Janet E. Cowan

Active surveillance for the management of prostate cancer in a contemporary cohort

Active surveillance followed by selective treatment for men who have evidence of disease progression may be an option for select patients with early‐stage prostate cancer. In this article, the authors report their experience in a contemporary cohort of men with prostate cancer who were managed with active surveillance.

A 17-gene Assay to Predict Prostate Cancer Aggressiveness in the Context of Gleason Grade Heterogeneity, Tumor Multifocality, and Biopsy Undersampling

BACKGROUND Prostate tumor heterogeneity and biopsy undersampling pose challenges to accurate, individualized risk assessment for men with localized disease. OBJECTIVE To identify and validate a biopsy-based gene expression signature that predicts clinical recurrence, prostate cancer (PCa) death, and adverse pathology. DESIGN, SETTING, AND PARTICIPANTS Gene expression was quantified by reverse transcription-polymerase chain reaction for three studies-a discovery prostatectomy study (n=441), a biopsy study (n=167), and a prospectively designed, independent clinical validation study (n=395)-testing retrospectively collected needle biopsies from contemporary (1997-2011) patients with low to intermediate clinical risk who were candidates for active surveillance (AS). OUTCOME MEASURES AND STATISTICAL ANALYSIS The main outcome measures defining aggressive PCa were clinical recurrence, PCa death, and adverse pathology at prostatectomy. Cox proportional hazards regression models were used to evaluate the association between gene expression and time to event end points. Results from the prostatectomy and biopsy studies were used to develop and lock a multigene-expression-based signature, called the Genomic Prostate Score (GPS); in the validation study, logistic regression was used to test the association between the GPS and pathologic stage and grade at prostatectomy. Decision-curve analysis and risk profiles were used together with clinical and pathologic characteristics to evaluate clinical utility. RESULTS AND LIMITATIONS Of the 732 candidate genes analyzed, 288 (39%) were found to predict clinical recurrence despite heterogeneity and multifocality, and 198 (27%) were predictive of aggressive disease after adjustment for prostate-specific antigen, Gleason score, and clinical stage. Further analysis identified 17 genes representing multiple biological pathways that were combined into the GPS algorithm. In the validation study, GPS predicted high-grade (odds ratio [OR] per 20 GPS units: 2.3; 95% confidence interval [CI], 1.5-3.7; p<0.001) and high-stage (OR per 20 GPS units: 1.9; 95% CI, 1.3-3.0; p=0.003) at surgical pathology. GPS predicted high-grade and/or high-stage disease after controlling for established clinical factors (p<0.005) such as an OR of 2.1 (95% CI, 1.4-3.2) when adjusting for Cancer of the Prostate Risk Assessment score. A limitation of the validation study was the inclusion of men with low-volume intermediate-risk PCa (Gleason score 3+4), for whom some providers would not consider AS. CONCLUSIONS Genes representing multiple biological pathways discriminate PCa aggressiveness in biopsy tissue despite tumor heterogeneity, multifocality, and limited sampling at time of biopsy. The biopsy-based 17-gene GPS improves prediction of the presence or absence of adverse pathology and may help men with PCa make more informed decisions between AS and immediate treatment. PATIENT SUMMARY Prostate cancer (PCa) is often present in multiple locations within the prostate and has variable characteristics. We identified genes with expression associated with aggressive PCa to develop a biopsy-based, multigene signature, the Genomic Prostate Score (GPS). GPS was validated for its ability to predict men who have high-grade or high-stage PCa at diagnosis and may help men diagnosed with PCa decide between active surveillance and immediate definitive treatment.

Outcomes of Active Surveillance for Men With Intermediate-Risk Prostate Cancer

PURPOSE Active surveillance (AS) is an option for the initial management of early-stage prostate cancer. Current risk stratification schema identify patients with low-risk disease who are presumed to be most suitable for AS. However, some men with higher risk disease also elect AS; outcomes for such men have not been widely reported. PATIENTS AND METHODS Men managed with AS at University of California, San Francisco, were classified as low- or intermediate-risk based on serum prostate-specific antigen (PSA), Gleason grade, extent of biopsy involvement, and T stage. Clinical and demographic characteristics, and progression in terms of Gleason score, PSA kinetics, and active treatment were compared between men with low- and intermediate-risk tumors. RESULTS Compared to men with low-risk tumors, those with intermediate-risk tumors were older (mean, 64.9 v 62.3 years) with higher mean PSA values (10.9 v 5.1 ng/mL), and more tumor involvement (mean, 20.4% v 15.3% positive biopsy cores; all P < .01). Within 4 years of the first positive biopsy, the clinical risk group did not differ in terms of the proportions experiencing progression-free survival, (low [54%] v intermediate [61%]; log-rank P = .22) or the proportions who underwent active treatment (low [30%] v intermediate [35%]; log-rank P = .88). Among men undergoing surgery, none were node positive and none had biochemical recurrence within 3 years. CONCLUSION Selected men with intermediate-risk features be appropriate candidates for AS, and are not necessarily more likely to progress. AS for these men may provide an opportunity to further reduce overtreatment of disease that is unlikely to progress to advanced cancer.

Validation of a Cell-Cycle Progression Gene Panel to Improve Risk Stratification in a Contemporary Prostatectomy Cohort

PURPOSE We aimed to validate a previously described genetic risk score, denoted the cell-cycle progression (CCP) score, in predicting contemporary radical prostatectomy (RP) outcomes. METHODS RNA was quantified from paraffin-embedded RP specimens. The CCP score was calculated as average expression of 31 CCP genes, normalized to 15 housekeeper genes. Recurrence was defined as two prostate-specific antigen levels ≥ 0.2 ng/mL or any salvage treatment. Associations between CCP score and recurrence were examined, with adjustment for clinical and pathologic variables using Cox proportional hazards regression and partial likelihood ratio tests. The CCP score was assessed for independent prognostic utility beyond a standard postoperative risk assessment (Cancer of the Prostate Risk Assessment post-Surgical [CAPRA-S] score), and a score combining CAPRA-S and CCP was validated. RESULTS Eighty-two (19.9%) of 413 men experienced recurrence. The hazard ratio (HR) for each unit increase in CCP score (range, -1.62 to 2.16) was 2.1 (95% CI, 1.6 to 2.9); with adjustment for CAPRA-S, the HR was 1.7 (95% CI, 1.3 to 2.4). The score was able to substratify patients with low clinical risk as defined by CAPRA-S ≤ 2 (HR, 2.3; 95% CI, 1.4 to 3.7). Combining the CCP and CAPRA-S improved the concordance index for both the overall cohort and low-risk subset; the combined CAPRA-S + CCP score consistently predicted outcomes across the range of clinical risk. This combined score outperformed both individual scores on decision curve analysis. CONCLUSION The CCP score was validated to have significant prognostic accuracy after controlling for all available clinical and pathologic data. The score may improve accuracy of risk stratification for men with clinically localized prostate cancer, including those with low-risk disease.

Do adenocarcinomas of the prostate with gleason score (GS)≤6 have the potential to metastasize to lymph nodes?

Although rare, there are cases within reported series of men with Gleason score (GS)⩽6 on radical prostatectomies that show pelvic lymph node (LN) metastases. However, there are no studies on whether pelvic LN metastases occur in tumors with GS⩽6 using the International Society of Urological Pathology (ISUP) updated GS system. We performed a search of the radical prostatectomy databases at 4 large academic centers for cases of GS⩽6. Only prostatectomies submitted and embedded in entirety with pelvic LN dissections were included. A combined total of 14,123 cases were identified, of which 22 cases had a positive LN. Histopathologic review of 19 cases (3 cases unavailable for review) showed higher grade than originally reported by the pathologists in all cases. Of the 17 pre-ISUP reviewed cases, 2 were upgraded to 4+3=7 with both cribriform and poorly formed glands. One case was upgraded to 4+3=7 with tertiary pattern 5 displaying cribriform glands, poorly formed glands, and cords of single cells. Eleven cases were upgraded to 3+4=7 with glomeruloid structures and small to large cribriform glands (1 of these also had features of ductal adenocarcinoma). Two cases had tertiary pattern 4 with small cribriform glands. One case had a prominent colloid component that would currently be graded as 4+5=9 because of large cribriform glands and solid sheets of cells within the mucin. Of the 2 post-ISUP cases, 1 demonstrated tertiary pattern 4, and the other showed GS 3+4=7 with irregular cribriform glands. Undergrading is the primary reason for LN positivity with GS⩽6, which has decreased significantly since the adoption of the ISUP grading system in 2005. Of over 14,000 totally embedded radical prostatectomies from multiple institutions, there was not a single case of a GS⩽6 tumor with LN metastases. In contrast to prevailing assumptions, GS⩽6 tumors do not appear to metastasize to LNs. Rather, Gleason pattern 4 or 5, as better defined by the current ISUP updated grading system, is required for metastatic disease.

Pathological Outcomes of Candidates for Active Surveillance of Prostate Cancer

PURPOSE Active surveillance of prostate cancer has emerged as a viable treatment option for men with features of low risk disease. Five prospective studies have enrolled patients for active surveillance with varying inclusion criteria. We evaluated the pathological outcomes of men meeting published criteria for active surveillance who elected immediate radical prostatectomy to assess the risk of under grading and under staging in candidates for active surveillance. MATERIALS AND METHODS Data were extracted from our institutional urological oncology database for all men who underwent radical prostatectomy between 1996 and 2007. The primary outcome was pathological up staging, defined as the occurrence of extracapsular extension or seminal vesicle involvement. Pathological upgrading was identified as a secondary outcome. We determined the proportion of men who would have qualified for each published active surveillance study and the respective rates of upgrading and up staging in each group. RESULTS We identified 1,097 men who underwent radical prostatectomy with a mean age of 59 years. Overall 28% of the men experienced a Gleason upgrade, 21% had extracapsular extension and 11% had seminal vesicle involvement. In men qualifying based on published active surveillance inclusion criteria, rates of upgrading varied between 23% and 35%, the incidence of extracapsular extension ranged from 7% to 19% and seminal vesicle involvement ranged from 2% to 9%. CONCLUSIONS Varying entry criteria for active surveillance show different rates of adverse pathological features at radical prostatectomy. Predictably fewer men met the more stringent criteria but these men had a lower incidence of seminal vesicle involvement and extracapsular extension. Such data can be used to advise men of the risks of active surveillance.

Changes in Prostate Cancer Grade on Serial Biopsy in Men Undergoing Active Surveillance

PURPOSE Active surveillance is now considered a viable treatment option for men with low-risk prostate cancer. However, little is known regarding changes in Gleason grade on serial biopsies over an extended period of time. PATIENTS AND METHODS Men diagnosed with prostate cancer between 1998 and 2009 who elected active surveillance as initial treatment, with 6 or more months of follow-up and a minimum of six cores at biopsy, were included in analysis. Upgrading and downgrading were defined as an increase or decrease in primary or secondary Gleason score. Means and frequency tables were used to describe patient characteristics, and treatment-free survival rates were determined by life-table product limit estimates. RESULTS Three hundred seventy-seven men met inclusion criteria. Mean age at diagnosis was 61.9 years. Fifty-three percent of men had prostate-specific antigen of 6 ng/mL or less, and 94% had Gleason score of 6 or less. A majority of men were cT1 (62%), had less than 33% of biopsy cores involved (80%), and were low risk (77%) at diagnosis. Median number of cores taken at diagnostic biopsy was 13, mean time to follow-up was 18.5 months, and 29% of men had three or more repeat biopsies. Overall, 34% (129 men) were found to have an increase in Gleason grade. The majority of men who experienced an upgrade (81%) did so by their second repeat biopsy. CONCLUSION A proportion of men experience an upgrade in Gleason score while undergoing active surveillance. Men who experience early upgrading likely represent initial sampling error, whereas later upgrading may reflect tumor dedifferentiation.

What Percentage of Patients With Newly Diagnosed Carcinoma of the Prostate are Candidates for Surveillance? An Analysis of the CaPSURE™ Database

PURPOSE Active surveillance is an option for men with clinically localized prostate cancer and may be suitable for those with very low risk disease. We determined the percentage of men in a large prostate cancer registry who met criteria predictive of latent prostate cancer. We also assessed the percentage of men meeting these criteria who chose surveillance. MATERIALS AND METHODS We conducted an observational study of 1,886 men diagnosed with clinically localized prostate cancer between 1999 and 2004 from the CaPSURE database. Outcomes were percent of men meeting Epstein surveillance criteria (prostate specific antigen less than 10 ng/ml, clinical T1 or T2a, prostate specific antigen density less than 0.15, fewer than 1 of 3 biopsy cores positive, and absence of Gleason pattern 4 and 5 on biopsy) and percent selecting surveillance stratified by risk group. RESULTS Of 1,886 men with all 5 criteria documented 16.4% (310 of 1,886) met all 5 surveillance criteria and 9.0% (28 of 310) of men in this very low risk category actually chose surveillance compared with 4.3% (68 of 1,576) of patients in other risk groups (p <0.01). On multivariable analysis of the entire cohort older age was the only demographic predictor of surveillance. Being in the very low risk group was also a predictor of surveillance. CONCLUSIONS Of men presenting with localized prostate cancer 16% met the criteria for very low risk disease. However, only a small subset of eligible men chose active surveillance, suggesting that it may be underused in the management of very low risk prostate cancer.

Prostate Cancer Managed with Active Surveillance: Role of Anatomic MR Imaging and MR Spectroscopic Imaging

PURPOSE To determine the role that magnetic resonance (MR) imaging and MR spectroscopic imaging findings obtained at the time of diagnosis play in the progression of disease in patients whose prostate cancer is being managed with active surveillance and to compare the role of these findings with the role of transrectal ultrasonography (US) findings. MATERIALS AND METHODS The institutional review board approved this HIPAA-compliant retrospective study, and informed consent was obtained from all patients whose records were to be entered into the research database. All patients who had prostate cancer managed with active surveillance and who had undergone both MR imaging and MR spectroscopic imaging of the prostate and transrectal US at time of diagnosis were identified. Two urologists blinded to the clinical outcome in these patients independently reviewed and dichotomized the MR imaging report and the MR spectroscopic imaging report as normal or suggestive of malignancy. One experienced urologist performed all US examinations that were then dichotomized similarly. Uni- and multivariate (with use of standard clinical variables) Cox models were fitted to assess time to cancer progression, defined as Gleason score upgrading, prostate-specific antigen velocity of more than 0.75 (microg x L(-1))/y, or initiation of treatment more than 6 months after diagnosis. RESULTS The final cohort included 114 patients with a median follow-up of 59 months. Patients with a lesion that was suggestive of cancer at MR imaging had a greater risk of the Gleason score being upgraded at subsequent biopsy (hazard ratio, 4.0; 95% confidence interval: 1.1, 14.9) than did patients without such a lesion. Neither MR spectroscopic imaging nor transrectal US could be used to predict cancer progression. CONCLUSION Abnormal prostate MR imaging results suggestive of cancer may confer an increased risk of Gleason score upgrade at subsequent biopsy. Although expensive, prostate MR imaging may help in counseling potential candidates about active surveillance.

The Relationship Between Prostate Specific Antigen Change and Biopsy Progression in Patients on Active Surveillance for Prostate Cancer

PURPOSE We assessed whether an association exists between a change in prostate specific antigen and biopsy progression in men on active surveillance. MATERIALS AND METHODS A cohort of patients undergoing active surveillance for prostate cancer was identified from the urological oncology database at our institution. Multivariate logistic regression was performed to determine whether prostate specific antigen velocity, defined as the change in ln(prostate specific antigen) per year, is associated with biopsy progression, defined as a Gleason upgrade or volume progression on repeat biopsy within 24 months of diagnosis. RESULTS A total of 241 men with a mean ± SD age of 61 ± 7 years and mean prostate specific antigen 4.9 ± 2.2 ng/ml met study inclusion criteria. Median time to repeat biopsy was 10 months (IQR 6-13). Biopsy progression developed in 55 men (23%), including a Gleason score upgrade in 46 (19%), greater than 33% positive cores in 11 (5%) and greater than 50% maximum single core positive in 12 (5%). The median prostate specific antigen ratio per year was 1.0 (IQR 0.95-1.03), although 1 man had a ratio of greater than 1.26 (doubled over 3 years) and 7 had a ratio of less than 1/1.26 (halved over 3 years). On multivariate analysis prostate specific antigen doubling within 3 years was associated with a 1.4-fold increase in the odds of biopsy progression (OR 1.4, 95% CI 0.6-3.4, p = 0.46). CONCLUSIONS There is little change in prostate specific antigen during the first 24 months of surveillance in men with well staged, low risk prostate cancer. We believe that these findings highlight the importance of repeat biopsy during surveillance.