Risk stratification of men choosing surveillance for low risk prostate cancer

The association between patient and disease characteristics, and the risk of disease progression in patients with prostate cancer on active surveillance

PURPOSE

The objective of this study was to identify and assess patient and disease characteristics associated with an increased risk of disease progression in men with prostate cancer on active surveillance.

METHODS

We studied patients with low-risk (ISUP GG1) or favorable intermediate-risk (ISUP GG2) PCa. All patients had at least one repeat biopsy. Disease progression was the primary outcome of this study, based on pathological upgrading. Univariate and multivariate Cox proportional hazard analyses were used to evaluate the association between covariates and disease progression.

RESULTS

In total, 240 men were included, of whom 198 (82.5%) were diagnosed with low-risk PCa and 42 (17.5%) with favorable intermediate-risk PCa. Disease progression was observed in 42.9% (103/240) of men. Index lesion > 10 mm (HR = 2.85; 95% CI 1.74-4.68; p < 0.001), MRI (m)T-stage 2b/2c (HR = 2.52; 95% CI 1.16-5.50; p = 0.02), highest PI-RADS score of 5 (HR 3.05; 95% CI 1.48-6.28; p = 0.002) and a higher PSA level (HR 1.06; 95% CI 1.01-1.11; p = 0.014) at baseline were associated with disease progression on univariate analysis. Multivariate analysis showed no significant baseline predictors of disease progression.

CONCLUSION

In AS patients with low-risk or favorable intermediate-risk PCa, diameter of index lesion, MRI (m)T-stage, height of the PI-RADS score and the PSA level at baseline are significant predictors of disease progression to first repeat biopsy.

Clinical and histological predictive factors of reclassification of prostate cancer patients on active surveillance

INTRODUCTION AND OBJECTIVE

Active surveillance (AS) has been established as a therapeutic strategy in patients with low-risk prostate cancer. Demographic and anatomopathological factors that increase the probability of reclassifying patients have been identified.

MATERIALS AND METHODS

Laboratory and histopathological data were collected from 116 patients included on AS since 2014. Univariate analysis was performed with Chi-square, t-student and Kendall's Tau, multivariate analysis according to logistic regression and Kaplan-Meier curves were calculated.

RESULTS

Of the 116 patients in AS, the median age at diagnosis was 66 years and the median follow-up was 13 months (2-72). Of these, 61 (52.6%) are still on surveillance, while 55 (47.4%) have left the program, mostly due to histological progression (52 patients (45.2%)); radical prostatectomy was performed in 27 (49.1%). Prostate volume (PV)≤60cc and the number of positive cylinders >1 in diagnostic biopsy (P=.05) were associated with higher reclassification rate in univariate analysis (P<.05). Multivariate analysis showed that these two variables significantly correlated with higher reclassification rate (PV 60 cc: OR 4.39, P=.04; >1 positive cylinder at diagnostic biopsy: OR 2.48, P=.03).

CONCLUSIONS

It has been shown that initial ultrasound volume and the number of positive cylinders in the diagnostic biopsy are independent risk factors for reclassification. Initial PSA, laterality of the affected cylinders and PSA density were not predictive factors of progression in our series.

Correlation of the Grade Group of Prostate Cancer according to the International Society of Urological Pathology (Isup) 2014 Classification between Prostate Biopsy and Radical Prostatectomy Specimens

ABTRACTWe aimed to assess the correlation between ISUP 2014 grades of needle biopsy (NB) and radical prostatectomy (RP) specimens and the parameters effecting this correlation. A total of 353 patients, who underwent a radical prostatectomy with diagnose of prostate cancer, were included in the study. Especially, the maximum percentage of core involved by cancer (MPCI) of upgraded group was significantly higher than those of correlated group and downgraded group. MPCI might be used as a preoperative value to determine risk classification and to help counsel patients with regard to treatment decision and prognosis of disease.

Active Surveillance-Is It Feasible for Intermediate-risk Localised Prostate Cancer?

Background

Although active surveillance (AS) is a well-recognised treatment option for localised low-risk prostate cancer (LRPC), its role in the management of localised intermediate-risk prostate cancer (IRPC) is not clear yet and the available literature is slightly contradictory.

Objective

To compare the outcome of AS between LRPC and IRPC patients.

Design, setting, and participants

Between November 2002 and August 2019, 372 men with localised prostate cancer (PC) underwent AS in our hospital based on local departmental protocol.

Outcome measurements and statistical analysis

The primary outcome measures were overall survival, disease progression–free survival, treatment-free survival, and biochemical recurrence–free survival. Survival times in the low- and intermediate-risk groups were compared using Cox regression analysis.

Results and limitations

Out of 372 localised PC patients, 276 (74%) had LRPC and 96 (26%) IRPC. Overall, 86 (31.2%) low-risk and 25 (26%) intermediate-risk patients developed disease progression, and 86 (31.2%) low-risk and 22 (23%) intermediate-risk patients underwent active treatment. Among the treated patients, eight (2.9%) LRPC patients and one (1%) IRPC patient developed biochemical recurrence. In total, only one patient (from the low-risk group) had metastasis and 25 patients passed away (18 from the low-risk and seven from the intermediate-risk group). No death was recorded due to PC in the cohort. There was no difference in any of the survival outcomes between LRPC and IRPC patients in unadjusted analysis as well as when analysis was performed after adjusting the potentially confounding factors. Limitations include relatively short median follow-up time and failure to objectively define the criteria for the selection of IRPC patients suitable for AS.

Conclusions

The option of AS could be considered for carefully selected and well-informed patients with IRPC provided close structured monitoring is maintained.

Patient summary

In this report, we looked at various survival outcomes of active surveillance between low- and intermediate-risk prostate cancer patients in a large British population. There was no difference in any of the survival outcomes between the two groups. We concluded that carefully selected intermediate-risk prostate cancer patients could be offed the option of active surveillance.

Multiparametric magnetic resonance imaging facilitates reclassification during active surveillance for prostate cancer

OBJECTIVE

To investigate the utility of multiparametric magnetic resonance imaging (mpMRI) in the reassessment and monitoring of patients on active surveillance (AS) for Grade Group (GG) 1 prostate cancer (PCa).

PATIENTS AND METHODS

We identified, from our prospectively maintained institutional review board-approved database, 181 consecutive men enrolled on AS for GG 1 PCa who underwent at least one surveillance mpMRI followed by MRI/prostate biopsy (PBx). A subset analysis was performed among 68 patients who underwent serial (at least two) mpMRI/PBx during AS. Pathological progression (PP) was defined as upgrade to GG ≥2 on follow up biopsy.

RESULTS

Baseline MRI was performed in 34 patients (19%). At a median follow-up of 2.2 years for the overall cohort, the PP was 12% (6/49) for Prostate Imaging Reporting and Data System (PI-RADS) 1-2 lesions and 37% (48/129) for the PI-RADS ≥3 lesions. The 2-year PP-free survival rate was 84%. Surveillance prostate-specific antigen density (P < 0.001) and surveillance PI-RADS ≥3 (P = 0.002) were independent predictors of PP on reassessment MRI/PBx. In the serial MRI cohort, the 2-year PP-free survival was 95% for the No-MRI-progression group vs 85% for the MRI-progression group (P = 0.02). MRI progression was significantly higher in the PP (62%) than in the No-PP (31%) group (P = 0.04). If serial MRI were used for PCa surveillance and biopsy were triggered based only on MRI progression, 63% of PBx might be postponed at the cost of missing 12% of GG ≥2 PCa in those with stable MRI. Conversely, this strategy would miss 38% of those with upgrading to GG ≥2 PCa on biopsy. Stable serial mpMRI correlates with no reclassification to GG ≥3 PCa during AS.

CONCLUSION

On surveillance mpMRI, PI-RADS ≥3 was associated with increased risk of PCa reclassification. Surveillance biopsy based only on MRI progression may avoid a large number of biopsies at the cost of missing many PCa reclassifications.

How to Pick Out the "Unreal" Gleason 3 + 3 Patients: A Nomogram for More Precise Active Surveillance Protocol in Low-Risk Prostate Cancer in a Chinese Population

OBJECTIVE

To develop a nomogram for selecting the "unreal" Gleason score (GS) 3 + 3 patients in biopsy GS 3 + 3 prostate cancer (PCa) patients.

METHODS

Patients who were newly diagnosed with PCa by biopsy and underwent radical prostatectomy in the First Affiliated Hospital of Nanjing Medical University from January 2009 to October 2018 were enrolled. Comparisons were made between GS 3 + 3 and higher grade PCa patients. Logistic regression analysis was performed to determine the risk factors for the "unreal" GS 3 + 3 PCa in biopsy GS 3 + 3 patients. Then, a nomogram was developed to predict the probability of "unreal" GS 3 + 3 PCa according to the results of multivariate analysis. Finally, receiver operating characteristic and decision curve analysis (DCA) curves were structured to identify the efficiency of the predictive model.

RESULTS

Compared to higher GS grade, biopsy GS 3 + 3 had greater upgrade risk (P < 0.05) while a lower proportion of positive surgical margins, seminal vesicle invasion, extra-prostatic extension, lymph node invasion, and nerve invasion (all P < 0.05). Multivariate analysis showed that age, PSAD, prostate imaging reporting and data system (PI-RADS) score and biopsy positive cores were significant risk factors for "unreal" GS 3 + 3. A nomogram was developed utilizing these factors with high prediction performance (area under curve = 0.924). Furthermore, DCA curve suggested that this predictive model was effective.

CONCLUSIONS

The nomogram identified the probability of "unreal" GS 3 + 3 PCa in biopsy GS 3 + 3 PCa patients, which was of great value for clinical guidance in low risk PCa therapy.

Role of Surveillance Biopsy with No Cancer as a Prognostic Marker for Reclassification: Results from the Canary Prostate Active Surveillance Study

BACKGROUND

Many patients who are on active surveillance (AS) for prostate cancer will have surveillance prostate needle biopsies (PNBs) without any cancer evident.

OBJECTIVE

To define the association between negative surveillance PNBs and risk of reclassification on AS.

DESIGN, SETTING, AND PARTICIPANTS

All men were enrolled in the Canary Prostate Active Surveillance Study (PASS) between 2008 and 2016. Men were included if they had Gleason ≤3+4 prostate cancer and <34% core involvement ratio at diagnosis. Men were prescribed surveillance PNBs at 12 and 24 mo after diagnosis and then every 24 mo.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Reclassification was defined as an increase in Gleason grade and/or an increase in the ratio of biopsy cores to cancer to ≥34%. PNB outcomes were defined as follows: (1) no cancer on biopsy, (2) cancer without reclassification, or (3) reclassification. Kaplan-Meier and Cox proportional hazard models were performed to assess the risk of reclassification.

RESULTS AND LIMITATIONS

A total of 657 men met inclusion criteria. On first surveillance PNB, 214 (32%) had no cancer, 282 (43%) had cancer but no reclassification, and 161 (25%) reclassified. Among those who did not reclassify, 313 had a second PNB. On second PNB, 120 (38%) had no cancer, 139 (44%) had cancer but no reclassification, and 54 (17%) reclassified. In a multivariable analysis, significant predictors of decreased future reclassification after the first PNB were no cancer on PNB (hazard ratio [HR]=0.50, p=0.008), lower serum prostate-specific antigen, larger prostate size, and lower body mass index. A finding of no cancer on the second PNB was also associated with significantly decreased future reclassification in a multivariable analysis (HR=0.15, p=0.003), regardless of the first PNB result. The major limitation of this study is a relatively small number of patients with long-term follow-up.

CONCLUSIONS

Men who have a surveillance PNB with no evidence of cancer are significantly less likely to reclassify on AS in the PASS cohort. These findings have implications for tailoring AS protocols.

PATIENT SUMMARY

Men on active surveillance for prostate cancer who have a biopsy showing no cancer are at a decreased risk of having worse disease in the future. This may have an impact on how frequently biopsies are required to be performed in the future.

Prostate Biopsy in Active Surveillance Protocols: Immediate Re-biopsy and Timing of Subsequent Biopsies

PURPOSE OF REVIEW

This manuscript reviews contemporary literature regarding prostate cancer active surveillance (AS) protocols as well as other tools that may guide the management of biopsy frequency and assess the possibility of progression in low-risk prostate cancer.

RECENT FINDINGS

There is no consensus regarding the timing of surveillance biopsies; however, an immediate repeat biopsy within 12 months of diagnosis for patients considering AS confirms patients who have favorable risk disease yet also identifies patients who were undersampled initially. Studies regarding multiparametric MRI, nomograms, and biomarkers show promise in risk stratifying and counseling patients during AS. Further studies are needed to determine if these supplemental tests can decrease the frequency of surveillance biopsies. An immediate re-biopsy can help to reduce the risk of missing clinically significant disease. Other clinical tools, including mpMRI, exist that can be used as an adjunct to counsel patients and guide a personalized discussion regarding the frequency of surveillance biopsies.

Biomarkers in active surveillance

The use of active surveillance (AS) is increasing for favorable-risk prostate cancer. However, there remain challenges in patient selection for AS, due to the limitations of current clinical staging. In addition, monitoring protocols relying on serial biopsies is invasive and presents risks such as infection. For these reasons, there is substantial interest in identifying markers that can be used to improve AS selection and monitoring. In this article, we review the evidence on serum, urine and tissue markers in AS.

Prognostic Significance of a Negative Confirmatory Biopsy on Reclassification Among Men on Active Surveillance

OBJECTIVE

To examine the association between absence of disease on confirmatory biopsy and risk of pathologic reclassification in men on active surveillance (AS).

MATERIALS AND METHODS

Men with grade groups 1 and 2 disease on AS between 2002 and 2015 were identified who received a confirmatory biopsy within 1 year of diagnosis and ≥3 biopsies overall. The primary outcomes were pathologic reclassification by grade (any increase in primary Gleason pattern or Gleason score) or volume (>33% of sampled cores involved or increase in the number of cores with >50% involvement). The effect of a negative confirmatory biopsy survival was evaluated using Kaplan-Meier analysis and a Cox proportional hazards modeling.

RESULTS

Out of 635 men, 224 met inclusion criteria (median follow-up: 55.8 months). A total of 111 men (49.6%) had a negative confirmatory biopsy. Decreased grade reclassification (69.7% vs 83.9%; P = .01) and volume reclassification (66.3% vs 87.4%; P = .004) was seen at 5 years for men with a negative confirmatory biopsy compared with those with a positive biopsy. On adjusted analysis, a negative confirmatory biopsy was associated with a decreased risk of grade reclassification (hazard ratio, 0.51; 95% confidence interval, 0.28-0.94; P = .03) and volume reclassification (hazard ratio, 0.32; 95% confidence interval, 0.17-0.61; P = .0006) at a median of 4.7 years.

CONCLUSION

Absence of cancer on the confirmatory biopsy is associated with a significant decrease in rate of grade and volume reclassification among men on AS. This information may be used to better counsel men on AS.

Diffusion weighted imaging of the prostate-principles, application, and advances

This review article aims to provide an overview on the principles of diffusion-weighted magnetic resonance imaging (DW-MRI) and its applications in the imaging of the prostate. DW-MRI with regards to different applications for prostate cancer (PCa) detection and characterization, local staging as well as for active surveillance (AS) and tumor recurrence after radical prostatectomy (RP) will be discussed. Furthermore, advances in DW-MRI techniques like diffusion kurtosis imaging (DKI) will be presented.

Automated analysis of co-localized protein expression in histologic sections of prostate cancer

An automated approach based on routinely-processed, whole-slide immunohistochemistry (IHC) was implemented to study co-localized protein expression in tissue samples. Expression of two markers was chosen to represent stromal (CD31) and epithelial (Ki-67) compartments in prostate cancer. IHC was performed on whole-slide sections representing low-, intermediate-, and high-grade disease from 15 patients. The automated workflow was developed using a training set of regions-of-interest in sequential tissue sections. Protein expression was studied on digital representations of IHC images across entire slides representing formalin-fixed paraffin embedded blocks. Using the training-set, the known association between Ki-67 and Gleason grade was confirmed. CD31 expression was more heterogeneous across samples and remained invariant with grade in this cohort. Interestingly, the Ki-67/CD31 ratio was significantly increased in high (Gleason ≥ 8) versus low/intermediate (Gleason ≤7) samples when assessed in the training-set and the whole-tissue block images. Further, the feasibility of the automated approach to process Tissue Microarray (TMA) samples in high throughput was evaluated. This work establishes an initial framework for automated analysis of co-localized protein expression and distribution in high-resolution digital microscopy images based on standard IHC techniques. Applied to a larger sample population, the approach may help to elucidate the biologic basis for the Gleason grade, which is the strongest, single factor distinguishing clinically aggressive from indolent prostate cancer.

Prostate-specific antigen density is predictive of outcome in suboptimal prostate seed brachytherapy

PURPOSE

In prostate seed brachytherapy, a D₉₀ of <130 Gy is an accepted predictive factor for biochemical failure (BF). We studied whether there is a subpopulation that does not need additional treatment after a suboptimal permanent seed brachytherapy implantation.

METHODS AND MATERIALS

A total of 486 patients who had either BF or a minimum followup of 48 months without BF were identified. BF was defined according to the Phoenix definition (nadir prostate-specific antigen + 2). Univariate and multivariate analyses were performed, adjusting for known prognostic factors such as D₉₀ and prostate-specific antigen density (PSAD) of ≥0.15 ng/mL/cm³, to evaluate their ability to predict BF.

RESULTS

Median followup for patients without BF was 72 months (interquartile range 56-96). BF-free recurrence rate at 5 years was 95% and at 8 years 88%. In univariate analysis, PSAD and cancer of the prostate risk assessment score were predictive of BF. On multivariate analysis, none of the factors remained significant. The best prognosis had patients with a low PSAD (<0.15 ng/mL/cm³) and an optimal implant at 30 days after implantation (as defined by D₉₀ ≥ 130 Gy) compared to patients with both factors unfavorable (p = 0.006). A favorable PSAD was associate with a good prognosis, independently of the D₉₀ (<130 Gy vs. ≥130 Gy, p = 0.7).

CONCLUSIONS

Patients with a PSAD of <0.15 ng/mL/cm³ have little risk of BF, even in the case of a suboptimal implant. These results need to be validated in other patients' cohorts.

Prostate-specific antigen density as a parameter for the prediction of positive lymph nodes at radical prostatectomy

Objective:

The aim was to determine the prognostic ability of Partin's tables for a patient collective undergoing radical prostatectomy (RP) and to evaluate the association of prostate-specific antigen (PSA) density (PSAD) and postoperative lymph node status.

Methods:

From 1999 to 2006, 393 consecutive patients underwent RP at our Urology department. Patients with Gleason scores < 6, clinical stages >T2c or neoadjuvant hormonal therapy were excluded. Preoperative PSA, biopsy results, digital rectal examination, and prostate size at transrectal ultrasound were recorded. Risk stratification according to the Partin scoring system was performed. Postoperative results were compared with preoperative risk estimation. Univariate and multivariate statistical analysis about prediction of postoperative lymph node status was performed.

Results:

Lymph node invasion (LNI) was found in 36 patients (9.16%). Kendall's rank correlation analysis revealed a significant association between the number of removed LN and LNI (P = 0.016). Patients with LNI had a significantly higher preoperative PSA and PSAD. Preoperative Gleason score was a significant predictor of LNI. The Partin tables' prediction of organ confined stages, extraprostatic extension, and seminal vesicle invasion was in line with the pathological findings in our collective. PSAD was a significant predictor of LNI in univariate and multivariate analysis.

Conclusion:

The most widely used nomogram is of high value in therapy decision-making, although it remains an auxiliary means. Considering the performance of lymph node dissection, surgeons should be aware of the specifics of the applied nomogram. PSAD appears as a useful adjunctive parameter for preoperative prostate risk estimation and warrants further evaluation.

Active surveillance for prostate cancer: when to recommend delayed intervention

There are no agreed upon guidelines for placing patients on active surveillance (AS). Therefore, there are no absolute criteria for taking patients off AS and when to recommend treatment. The criteria used to define progression are currently based on prostate specific antigen (PSA) kinetics, biopsy reclassification, and change in clinical stage. Multiple studies have evaluated predictors of progression such as PSA, PSA density (PSAD), prostate volume, core positivity, and visible lesion on multiparametric magnetic resonance imaging (mpMRI). Furthermore, published nomograms designed to predict indolent prostate cancer do not perform well when used to predict progression. Newer biomarkers have also not performed well to predict progression. These findings highlight that clinical and pathologic variables are not enough to identify patients that will progress while on AS. In the future, with the use of imaging, biomarkers, and gene expression assays, we should be better equipped to diagnose/stage prostate cancer and to distinguish between insignificant and significant disease.

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.

Multiparametric magnetic resonance imaging-targeted biopsy for the detection of prostate cancer in patients with prior negative biopsy results

PURPOSE

We aimed to determine the performance of multiparametric magnetic resonance imaging (mpMRI) in the detection of prostate cancer (PCa) in patients with prior negative transrectal ultrasound-guided prostate biopsy (TRUS-B) results.

MATERIALS AND METHODS

Between 2010 and 2013, 2,416 men underwent TRUS-B or an mpMRI or both at Vancouver General Hospital. Among these, 283 men had persistent suspicion of PCa despite prior negative TRUS-B finding. An MRI was obtained in 112, and a lesion (prostate imaging reporting and data system score ≥ 3) was identified in 88 cases (78%). A subsequent combined MRI-targeted and standard template biopsy was performed in 86 cases. A matching cohort of 86 patients was selected using a one-nearest neighbor method without replacement. The end points were the rate of diagnosis of PCa and significant PCa (sPCa) (Gleason > 6, or > 2 cores, or > 50% of any core).

RESULTS

MRI-targeted TRUS-B detected PCa and sPCa in 36 (41.9%) and 30 (34.9%) men when compared with 19 (22.1%) and 14 (16.3%), respectively, men without mpMRI (P = 0.005 for both). In 9 cases (10.4%), MRI-targeted TRUS-B detected sPCa that was missed on standard cores. sPCa was present in 6 cases (6.9%) on standard cores but not the targeted cores. Multivariate analysis revealed that prostate imaging reporting and data system score and prostate-specific antigen density > 0.15 ng/ml(2) were statistically significant predictors of significant cancer detection (odds ratio = 14.93, P < 0.001 and odds ratio = 6.19, P = 0.02, respectively).

CONCLUSION

In patients with prior negative TRUS-B finding, MRI-targeted TRUS-B improves the detection rate of all PCa and sPCa.

Gleason Upgrading with Time in a Large Prostate Cancer Active Surveillance Cohort

PURPOSE

We report the percentage of patients on active surveillance who had disease pathologically upgraded and factors that predict for upgrading on surveillance biopsies.

MATERIALS AND METHODS

Patients in our active surveillance database with at least 1 repeat prostate biopsy were included. Histological upgrading was defined as any increase in primary or secondary Gleason grade on repeat biopsy. Multivariate analysis was used to determine baseline and dynamic factors associated with Gleason upgrading. This information was used to develop a nomogram to predict for upgrading or treatment in patients electing for active surveillance.

RESULTS

Of 862 patients in our cohort 592 had 2 or more biopsies. Median followup was 6.4 years. Of the patients 20% were intermediate risk, 0.3% were high risk and all others were low risk. During active surveillance 31.3% of cases were upgraded. On multivariate analysis clinical stage T2, higher prostate specific antigen and higher percentage of cores involved with disease at the time of diagnosis predicted for upgrading. A total of 27 cases (15% of those upgraded) were Gleason 8 or higher at upgrading, and 62% of all 114 upgraded cases went on to have active treatment. The nomogram incorporated clinical stage, age, prostate specific antigen, core positivity and Gleason score. The concordance index was 0.61.

CONCLUSIONS

In this large re-biopsy cohort with medium-term followup, most cases have not been pathologically upgraded to date. A model predicting for upgrading or radical treatment was developed which could be useful in counseling patients considering active surveillance for prostate cancer.

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.

The role of MRI in prostate cancer active surveillance

Prostate cancer is the most common cancer diagnosis in American men, excluding skin cancer. The clinical behavior of prostate cancer varies from low-grade, slow growing tumors to high-grade aggressive tumors that may ultimately progress to metastases and cause death. Given the high incidence of men diagnosed with prostate cancer, conservative treatment strategies such as active surveillance are critical in the management of prostate cancer to reduce therapeutic complications of radiation therapy or radical prostatectomy. In this review, we will review the role of multiparametric MRI in the selection and follow-up of patients on active surveillance.

Active surveillance for prostate cancer: a systematic review of clinicopathologic variables and biomarkers for risk stratification

CONTEXT

Active surveillance (AS) is an important strategy to reduce prostate cancer overtreatment. However, the optimal criteria for eligibility and predictors of progression while on AS are debated.

OBJECTIVE

To review primary data on markers, genetic factors, and risk stratification for patient selection and predictors of progression during AS.

EVIDENCE ACQUISITION

Electronic searches were conducted in PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to April 2014 for original articles on biomarkers and risk stratification for AS.

EVIDENCE SYNTHESIS

Patient factors associated with AS outcomes in some studies include age, race, and family history. Multiple studies provide consistent evidence that a lower percentage of free prostate-specific antigen (PSA), a higher Prostate Health Index (PHI), a higher PSA density (PSAD), and greater biopsy core involvement at baseline predict a greater risk of progression. During follow-up, serial measurements of PHI and PSAD, as well as repeat biopsy results, predict later biopsy progression. While some studies have suggested a univariate relationship between urinary prostate cancer antigen 3 (PCA3) and transmembrane protease, serine 2-v-ets avian erythroblastosis virus E26 oncogene homolog gene fusion (TMPRSS2:ERG) with adverse biopsy features, these markers have not been consistently shown to independently predict AS outcomes. No conclusive data support the use of genetic tests in AS. Limitations of these studies include heterogeneous definitions of progression and limited follow-up.

CONCLUSIONS

There is a growing body of literature on patient characteristics, biopsy features, and biomarkers with potential utility in AS. More data are needed on practical applications such as combining these tests into multivariable clinical algorithms and long-term outcomes to further improve AS in the future.

PATIENT SUMMARY

Several PSA-based tests (free PSA, PHI, PSAD) and the extent of cancer on biopsy can help to stratify the risk of progression during active surveillance. Investigation of several other markers is under way.

Reclassification rates are higher among African American men than Caucasians on active surveillance

OBJECTIVE

To evaluate the risk of reclassification on serial biopsy for Caucasian and African American (AA) men with very low-risk (VLR) prostate cancer enrolled in a large prospective active surveillance (AS) registry.

METHODS

The Johns Hopkins AS registry is a prospective observational study that has enrolled 982 men since 1994. Including only men who met all National Comprehensive Cancer Network VLR criteria (clinical stage ≤T1, Gleason score ≤6, prostate-specific antigen [PSA] level <10 ng/mL, PSA density <0.15 ng/mL/cm(3), positive cores <3, percent cancer per core ≤50), we analyzed a cohort of 654 men (615 Caucasians and 39 AAs). The association of race with reclassification on serial biopsy was assessed with competing-risks regressions.

RESULTS

AA men on AS were more likely than Caucasians to experience upgrading on serial biopsy (36% vs 16%; adjusted P <.001). Adjusting for PSA level, prostate size, volume of cancer on biopsy, treatment year, and body mass index, AA race was an independent predictor of biopsy reclassification (subdistribution hazard ratio, 1.8; P = .003). Examining specific modes of reclassification, AA race was independently associated with reclassification by grade (subdistribution hazard ratio, 3.0; P = .002) but not by volume.

CONCLUSION

AA men with VLR prostate cancer followed on AS are at significantly higher risk of grade reclassification compared with Caucasians. Therefore, if the goal of AS is to selectively monitor men with low-grade disease, AA men may require alternate selection criteria.

Extended followup and risk factors for disease reclassification in a large active surveillance cohort for localized prostate cancer

PURPOSE

Active surveillance to manage prostate cancer provides an alternative to immediate treatment in men with low risk prostate cancer. We report updated outcomes from a long-standing active surveillance cohort and factors associated with reclassification.

MATERIALS AND METHODS

We retrospectively reviewed data on all men enrolled in the active surveillance cohort at our institution with at least 6 months of followup between 1990 and 2013. Surveillance consisted of quarterly prostate specific antigen testing, repeat imaging with transrectal ultrasound at provider discretion and periodic repeat prostate biopsies. Factors associated with repeat biopsy reclassification and local treatment were determined by multivariate Cox proportional hazards regression. We also analyzed the association of prostate specific antigen density and outcomes stratified by prostate size.

RESULTS

A total of 810 men who consented to participate in the research cohort were followed on active surveillance for a median of 60 months. Of these men 556 (69%) met strict criteria for active surveillance. Five-year overall survival was 98%, treatment-free survival was 60% and biopsy reclassification-free survival was 40%. There were no prostate cancer related deaths. On multivariate analysis prostate specific antigen density was positively associated with the risk of biopsy reclassification and treatment while the number of biopsies and time between biopsies were inversely associated with the 2 outcomes (each p <0.01). When stratified by prostate volume, prostate specific antigen density remained significantly associated with biopsy reclassification for all strata but prostate specific antigen density was only significantly associated with treatment in men with a smaller prostate.

CONCLUSIONS

Significant prostate cancer related morbidity and mortality remained rare at intermediate followup. Prostate specific antigen density was independently associated with biopsy reclassification and treatment while on active surveillance.

The Prognostic Value of Percentage of Positive Biopsy Cores, Percentage of Cancer Volume, and Maximum Involvement of Biopsy Cores in Prostate Cancer Patients Receiving Proton and Photon Beam Therapy

The purpose of the study is to compare the prognostic value of percentage of positive biopsy cores (PPBC), percentage of cancer volume (PCV), and maximum involvement of biopsy cores (MIBC) as a prognostic factor in low- and intermediate-risk patients with clinically localized prostate cancer who received proton or photon beam therapy. Four hundred and fifty-nine patients with clinically localized prostate carcinoma who were treated with proton or photon beam therapy at Loma Linda University Medical Center were used for this analysis. Patients were treated with a median dose of 74.0 Gy (range 70.2–79.2) proton or combined proton/photon beam radiotherapy. Pathology reports were reviewed and PPBC, PCV, and MIBC were recorded. Analysis of biochemical no evidence of disease (bNED) outcome was assessed using Kaplan-Meier analyses. Cox regression multivariate analyses were performed to assess the impact of the biopsy factors on survival. Results: 285, 291, and 291 patients had biopsy information available for analysis, respectively. Survival analysis showed that a higher PPBC, PCV, and MIBC were each individually associated with an increased risk of biochemical failure on univariate analysis ( p < 0.01). Only PPBC and PCV were associated with an increased risk of biochemical failure on multivariate analysis, adjusting for age, NCCN risk group, and dose ( p < 0.01). When isolating the intermediate-risk group, only PPBC and PCV were statistically significant on multivariate analysis. Multivariate analysis of the intermediate-risk group comparing PPBC and PCV showed that PPBC was not a significant predictor of biochemical failure, while PCV was a significant predictor of biochemical failure ( p = 0.37 and p = 0.03, respectively). Conclusion: PPBC and PCV can potentially be used for additional risk stratification of intermediate-risk patients with PCV potentially being the most clinically relevant predictor bNED survival. MIBC was not found to have utility in the prognosis of low- and intermediate-risk patients.

[The significance of PSA density as predictive factor in Afro-Caribbean patients eligible for active surveillance by the French protocol criteria]

OBJECTIVES

Study the interest of addition of PSA density (PSAD), to the selection criteria of the French protocol for inclusion patients Afro-Caribbean on active surveillance prostate cancer.

METHODS

A retrospective analysis of 1505 patients who had, in turn, a radical prostatectomy for cancer between 2000 and 2012, in a single reference center. One hundred and forty-one patients was eligible, at the time of their diagnosis, for active surveillance by the criteria of the French protocol. This population was divided into 2 groups according to the histological analysis of the prostatectomy specimen confirmed indolent cancer or overturned. The median PSAD of each group was calculated to be compared. Secondarily, the most discriminating PSAD was investigated by the method of ROC after constitution tables intrinsic validity in this population. This threshold has secondary conducting a comparative analysis of the underestimation of cancer in terms of aggressiveness and/or extension between patients selected according to the criteria of the French protocol and "on-selected" patients according to these criteria and their PSAD.

RESULTS

Of the 141 patients identified for analysis, histological examination of the prostatectomy specimen has to show that 42 patients (29.7 %) were actually more aggressive cancer (20.6 % of Gleason ≥ 7), wider (4.2 % ≥ pT3) or larger and more aggressive (4.9 %) than foreshadowed criteria French protocol. The median PSAD these 42 patients were significantly higher than the median PSAD patients correctly estimated (0.18 vs. 0.14, p-value=0.046). The application of the most discriminating threshold: 0.15 ng/ml/cm(3) in this population allowed to significantly improve the selection of candidates of the 79 "on-selected" patients, six (20.2 %) were actually more aggressive cancer (13.9 % of Gleason ≥ 7), wider (2.5 % ≥ pT3) or larger and more aggressive (3.8 %).

CONCLUSION

The criteria for the French protocol for active surveillance, applied to the Caribbean population underestimate 29 % of non-latent cancers. Adjuvants criteria that must be inexpensive, sensitive and specific seem necessary in this population. A PSAD<0.15 ng/ml/cm(3) could be one of these criteria.

Kallikreins as biomarkers for prostate cancer

The introduction of testing for prostate-specific antigen (PSA), a member of the fifteen-gene family of kallikrein-related peptidases and also known as kallikrein-related peptidase 3 (KLK3), in blood has revolutionized both the detection and management of prostate cancer. Given the similarities between PSA and other KLK gene family members along with limitations of PSA as a biomarker for prostate cancer mainly in reference to diagnostic specificity, the potential roles of other members of this gene family as well as PSA derivatives and isoforms in the management of prostate cancer have been studied extensively. Of these, approaches to measure distinct molecular forms of PSA (free, intact, complexed PSA, and pro-PSA) combined with kallikrein-related peptidase 2 (KLK2), also known as hK2, have been considered holding particular promise in enhancing the diagnosis of prostate cancer. Recently, an integrated approach of applying a panel of four kallikrein markers has been demonstrated to enhance accuracy in predicting the risk of prostate cancer at biopsy. This review presents an overview of kallikreins, starting with the past and current status of PSA, summarizing published data on the evaluations of various KLKs as biomarkers in the diagnosis, prognostication, and monitoring of prostate cancer.

Role of multiparametric 3.0-Tesla magnetic resonance imaging in patients with prostate cancer eligible for active surveillance

OBJECTIVE

To evaluate predictors of more aggressive disease and the role of multiparametric 3.0-T magnetic resonance imaging (MRI) in selecting patients with prostate cancer for active surveillance (AS).

PATIENTS AND METHODS

We retrospectively assessed 298 patients with prostate cancer who met the Prostate Cancer Research International: Active Surveillance (PRIAS) criteria, defined as T1c/T2, PSA level of ≤10 ng/mL, PSA density (PSAD) of <0.2 ng/mL(2) , Gleason score <7, and one or two positive biopsy cores. All patients underwent preoperative MRI, including T2-weighted, diffusion-weighted, and dynamic contrast-enhanced imaging, as well as radical prostatectomy (RP) between June 2005 and December 2011. Imaging results were correlated with pathological findings to evaluate the ability of MRI to select patients for AS.

RESULTS

In 35 (11.7%) patients, no discrete cancer was visible on MRI, while in the remaining 263 (88.3%) patients, a discrete cancer was visible. Pathological examination of RP specimens resulted in upstaging (>T2) in 21 (7%) patients, upgrading (Gleason score >6) in 136 (45.6%), and a diagnosis of unfavourable disease in 142 (47.7%) patients. The 263 patients (88.3%) with visible cancer on imaging were more likely to have their cancer status upgraded (49.8% vs 14.3%) and be diagnosed with unfavourable disease (52.1% vs 14.3%) than the 35 patients (11.7%) with no cancer visible upon imaging, and these differences were statistically significant (P < 0.001 for all). A visible cancer lesion on MRI, PSAD, and patient age were found to be predictors of unfavourable disease in multivariate analysis.

CONCLUSION

MRI can predict adverse pathological features and be used to assess the eligibility of patients with prostate cancer for AS.

Modeling grade progression in an active surveillance study

Prostate cancer grade, assessed with the Gleason score, describes how abnormal the tumor tissue and cells appear, and it is an important prognostic indicator of disease progression. Whether prostate tumors change grade is a question that has implications for screening and treatment. Empirical data on tumor grade over time have become available from men biopsied regularly as part of active surveillance (AS). However, biopsy (BX) grade is subject to misclassification. In this article, we develop a model that allows for estimation of the time of grade change while accounting for the misclassification error from BX grade. We use misclassification rates from studies of prostate cancer BXs followed by radical prostatectomy. Estimation of the transition times from true low-grade to high-grade disease is conducted within a Bayesian framework. We apply our model to serial observations on BX grade among 627 cases enrolled in a cohort of AS patients at Johns Hopkins University who were biopsied annually and referred to treatment if there was any evidence of disease progression on BX. We consider different prior distributions for the time to true grade progression. The estimated likelihood of grade progression within 10 years of study entry ranges from 12% to 24% depending on the prior. We conclude that knowledge of rates of grade misclassification allows for determination of true grade progression rates among men with serial BXs on AS. Although our results are sensitive to prior specifications, they indicate that in a nontrivial fraction of the patient population, tumor grade can progress.

Prostate specific antigen velocity risk count predicts biopsy reclassification for men with very low risk prostate cancer

PURPOSE

Prostate specific antigen velocity is an unreliable predictor of adverse pathology findings in patients on active surveillance for low risk prostate cancer. However, to our knowledge a new concept called prostate specific antigen velocity risk count, recently validated in a screening cohort, has not been investigated in an active surveillance cohort.

MATERIALS AND METHODS

We evaluated a cohort of men from 1995 to 2012 with prostate cancer on active surveillance. They had stage T1c disease, prostate specific antigen density less than 0.15 ng/ml, Gleason score 6 or less, 2 or fewer biopsy cores and 50% or less involvement of any core with cancer. The men were observed by semiannual prostate specific antigen measurements, digital rectal examinations and an annual surveillance biopsy. Treatment was recommended for biopsy reclassification. Patients with 30 months or greater of followup and 3 serial prostate specific antigen velocity measurements were used in primary analysis by logistic regression, Cox proportional hazards, Kaplan-Meier analysis and performance parameters, including the AUC of the ROC curve.

RESULTS

Primary analysis included 275 of 668 men who met very low risk inclusion criteria, of whom 83 (30.2%) were reclassified at a median of 57.1 months. Reclassification risk increased with risk count, that is a risk count of 3 (HR 4.63, 95% CI 1.54-13.87) and 2 (HR 3.73, 95% CI 1.75-7.97) compared to zero. Results were similar for Gleason score reclassification (HR 7.45, 95% CI 1.60-34.71 and 3.96, 95% CI 1.35-11.62, respectively). On secondary analysis the negative predictive value (risk count 1 or less) was 91.5% for reclassification in the next year. Adding the prostate specific antigen velocity risk count improved the AUC in a model including baseline prostate specific antigen density (0.7423 vs 0.6818, p = 0.025) and it outperformed the addition of overall prostate specific antigen velocity (0.7423 vs 0.6960, p = 0.037).

CONCLUSIONS

Prostate specific antigen velocity risk count may be useful for monitoring patients on active surveillance and decreasing the frequency of biopsies needed in the long term.

Active surveillance for prostate cancer: an underutilized opportunity for reducing harm

The management of localized prostate cancer is controversial, and in the absence of comparative trials to inform best practice, choices are driven by personal beliefs with wide variation in practice patterns. Men with localized disease diagnosed today often undergo treatments that will not improve overall health outcomes, and active surveillance has emerged as one approach to reducing this overtreatment of prostate cancer. The selection of appropriate candidates for active surveillance should balance the risk of harm from prostate cancer without treatment, and a patient's personal preferences for living with a cancer and the potential side effects of curative treatments. Although limitations exist in assessing the potential for a given prostate cancer to cause harm, the most common metrics used today consider cancer stage, prostate biopsy features, and prostate-specific antigen level together with the risk of death from nonprostate causes based on age and overall state of health.

Serum prostate-specific antigen (PSA) concentration is positively associated with rate of disease reclassification on subsequent active surveillance prostate biopsy in men with low PSA density

OBJECTIVE

To investigate the association between serum prostate-specific antigen (PSA) concentration at active surveillance (AS) entry and disease reclassification on subsequent AS biopsy ('biopsy reclassification') in men with low PSA density (PSAD). To investigate whether a clinically meaningful PSA threshold for AS eligibility/ineligibility for men with low PSAD can be identified based on risk of subsequent biopsy reclassification.

PATIENTS AND METHODS

We included men enrolled in the Johns Hopkins AS Study (JHAS) who had a PSAD of <0.15 ng/mL/g (640 men). We estimated the incidence rates (IRs; per 100 person years) and hazard ratios (HR) of biopsy reclassification (Gleason score ≥ 7, any Gleason pattern 4 or 5, ≥3 positive cores, or ≥50% cancer involvement/biopsy core) for categories of serum PSA concentration at the time of entry into AS. We generated predicted IRs using Poisson regression to adjust for age and prostate volume, mean percentage free PSA (ratio of free to total PSA) and maximum percentage biopsy core involvement with cancer.

RESULTS

The unadjusted IRs (per 100 person years) of biopsy reclassification across serum PSA concentration at entry into JHAS showed, in general, an increase; however, the pattern was not linear with higher IRs in the group ≥ 4 to <6 ng/mL (14.2, 95% confidence interval [CI] 11.8-17.2%) when compared with ≥6 to <8 ng/mL (8.4, 95% CI 5.7-12.3%) but almost similar IRs when compared with the group ≥ 8 to <10 ng/mL (14.8, 95% CI 8.4-26.1%). The adjusted predicted IRs of reclassification showed a similar non-linear increase in IRs, whereby the rates around 4 ng/mL were similar to the rates around 10 ng/mL.

CONCLUSION

Risk for biopsy reclassification increased non-linearly across PSA concentration in men with low PSAD, whereby no obvious clinically meaningful threshold could be identified. This information could be incorporated into decision-making for AS. However, longer follow-up times are needed to warrant final conclusions.

Pathological outcomes of Japanese men eligible for active surveillance after radical prostatectomy

BACKGROUND

The aim of this study was to analyze the pathological features of prostatectomy specimens from patients with low-risk prostate cancer eligible for active surveillance (AS) and evaluate preoperative data suitable for predicting upstaged (≥pT3) or upgraded disease (Gleason score of ≥7), defined as 'reclassification'.

METHODS

A retrospective analysis of 521 consecutive radical prostatectomy procedures (January 2005 through to December 2011) performed at our institution without neoadjuvant hormonal therapy was performed. Eighty-four patients fulfilled the following criteria-clinical T1 or T2 disease, prostate-specific antigen (PSA) level of ≤10 ng/ml, one or two positive biopsies, and Gleason score of <7. Clinicopathological features at diagnosis were compared between patients with and without reclassification after radical prostatectomy.

RESULTS

Forty of 84 patients (47.6 %) had a Gleason score of ≥7, and 8 (9.5 %) had upstaged disease (≥pT3). Seven patients with upstaged disease also showed upgraded reclassification. Two patients with reclassification showed biochemical recurrence at 59 and 89 months after surgery, respectively. Preoperative parameters evaluated included age, PSA level, PSA density (PSAD), clinical T stage, and number and percentage of positive prostate cores. Among 82 patients with complete data, univariate analysis showed that PSAD (ng/ml(2)) was a significant parameter to discriminate patients with reclassified disease and those without reclassified disease (p < 0.001). Multivariate analysis revealed that PSAD was the only independent variable to predict disease with reclassification (p = 0.006).

CONCLUSIONS

Preoperative PSAD may be a good indicator for selecting patients eligible for AS in the Japanese population.

Improving risk stratification in patients with prostate cancer managed by active surveillance: a nomogram predicting the risk of biopsy progression

OBJECTIVE

To develop a clinical tool that integrates different risk factors and provides individual predictions of the risk of biopsy progression in patients with prostate cancer managed by active surveillance.

MATERIALS AND METHODS

Our analysis included 205 patients on active surveillance, each of whom had had at least two surveillance biopsies. We used the Cox proportional hazard regression model to analyse the association between different risk factors and progression-free survival over successive biopsies. This multivariate model was then used to develop a nomogram. Discrimination and calibration of the nomogram were internally validated using 200 bootstrap resamplings.

RESULTS

The median follow-up of patients free of progression was 4.6 years. A total of 58 (28%) patients experienced progression. Factors significantly associated with progression were: overall number of positive cores in the diagnostic and first surveillance biopsies, race and prostate-specific antigen density. The bootstrapping concordance index of the nomogram including these variables was 81%. The nomogram tended to underestimate the probability of progression but it identified fairly accurately the distinct groups of patients at low, intermediate and high risk of progression.

CONCLUSIONS

In the development cohort, the nomogram was able to separate patients with respect to their risk of biopsy progression. Since accurate risk stratification is essential to optimize patient care, this tool, if external validation confirms its performance, may prove useful for both the counselling and management of patients with low-volume, Gleason 6 prostate cancer.

Brachytherapy in Men with Prostate Cancer: Update on Indications and Outcomes

Brachytherapy (BT), using either a low-dose-rate (LDR) or mostly high-dose-rate (HDR) technique, is the device able to deliver the highest dose-rate in the most conformal way It is used as monotherapy or in combination with external beam radiotherapy (EBRT). LDR-BT is mostly used as monotherapy; HDR-BT is combined with EBRT +/– adjuvant hormone therapy In patients with low-risk disease and in selected intermediate-risk patients, LDR-BT ensures long-term good disease control rates and HDR-BT shows similar results, even if with shorter follow-up. In patients with intermediate/high risk disease the combination therapy (EBRT + HDR-BT) provides better oncological outcomes compared to EBRT monotherapy, even if the role of adjuvant hormone therapy is still unclear. Literature shows variable efficacy of BT in case of local recurrence after EBRT and radical prostatectomy even if few cases have been reported with short follow-up. Side effects are acceptable (urogenital toxicity, urinary incontinence, sexual function) and comparable with the other treatment modalities. So far, randomized controlled trials comparing the different treatment modalities are necessary to clarify indications and real efficacy.

Geometric evaluation of systematic transrectal ultrasound guided prostate biopsy

PURPOSE

Transrectal ultrasound guided prostate biopsy results rely on physician ability to target the gland according to the biopsy schema. However, to our knowledge it is unknown how accurately the freehand, transrectal ultrasound guided biopsy cores are placed in the prostate and how the geometric distribution of biopsy cores may affect the prostate cancer detection rate.

MATERIALS AND METHODS

To determine the geometric distribution of cores, we developed a biopsy simulation system with pelvic mock-ups and an optical tracking system. Mock-ups were biopsied in a freehand manner by 5 urologists and by our transrectal ultrasound robot, which can support and move the transrectal ultrasound probe. We compared 1) targeting errors, 2) the accuracy and precision of repeat biopsies, and 3) the estimated significant prostate cancer (0.5 cm(3) or greater) detection rate using a probability based model.

RESULTS

Urologists biopsied cores in clustered patterns and under sampled a significant portion of the prostate. The robot closely followed the predefined biopsy schema. The mean targeting error of the urologists and the robot was 9.0 and 1.0 mm, respectively. Robotic assistance significantly decreased repeat biopsy errors with improved accuracy and precision. The mean significant prostate cancer detection rate of the urologists and the robot was 36% and 43%, respectively (p <0.0001).

CONCLUSIONS

Systematic biopsy with freehand transrectal ultrasound guidance does not closely follow the sextant schema and may result in suboptimal sampling and cancer detection. Repeat freehand biopsy of the same target is challenging. Robotic assistance with optimized biopsy schemas can potentially improve targeting, precision and accuracy. A clinical trial is needed to confirm the additional benefits of robotic assistance.

Association of [-2]proPSA with biopsy reclassification during active surveillance for prostate cancer

PURPOSE

Previous studies have suggested an association between [-2]proPSA expression and prostate cancer detection. Less is known about the usefulness of this marker in following patients with prostate cancer on active surveillance. Thus, we examined the relationship between [-2]proPSA and biopsy results in men enrolled in an active surveillance program.

MATERIALS AND METHODS

In 167 men from our institutional active surveillance program we used Cox proportional hazards models to examine the relationship between [-2]proPSA and annual surveillance biopsy results. The outcome of interest was biopsy reclassification (Gleason score 7 or greater, more than 2 positive biopsy cores or more than 50% involvement of any core with cancer). We also examined the association of biopsy results with total prostate specific antigen, %fPSA, [-2]proPSA/%fPSA and the Beckman Coulter Prostate Health Index phi ([-2]proPSA/free prostate specific antigen) × (total prostate specific antigen)(½)).

RESULTS

While on active surveillance (median time from diagnosis 4.3 years), 63 (37.7%) men demonstrated biopsy reclassification based on the previously mentioned criteria, including 28 (16.7%) of whom had reclassification based on Gleason score upgrading (Gleason score 7 or greater). Baseline and longitudinal %fPSA, %[-2]proPSA, [-2]proPSA/%fPSA and phi measurements were significantly associated with biopsy reclassification, and %[-2]proPSA and phi provided the greatest predictive accuracy for high grade cancer.

CONCLUSIONS

In men on active surveillance, measures based on [-2]proPSA such as phi appear to provide improved prediction of biopsy reclassification during followup. Additional validation is warranted to determine whether clinically useful thresholds can be defined, and to better characterize the role of %[-2]proPSA and phi in conjunction with other markers in monitoring patients enrolled in active surveillance.