores (P=0.001) were independent predictive factors for unfavorable prostate cancer.

CONCLUSIONS

A significant proportion of patients who were candidates for active surveillance had unfavorable prostate cancer. Age, PSA density, and two positive cores were independent significant predictive factors for unfavorable prostate cancer. These factors should be considered when performing active surveillance.

Prostate volume and biopsy tumor length are significant predictors for classical and redefined insignificant cancer on prostatectomy specimens in Japanese men with favorable pathologic features on biopsy

Background

Gleason pattern 3 less often has molecular abnormalities and often behaves indolent. It is controversial whether low grade small foci of prostate cancer (PCa) on biopsy could avoid immediate treatment or not, because substantial cases harbor unfavorable pathologic results on prostatectomy specimens. This study was designed to identify clinical predictors for classical and redefined insignificant cancer on prostatectomy specimens in Japanese men with favorable pathologic features on biopsy.

Methods

Retrospective review of 1040 PCa Japanese patients underwent radical prostatectomy between 2006 and 2013. Of those, 170 patients (16.3%) met the inclusion criteria of clinical stage ≤ cT2a, Gleason score (GS) ≤ 6, up to two positive biopsies, and no more than 50% of cancer involvement in any core. The associations between preoperative data and unfavorable pathologic results of prostatectomy specimens, and oncological outcome were analyzed. The definition of insignificant cancer consisted of pathologic stage ≤ pT2, GS ≤ 6, and an index tumor volume < 0.5 mL (classical) or 1.3 mL (redefined).

Results

Pathologic stage ≥ pT3, upgraded GS, index tumor volume ≥ 0.5 mL, and ≥ 1.3 mL were detected in 25 (14.7%), 77 (45.3%), 83 (48.8%), and 53 patients (31.2%), respectively. Less than half of cases had classical (41.2%) and redefined (47.6%) insignificant cancer. The 5-year recurrence-free survival was 86.8%, and the insignificant cancers essentially did not relapse regardless of the surgical margin status. MRI-estimated prostate volume, tumor length on biopsy, prostate-specific antigen density (PSAD), and findings of magnetic resonance imaging were associated with the presence of classical and redefined insignificant cancer. Large prostate volume and short tumor length on biopsy remained as independent predictors in multivariate analysis.

Conclusions

Favorable features of biopsy often are followed by adverse pathologic findings on prostatectomy specimens despite fulfilling the established criteria. The finding that prostate volume is important does not simply mirror many other studies showing PSAD is important, and the clinical criteria for risk assessment before definitive therapy or active surveillance should incorporate these significant factors other than clinical T-staging or PSAD to minimize under-estimation of cancer in Japanese patients with low-risk PCa.

Is active surveillance a safe alternative in the management of localized prostate cancer? Pathological features of radical prostatectomy specimens in potential candidates for active surveillance

INTRODUCTION AND OBJECTIVE

Active surveillance (AS) has become an accepted alternative for patients with low risk prostate cancer. The purpose of AS is to defer definitive therapy in these patients to avoid treatment-related complications. Our aim was to determine the pathological features of the surgical specimen from potential AS candidates that underwent radical prostatectomy (RP).

MATERIALS AND METHODS

We retrospectively reviewed a group of patients submitted to RP who met criteria for AS: Gleason score (GS) ≤ 3+3 = 6, PSA ≤ 10ng/mL, T1c - T2a,< 1/3 of positive cores, < 50% of involvement in any core and PSA density < 0.15. We determined the concordance between GS in biopsy and RP specimen (RPS). Other pathological features of the RPS were also analyzed, including surgical margins, extracapsular extension, seminal vesicles and lymph node involvement.

RESULTS

We identified 167 patients subjected to RP that met the criteria for AS. Fifty two patients (31.1%) had a GS > 6 in the RPS (GS 7 n = 49; GS 8 n = 3). Extracapsular extension, seminal vesicle and lymph node involvement was found in 6.1%, 3.1% and 1.2% of the specimens, respectively.

CONCLUSION

In this study a significant proportion of potential candidates for AS showed features of aggressive and/or high-risk tumors in the RPS. Therefore, before considering a patient for an AS protocol, a proper and strict selection must be performed, and informed consent is crucial for these patients.

Identification of pathologically insignificant prostate cancer is not accurate in unscreened men

Background:

Identification of men harbouring insignificant prostate cancer (PC) is important in selecting patients for active surveillance. Tools have been developed in PSA-screened populations to identify such men based on clinical and biopsy parameters.

Methods:

Prospectively collected case series of 848 patients was treated with radical prostatectomy between July 2007 and October 2011 at an English tertiary care centre. Tumour volume was assessed by pathological examination. For each tool, receiver operator characteristics were calculated for predicting insignificant disease by three different criteria and the area under each curve compared. Comparison of accuracy in screened and unscreened populations was performed.

Results:

Of 848 patients, 415 had Gleason 3+3 disease on biopsy. Of these, 32.0% had extra-prostatic extension and 50.2% were upgraded. One had positive lymph nodes. Two hundred and six (24% of cohort) were D'Amico low risk. Of these, 143 had more than two biopsy cores involved. None of the tools evaluated has adequate discriminative power in predicting insignificant tumour burden. Accuracy is low in PSA-screened and -unscreened populations.

Conclusions:

In our unscreened population, tools designed to identify insignificant PC are inaccurate. Detection of a wider size range of prostate tumours in the unscreened may contribute to relative inaccuracy.

Revised Gleason grading system is a better predictor of indolent prostate cancer at the time of diagnosis: retrospective clinical-pathological study on matched biopsy and radical prostatectomy specimens

INTRODUCTION/BACKGROUND

The increase of prostate cancer diagnosis after the introduction of prostate-specific antigen (PSA) screening resulted in overtreatment of patients with low risk tumors. The histological Gleason score (GS) revised in 2005 by the International Society of Urological Pathology (ISUP) is currently the most reliable tool to separate aggressive from indolent prostate cancer.

MATERIALS AND METHODS

Using the new 2005 GS criteria we retrospectively evaluated biopsy and surgical samples of 1344 patients who underwent radical prostatectomy in our institution. According to the new GS criteria we then selected 134 patients who would have been suitable for active surveillance at the time of biopsy (at least 2 positive cores, PSA < 10 ng/mL, GS ≤ 6). We finally assessed the accuracy of the revised GS in biopsy to predict indolent cancer in the prostatectomy specimens.

RESULTS

The mean GS increased from 6 to 7 after histological revision in biopsy and prostatectomy specimens. Histological revision determined a significant decrease of patients with GS ≤ 6 and an increase of those with GS ≥ 7 (all P < .001). The average of pathologically indolent disease (organ-confined, GS ≤ 6 at surgery, tumor of any volume) significantly decreased after histological revision (P < .001).

CONCLUSION

The revised ISUP 2005 criteria for Gleason grading provided better stratification of GS ≤ 6 prostate cancer and improved the accuracy for the histological diagnosis of indolent prostate cancer in biopsy and radical prostatectomy specimens.

Imaging and Markers as Novel Diagnostic Tools in Detecting Insignificant Prostate Cancer: A Critical Overview

Recent therapeutic advances for managing low-risk prostate cancer include the active surveillance and focal treatment. However, locating a tumor and detecting its volume by adequate sampling is still problematic. Development of predictive biomarkers guiding individual therapeutic choices remains an ongoing challenge. At the same time, prostate cancer magnetic resonance imaging is gaining increasing importance for prostate diagnostics. The high morphological resolution of T2-weighted imaging and functional MRI methods may increase the specificity and sensitivity of diagnostics. Also, recent studies founded an ability of novel biomarkers to identify clinically insignificant prostate cancer, risk of progression, and association with poor differentiation and, therefore, with clinical significance. Probably, the above mentioned methods would improve tumor characterization in terms of its volume, aggressiveness, and focality. In this review, we attempted to evaluate the applications of novel imaging techniques and biomarkers in assessing the significance of the prostate cancer.

The impact of baseline [-2]proPSA-related indices on the prediction of pathological reclassification at 1 year during active surveillance for low-risk prostate cancer: the Japanese multicenter study cohort

Purpose

Active surveillance (AS) is one potential solution to avoiding the overtreatment of favorable prostate cancer. By handling the AS strategy more safely, tumor aggressiveness may be evaluated more accurately. The aim of the present study was to evaluate the predictive impact of baseline prostate-specific antigen (PSA) isoform [−2]proPSA (p2PSA)-related indices on the pathological reclassification at 1 year during an AS program.

Methods

Between 2002 and 2003, 134 males diagnosed with low-risk prostate cancer were registered in the Japanese multicenter study cohort as candidates for AS, and 118 (88 %) males actually proceeded to AS. Of the 118 patients, the 67 that underwent protocol biopsy at 1 year after beginning AS were enrolled in the present study. The predictive significance of various baseline clinicopathological features and p2PSA-related indices on pathological reclassification at 1 year after beginning AS were investigated.

Results

The pathological reclassification rate was 37.3 %. According to the univariate analysis, prostate volume (p = 0.049), number of biopsy cores (p = 0.047), percentage of positive biopsy cores (p = 0.023), p2PSA to free PSA ratio (%p2PSA) (p = 0.003) and prostate health index (phi) (p = 0.010) at baseline were significantly different between the reclassification and non-reclassification groups. By multivariate logistic regression analysis, baseline %p2PSA (p = 0.008) and phi (p = 0.008) were the only independent predictive factors for pathological upgrade at 1 year after AS commencement.

Conclusions

Baseline %p2PSA and phi may predict the pathological reclassification at 1 year after starting AS, which could be due to the under detection of clinically significant prostate cancer at AS enrollment.

The role of magnetic resonance imaging in the diagnosis and management of prostate cancer

BACKGROUND

The diagnosis of prostate cancer has long been plagued by the absence of an imaging tool that reliably detects and localises significant tumours. Recent evidence suggests that multi-parametric MRI could improve the accuracy of diagnostic assessment in prostate cancer. This review serves as a background to a recent USANZ position statement. It aims to provide an overview of MRI techniques and to critically review the published literature on the clinical application of MRI in prostate cancer.

TECHNICAL ASPECTS

The combination of anatomical (T2-weighted) MRI with at least two of the three functional MRI parameters - which include diffusion-weighted imaging, dynamic contrast-enhanced imaging and spectroscopy - will detect greater than 90% of significant (moderate to high risk) tumours; however MRI is less reliable at detecting tumours that are small (<0.5 cc), low grade (Gleason score 6) or in the transitional zone. The higher anatomical resolution provided by 3-Tesla magnets and endorectal coils may improve the accuracy, particularly in primary tumour staging.

SCREENING

The use of mpMRI to determine which men with an elevated PSA should undergo biopsy is currently the subject of two large clinical trials in Australia. MRI should be used with caution in this setting and then only in centres with established uro-radiological expertise and quality control mechanisms in place. There is sufficient evidence to justify using MRI to determine the need for repeat biopsy and to guide areas in which to focus repeat biopsy.

IMAGE-DIRECTED BIOPSY

MRI-directed biopsy is an exciting concept supported by promising early results, but none of the three proposed techniques have so far been proven superior to standard biopsy protocols. Further evidence of superior accuracy and core-efficiency over standard biopsy is required, before their costs and complexities in use can be justified.

TREATMENT SELECTION AND PLANNING

When used for primary-tumour staging (T-staging), MRI has limited sensitivity for T3 disease, but its specificity of greater than 95% may be useful in men with intermediate-high risk disease to identify those with advanced T3 disease not suitable for nerve sparing or for surgery at all. MRI appears to be of value in planning dosimetry in men undergoing radiotherapy, and in guiding selection for and monitoring on active surveillance.

Prostate cancer and the increasing role of active surveillance

Prostate cancer (PC) is the most often diagnosed non-skin cancer and the second leading cause of cancer-related death among men in the United States. As a result, for many years the American Urological Association (AUA) and the American Cancer Society have issued statements recommending screening for PC, resulting in its widespread implementation in the United States. Recently, the United States Preventative Services Task Force gave PC screening a recommendation of D, that is, against PC screening for all men. The AUA countered this recommendation, stating that since the development of PC screening using prostate-specific antigen, a reduction in PC-specific mortality has been seen, and that the risk reduction occurred in a setting in which many of the patients were not aggressively treated for prostate cancer. Active surveillance may be described as a method to potentially delay or obviate the need for treatment in men with clinically insignificant PC or PC thought to be at low risk for progression. Studies have shown no significant difference in outcome or pathology between men with low risk PC who receive treatment at the point of progression and those undergoing immediate treatment. Ongoing studies are evaluating the efficacy and utility of active surveillance for low-risk PC. Interim results of these studies have shown that approximately 30% of patients progress on active surveillance. However, "progression" does not necessarily mean treatment failure; rarely do patients develop locally advanced or metastatic disease. Active surveillance has also been shown to be cost-effective when compared with immediate treatment for PC. Longer follow-up may continue to show an increased benefit of active surveillance as a reasonable initial approach to the management of men with low-risk, clinically localized PC.

Utility of diffusional kurtosis imaging as a marker of adverse pathologic outcomes among prostate cancer active surveillance candidates undergoing radical prostatectomy

OBJECTIVE

The purpose of this study was to compare findings at nongaussian diffusional kurtosis imaging and conventional diffusion-weighted MRI as markers of adverse pathologic outcomes among prostate cancer patients who are active surveillance candidates and choose to undergo prostatectomy.

MATERIALS AND METHODS

Fifty-eight active surveillance candidates (prostate-specific antigen concentration, < 10 ng/mL; clinical tumor category less than T2a; Gleason score, 3 + 3; ≤ 25% of biopsy cores positive for tumor; ≤ 50% tumor involvement of any individual core; ≤ 20% tumor involvement across all cores) who underwent prostatectomy and preoperative 3-T MRI including diffusional kurtosis imaging (b values, 0, 500, 1000, 1500, and 2000 s/mm(2)) were included. Adverse pathologic features at prostatectomy were defined using two schemes of varying stringency. One scheme (less stringent) was presence of a Gleason score greater than 6 or extracapsular extension (n = 19). The other scheme (more stringent) was presence of a Gleason score greater than 6, extracapsular extension, or an index tumor 10 mm or larger (n = 35). Parametric maps displaying standard apparent diffusion coefficient (ADC), kurtosis (K) representing nongaussian diffusion behavior, and diffusion (D) representing a diffusion coefficient adjusted for nongaussian (kurtosis) behavior were reviewed, and the most abnormal region was recorded for each metric. Associations between these metrics and the presence of adverse final pathologic findings were assessed with unpaired Student t tests and receiver operating characteristic analyses.

RESULTS

For both schemes, only D was significantly lower in patients with adverse final pathologic findings (p = 0.006, p = 0.025). K tended to be greater in patients with adverse final pathologic findings for the more stringent scheme (p = 0.072). ADC was not significantly different in the presence of adverse final pathologic findings for either scheme (p = 0.357, p = 0.383). With either scheme, D had a larger area under the receiver operating characteristics curve (AUC) for predicting adverse final pathologic results (AUC, 0.691 and 0.743) than did ADC (AUC, 0.569 and 0.655) or K (AUC, 0.617 and 0.714), but the difference was not significant (p = 0.183, p = 0.734).

CONCLUSION

Preliminary results suggest that diffusional kurtosis imaging findings may have more value than findings at conventional diffusion-weighted MRI as a marker of adverse final pathologic outcome among active surveillance candidates.

Development and multi-institutional validation of an upgrading risk tool for Gleason 6 prostate cancer

BACKGROUND

Many patients with low-risk prostate cancer (PC) who are diagnosed with Gleason score 6 at biopsy are ultimately found to harbor higher grade PC (Gleason ≥ 7) at radical prostatectomy. This finding increases risk of recurrence and cancer-specific mortality. Validated clinical tools that are available preoperatively are needed to improve the ability to recognize likelihood of upgrading in patients with low-risk PC.

METHODS

More than 30 clinicopathologic parameters were assessed in consecutive patients with Gleason 6 PC upon biopsy who underwent radical prostatectomy. A nomogram for predicting upgrading (Gleason ≥ 7) on final pathology was generated using multivariable logistic regression in a development cohort of 431 patients. External validation was performed in 2 separate cohorts consisting of 1151 patients and 392 patients. Nomogram performance was assessed using receiver operating characteristic curves, calibration, and decision analysis.

RESULTS

On multivariable analysis, variables predicting upgrading were prostate-specific antigen density using ultrasound (odds ratio [OR] = 229, P = .003), obesity (OR = 1.90, P = .05), number of positive cores (OR = 1.23, P = .01), and maximum core involvement (OR = 0.02, P = .01). On internal validation, the bootstrap-corrected predictive accuracy was 0.753. External validation revealed a predictive accuracy of 0.677 and 0.672. The nomogram demonstrated excellent calibration in all 3 cohorts and decision curves demonstrated high net benefit across a wide range of threshold probabilities. The nomogram demonstrated areas under the curve of 0.597 to 0.672 for predicting upgrading in subsets of men with very low-risk PC who meet active surveillance criteria (all P < .001), allowing further risk stratification of these individuals.

CONCLUSIONS

A nomogram was developed and externally validated that uses preoperative clinical parameters and biopsy findings to predict the risk of pathological upgrading in Gleason 6 patients. This can be used to further inform patients with lower risk PC who are considering treatment or active surveillance.