ASPO Abstracts
Prostate Cancer Incidence and Mortality Following a Negative Biopsy in a Screened Cohort
Category: Early Detection & Risk Prediction
Conference Year: 2019
Abstract Body:
Purpose: To estimate prostate cancer (PCa) incidence and mortality following a negativebiopsy for prostate cancer in a cohort of men undergoing prostate cancer screening. Methods: The Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial randomized participants 55-74 years to an intervention versus control arm. Intervention arm menreceived annual prostate-specific antigen (PSA) tests for 6 years and annual digital rectal exams (DRE)for 4 years. We examined the cohort of men with a positive PSA (> 4 ng/ml) or DRE screen followed withinone year by a negative biopsy, defined as a biopsy with no PCa diagnosis within 90 days. PCa incidenceand mortality rates in this cohort from the time of first negative biopsy were analyzed as a function ofPSA level at biopsy and other factors such as age and race. Cumulative incidence and mortalityprobabilities were derived using Kaplan-Meier curves. Multivariate proportional hazards regression wasutilized to estimate hazard ratios (HRs) of PCa death by PSA level, controlling for age and race.Results: The cohort included 3215 men. Median (25th/75th) age at biopsy was 65 (61/69)years; biopsies occurred between 1994-2006. Median follow-up time was 15.0 years. By PSA level, 31%, 43%,14% and 6% were <4, 4-7, 7-10 and >10 ng/ml, respectively (5% unknown). A total of 824 PCa caseswere diagnosed. The 20-year probability of PCa diagnosis following a negative biopsy was 30.2%(95% CI: 28.4-33.2). By PSA level, 20-year PCa cumulative incidence probabilities were 14.8% (<4),36.9% (4-7), 38.2% (7-10) and 45.2% (>10). There were 38 PCa deaths. The overall cumulative probabilityof PCa death at 20 years was 1.97% (95% CI: 1.2-2.7%). By PSA level, 20-year PCA deathprobabilities were 1.53% (<4), 1.62% (4-7), 2.92% (7-10) and 4.62% (>10). Compared to men with PSA of 4-7ng/ml, those with levels of <4, 7-10 and >10 had HRs for PCa mortality of 0.75 (95% CI: 0.3-1.8), 1.4(95% CI: 0.6-3.5) and 3.0 (95% CI: 1.2-7.3), respectively. Per 5 ng/ml increase in PSA, the HR for PCamortality was 1.44 (p=0.01). Conclusions: The mortality rate from prostate cancer following a negative biopsy is lowthrough 20 years of follow-up, particularly among men with PSA levels < 10 ng/ml.
Keywords: Negative biopsyPCa incidencePCa mortality