Abstract 5773: Cardiorespiratory fitness and PSA screening patterns in the Henry Ford FIT Project
Authors: Reiter-Brennan Cara , Dzaye Omar , Al-Mallah Mouaz H. , Dardari Zeina , Brawner Clinton A. , Lamerato Lois E. , Keteyian Steven J. , Ehrman Jonathan K. , Visvanathan Kala , Blaha Michael J. , Marshall Catherine Handy 
Published: September 2020

Abstract
Background: High levels of cardiorespiratory fitness (CRF) have been associated with a decreased risk of many cancers, but the association with prostate cancer (PCa) is less clear. A possible explanation for the lack of consistency is that prostate specific antigen (PSA) screening and in turn prostate cancer detection is more frequent in men with higher fitness although the relationship between fitness and PSA screening is not established.
Methods: The Henry Ford (HF) FIT Project is a retrospective cohort study of 69,894 consecutive patients who underwent physician-referred exercise stress testing from 1991 through 2009. Cancer diagnosis was identified through linkage to the HF tumor registry. We included men aged 40-70 yr who had CRF testing beginning in 1995 (when PSA screening became widespread), without prevalent cancer, followed at least 3 yrs and up to 10 years, who never develop prostate cancer (n=12,442). CRF was measured in metabolic equivalents of task (METs) and categorized as less than 6 (ref), 6-9, 10-11, and at least 12. PSA values were abstracted from the HF electronic medical record between 1995 and 2010. Individuals with at least 3 screening PSA tests were categorized as high screeners. Logistic regression was used to evaluate the relationship between CRF and high PSA screeners, adjusted for age at stress test and race.
Results: Participants had a mean age of 54 ± 8 yrs (67% white; 25% black) and mean follow-up was 7±2 yrs. Compared to individuals with low fitness (less than 6 METs, reference), those with higher fitness (6-9, 10-11, at least 12 METs) had higher odds of being a high PSA screener (Table). When stratified by race, the OR for black patients were not statistically different than white patients (Table). Results were similar among those with comorbidities (myocardial infarction, heart failure, or diabetes) at baseline.
Odds ratio of being a high screener (at least 3 PSA tests) in individuals followed 3-10 yearsMETs categoryAll (n=12,442Whites (n=8,356Blacks (n=3,049)Patients w/comorbidities (n=3,924)&lt;6RefRefRefRef6-91.6(1.3-1.8)1.6(1.3-2.0)1.4(1.1-1.9)1.6(1.3-2.0)10-111.9(1.6-2.2)1.9(1.6-2.4)1.7(1.3-2.2)2.0(1.7-2.4)&gt;=122.4 (2.1-2.9)2.5(2.0-3.1)2.1(1.6-2.8)3.2(2.5-4.0)
Conclusion: High CRF is associated with more frequent PSA screening. This points towards a healthy screening bias and should be accounted for in studies looking at fitness and incident prostate cancer.
Citation Format: Cara Reiter-Brennan, Omar Dzaye, Mouaz H. Al-Mallah, Zeina Dardari, Clinton A. Brawner, Lois E. Lamerato, Steven J. Keteyian, Jonathan K. Ehrman, Kala Visvanathan, Michael J. Blaha, Catherine Handy Marshall. Cardiorespiratory fitness and PSA screening patterns in the Henry Ford FIT Project [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5773.