Epidemiology and racial differences of prostate cancer clinical states.
Authors: Stock Shannon R. , Burns Michael T. , Waller Justin , De Hoedt Amanda Marie , Ghate Sameer , Kim Jeri , Polascik Thomas J. , Shui Irene M , Freedland Stephen J. 
Published: June 2022

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Background: There is a lack of data on the incidence rates (IRs) and racial differences in advanced prostate cancer (PC) clinical states. This is the first study to evaluate PC IRs among Black and White men in the Veterans Affairs Healthcare System (VAHCS) in the following clinical states: non-metastatic hormone-sensitive PC (nmHSPC); de novo metastatic HSPC (mHSPC); non-metastatic castration-resistant PC (nmCRPC); metastatic CRPC (mCRPC). Methods: This retrospective cohort study included adult Black and White men who were active users of the VAHCS, having ≥ two visits at VA centers over any 18-month interval during the study period (2012-2019). PC was identified by ≥ two ICD codes for PC on separate dates. Metastatic status was identified by an algorithm of ICD codes and common treatments for metastatic PC. Castrate resistant status was determined based on rising PSA during periods of continuous androgen deprivation therapy. Annual IRs for each clinical state and rate ratios (RR) for race were standardized using age and race-specific population estimates from the U.S. Census. The joinpoint regression software 4.9.0.0 was used to evaluate trends and identify change points in IRs over time. Results: 2019 IRs (per 100K person-years) and 95% confidence intervals among Black and White men respectively by clinical state were 453.0 (441.2, 464.7) and 205.3 (201.5, 209.1) (nmHSPC); 33.7 (30.4, 37.0) and 15.1 (14.1, 16.0) (mHSPC); 23.4 (21.0, 25.9) and 8.5 (7.8, 9.1) (nmCRPC); and 49.1 (45.5, 52.8) and 19.4 (18.4, 20.3) (mCRPC). The RR for all clinical states was significantly higher for Black vs. White men (all p < 0.0001): 2.2 (nmHSPC and mHSPC), 2.8 (nmCRPC), and 2.5 (mCRPC). Although IRs varied over time, these RRs were consistent across time. Trends in IRs over time were also consistent by race. From 2012, the IRs for nmHSPC declined to a nadir in 2016 (annual percent change (APC) -9.1%) and then increased through 2019 (APC = 3.1%). IRs for mHSPC increased throughout the study period (APC = 10.6%). IRs for nmCRPC decreased from 2012 to a nadir in 2014 (APC = -9.3%) and then increased through 2019 (APC = 3.8%). IRs for mCRPC increased from 2012 to 2016 (APC = 7.7%) and then leveled off through 2019 (APC = -0.2%). Conclusions: Our findings provide novel and comprehensive data on IRs across prostate cancer clinical states by race and over time within the VAHCS. Despite the VAHCS providing an environment of relatively equal access to care, Black men experience a disproportionate burden of PC with IRs over 2-fold higher for all clinical states relative to White men. This highlights that resolving access to care alone is unlikely to fully eliminate PC racial differences and that there are other multifactorial issues to address. The temporal trends for nmHSPC observed in our study, including the nadir in 2016, are consistent with the timing of the 2012 US Preventive Services Task Force guidelines advising against PSA screening and the subsequent draft reversal in 2017.