Androgen Deprivation Therapy and Outcomes After Radiation Therapy in Black Patients With Prostate Cancer.

Importance: Prostate cancer in Black men compared with White men may be more sensitive to radiation therapy resulting in better outcomes in equal-access settings. The outcomes of androgen-deprivation therapy (ADT) vs radiation therapy itself remains uncharacterized. Objectives: To quantify any outcome modification by receipt of ADT on the association between Black race and prostate cancer outcomes following radiation therapy. Design, Setting, and Participants: This was a retrospective, nationwide cohort study of Black and White patients treated in the US Veterans Healthcare system between 2000 and 2020 receiving definitive radiation for localized prostate cancer. Data were analyzed from January 2000 to December 2020. Exposure: Patient self-identified race and use of ADT defined as any gonadotrophin-releasing hormone agonist or antagonist prescription within 6 months of radiation. Main Outcomes and Measures: Biochemical recurrence (BCR) from time of completion of radiation therapy (prostate-specific antigen nadir plus 2 ng/mL) and development of metastatic disease or prostate cancer mortality (PCSM) from time of recurrence. Results: A total of 26 542 patients (8716 Black men with median [IQR] age of 64 [59-69] years and 17 826 White men with median [IQR] age of 67 [62-72] years) received definitive radiation therapy for nonmetastatic prostate cancer and had complete staging and follow-up data. A total of 5144 patients experienced BCR (3384 White and 1760 Black patients). The cumulative incidence of BCR at 10 years was not significantly different between Black and White men (1602 [22.14%] vs 3099 [20.13%], respectively) with multivariable hazard ratio (HR) of 1.03 (95% CI, 0.97-1.09; P = .33). In men receiving ADT, Black men had an HR for BCR of 0.90 (95% CI, 0.82-0.99; P = .03) compared with White men, and in men not receiving ADT, Black men had an HR of 1.13 (95% CI, 1.05-1.22; P = .002). Black race was associated with a decreased risk of developing metastatic disease (HR, 0.90; 95% CI, 0.82-0.98; P = .02) or PCSM (subdistribution HR, 0.72; 95% CI, 0.63-0.82; P < .001) from time of biochemical recurrence. Conclusions and Relevance: Black patients treated with radiation appear to specifically benefit from the addition of ADT with regard to biochemical control. Additionally, BCR in Black men results in a lower rate of metastatic disease and death from prostate cancer. Future analyses of radiosensitivity in Black men should evaluate for the possibility of outcome modification by ADT.

Neighborhood Deprivation, Race and Ethnicity, and Prostate Cancer Outcomes Across California Health Care Systems.

Importance: Non-Hispanic Black (hereafter, Black) individuals experience worse prostate cancer outcomes due to socioeconomic and racial inequities of access to care. Few studies have empirically evaluated these disparities across different health care systems. Objective: To describe the racial and ethnic and neighborhood socioeconomic status (nSES) disparities among residents of the same communities who receive prostate cancer care in the US Department of Veterans Affairs (VA) health care system vs other settings. Design, Setting, and Participants: This cohort study obtained data from the VA Central Cancer Registry for veterans with prostate cancer who received care within the VA Greater Los Angeles Healthcare System (VA cohort) and from the California Cancer Registry (CCR) for nonveterans who received care outside the VA setting (CCR cohort). The cohorts consisted of all males with incident prostate cancer who were living within the same US Census tracts. These individuals received care between 2000 and 2018 and were followed up until death from any cause or censoring on December 31, 2018. Data analyses were conducted between September 2022 and December 2023. Exposures: Health care setting, self-identified race and ethnicity (SIRE), and nSES. Main Outcomes and Measures: The primary outcome was all-cause mortality (ACM). Cox proportional hazards regression models were used to estimate hazard ratios for associations of SIRE and nSES with prostate cancer outcomes in the VA and CCR cohorts. Results: Included in the analysis were 49 461 males with prostate cancer. Of these, 1881 males were in the VA cohort (mean [SD] age, 65.3 [7.7] years; 833 Black individuals [44.3%], 694 non-Hispanic White [hereafter, White] individuals [36.9%], and 354 individuals [18.8%] of other or unknown race). A total of 47 580 individuals were in the CCR cohort (mean [SD] age, 67.0 [9.6] years; 8183 Black individuals [17.2%], 26 206 White individuals [55.1%], and 13 191 individuals [27.8%] of other or unknown race). In the VA cohort, there were no racial disparities observed for metastasis, ACM, or prostate cancer-specific mortality (PCSM). However, in the CCR cohort, the racial disparities were observed for metastasis (adjusted odds ratio [AOR], 1.36; 95% CI, 1.22-1.52), ACM (adjusted hazard ratio [AHR], 1.13; 95% CI, 1.04-1.24), and PCSM (AHR, 1.15; 95% CI, 1.05-1.25). Heterogeneity was observed for the racial disparity in ACM in the VA vs CCR cohorts (AHR, 0.90 [95% CI, 0.76-1.06] vs 1.13 [95% CI, 1.04-1.24]; P = .01). No evidence of nSES disparities was observed for any prostate cancer outcomes in the VA cohort. However, in the CCR cohort, heterogeneity was observed for nSES disparities with ACM (AHR, 0.82; 95% CI, 0.80-0.84; P = .002) and PCSM (AHR, 0.86; 95% CI, 0.82-0.89; P = .007). Conclusions and Relevance: Results of this study suggest that racial and nSES disparities were wider among patients seeking care outside of the VA health care system. Health systems-related interventions that address access barriers may mitigate racial and socioeconomic disparities in prostate cancer.