Abstract 2201: Prostate-specific antigen velocity is associated with future prostate cancer mortality among men in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial
Authors: Barr Erik , Berndt Sonja I. , Sorkin John D. , Huang Wen-Yi , Barry Kathryn Hughes 
Published: August 2018

Abstract
Higher prostate-specific antigen (PSA) velocity (change in PSA over time) measured after diagnosis or treatment is associated with poorer prognosis for prostate cancer patients. However, less is known about the association between PSA velocity measured prior to a diagnosis of cancer and future prostate cancer mortality. We evaluated whether PSA velocity is associated with the risk of prostate cancer mortality among men without a history of prostate cancer in the screening arm of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. As part of the PLCO trial, men in the screening arm were offered PSA screening at baseline in the trial and annually thereafter for five years. From the screening arm, we included 33,961 men who had at least two prediagnostic trial PSA measurements (to allow for PSA velocity calculation), among whom 167 later died of prostate cancer. We estimated PSA velocity and initial PSA concentration for each participant from the random slope and random intercept terms in a mixed effects model based on up to the first three trial PSA measures per person since participants varied in the number of available measures. We defined our study baseline for survival analysis as the time of the last PSA measurement used to calculate PSA velocity. Participants were 55 to 79 years of age at our study baseline, and we followed them for up to 18 years (through Dec. 31, 2012) for prostate cancer mortality, with a median follow-up time of 12.7 years (interquartile range: 10.7-14.4 years). We dichotomized PSA velocity as &lt;0.4 vs. ≥0.4 ng/mL/year for comparison with previous studies. We analyzed the association between PSA velocity and prostate cancer mortality using Cox proportional hazards regression, adjusting for initial PSA concentration, age, race, body mass index, our study baseline year, and past finasteride use. Higher PSA velocity was associated with an increased hazard of prostate cancer mortality compared to lower PSA velocity [Hazard Ratio (HR)=2.5, 95% Confidence Interval (CI): 1.7-3.7]. Additional adjustment for family history of prostate cancer or comorbidities did not appreciably alter findings. When we stratified by age at our study baseline, we observed a stronger association among men who were less than 70 years of age (HR=3.1, 95% CI: 1.9-4.9) than among those who were 70 years of age or older (p-interaction=0.04). In conclusion, in this large prospective study, higher prediagnostic PSA velocity was associated with an increased risk of prostate cancer mortality. Our findings suggest a potential benefit of using longitudinal PSA measures in predicting future prostate cancer mortality.
Citation Format: Erik Barr, Sonja I. Berndt, John D. Sorkin, Wen-Yi Huang, Kathryn Hughes Barry. Prostate-specific antigen velocity is associated with future prostate cancer mortality among men in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2201.