The Effect of Other-cause Mortality Adjustment on Access to Alternative Treatment Modalities for Localized Prostate Cancer Among African American Patients

Abstract

BackgroundAfrican American (AA) men might be less likely to benefit from certain treatment types for localized prostate cancer (PCa). ObjectiveTo test treatment rate differences between AA and Caucasian patients with clinically localized PCa, with and without adjustment for other-cause mortality (OCM). Design, setting, and participantsWithin the Surveillance Epidemiology and End Results (SEER) database (2004–2014), we identified 260 309 (94.0%) Caucasian and 15 534 (6.0%) AA patients with PCa. InterventionRadical prostatectomy (RP), external beam radiotherapy (EBRT), brachytherapy (BT), combination of BT and EBRT (BT+EBRT), or nonlocal treatment (NLT). Outcome measurements and statistical analysisWe used multivariable logistic regression to assess treatment rates according to race, with or without adjustment for OCM risk according to D’Amico risk classification. OCM was defined using a multivariable Cox regression model, developed using a 50% random sample and validated using the remaining 50%. Results and limitationsBefore OCM adjustment, AA patients were less likely to receive RP regardless of D’Amico risk (odds ratio [OR] 0.54 for low risk [LR], 0.45 for intermediate risk [IR], and 0.43 for high risk [HR]) and were less likely to receive BT if D’Amico intermediate risk (OR 0.84) or high risk (OR 0.89). After OCM risk adjustment, AA men were still less likely to receive BT (OR 0.53 for LR, 0.32 for IR, 0.22 for HR) and EBRT (OR 0.74 for LR, 0.69 for IR, 0.83 for HR), but were no longer less likely to receive RP (OR 2.58 for LR, 3.07 for IR, 2.67 for HR) regardless of their D’Amico risk classification. The Cox model of OCM risk was 74.9% accurate in the validation cohort. ConclusionsFor AA men, rates of treatment for localized PCa depend on OCM risk. Lack of OCM risk adjustment may incorrectly suggest that some treatments are delivered at a lower rate than for Caucasians, and vice versa. Patient summaryOur study critically appraised the validity of reported prostate cancer treatment rates for African American men when adjustment for other-cause mortality was not performed.