Introduction

Digital rectal examination (DRE) is part of the clinical evaluation of men on active surveillance (AS). The purpose of the present study is to analyze the value of DRE as a predictor of upgrading in a population of men with prostate cancer (PCa) treated with AS.

Methods

We used the prostate biopsy (PBx) database from an academic center, including PBx from 2006-2018, and identified 2029 confirmatory biopsies (CxPBx) of men treated with AS, of which 726 men had both diagnostic (initial) and CxPBx information available. We did a descriptive analysis and evaluated sensitivity, specificity, and predictive values of DRE for the detection of clinically significant PCa (csPCa). Multivariable regression analysis was done to identify predictors of csPCa. The primary outcome was to evaluate DRE as a predictor of the presence of csPCa at CxPBx.

Results

Among the 2029 patients with a CxPBx, 75% had PCa, and of these, 30.3% had upgrading to International Society of Urologic Pathologists (ISUP) grade ≥2. Thirteen percent of men had a suspicious DRE (done by their treating physician). Sensitivity, specificity, negative and positive predictive values of DRE to detect csPCa were best with a prostate-specific antigen (PSA) <4 ng/ml (27%, 88%, 31%, and 87%, respectively). A suspicious DRE at CxPBx, particularly if the DRE at diagnosis was negative, was a predictor of csPCa (odds ratio [OR] 2.34, p=0.038). The main limitation of our study is the retrospective design and the lack of magnetic resonance imaging.

Conclusions

We believe DRE should still be used as part of AS and can predict the presence of csPCa, even with low PSA values. A suspicious nodule on DRE represents a higher risk of upgrading and should prompt further assessment.

INTRODUCTION:Treatment using abiraterone acetate plus prednisone, enzalutamide, cabazitaxel, and radium-223 (Ra-223) improves overall survival (OS) and quality of life for patients with metastatic castrate-resistant prostate cancer (mCRPC). Despite their proven benefits, access to these therapies is not equal across Canada. METHODS:We describe provincial differences in access to approved mCRPC therapies. Data sources include the pan-Canadian Oncology Drug Review database, provincial cancer care resources, and correspondence with pharmaceutical companies. RESULTS:Both androgen receptor-axis-targeted therapies (ARATs), abiraterone acetate plus prednisone and enzalutamide, are funded by provinces in the pre-and post-chemotherapy setting, however, sequential ARAT use is not funded. "Sandwich" therapy, where one ARAT is used pre-chemotherapy and a second is used upon progression on chemotherapy, is funded in six provinces: Ontario (ON), Alberta, New Brunswick, Prince Edward Island (PEI), Nova Scotia (NS), and Newfoundland and Labrador. Ra-223 is funded in five provinces: ON, Quebec (QC), British Columbia (BC), Saskatchewan, and Manitoba to varying degrees; ON allows Ra-223 either pre- or post-chemo (not both); QC allows Ra-223 post-chemo unless chemo is not tolerated; BC allows Ra-223 if other life-prolonging mCRPC therapies have been received or ineligible. Cabazitaxel is funded in all provinces post-docetaxel, except QC and PEI. Cabazitaxel is not funded as fist-line treatment for mCPRC or in combination with other agents. In ON, BC, QC, and PEI, cabazitaxel is not funded after progression on an ARAT in the post-chemotherapy setting. CONCLUSIONS:While all provinces have access to docetaxel and ARATs, sandwiching sequential ARATs with docetaxel is funded only in select provinces. Ra-223 and cabazitaxel access is not ubiquitous across Canada. Such inequalities in access to life-prolonging therapies could lead to disparities in survival and quality of life among patients with mCRPC. Further research should quantify interprovincial variation in outcomes and cost that may result from variable access.