Abstract PO2-09-09: Racial/Ethnic Differences in Survival of Male Patients with Stage I-III Breast Cancer by Hormone Receptor Status Using Real-World Data
Authors: Freeman Jincong , Hara Jared , Omoleye Olasubomi , Li James , Guo Wenji 
Published: May 2024

Background: Male breast cancer (BC) is rare and accounts for &lt; 1.0% of all BCs in the US. Given its rarity and limited data, racial/ethnic differences in survival outcomes among men with early-stage BC (EBC) at the national level have not been well studied. In this study, we sought to estimate 5-year survival rates and assess how overall survival (OS) in male patients (pts) with EBC differed by race/ethnicity and by hormone receptor (HR) status.

Methods: Data were obtained from male pts with stage I-III BC in the 2004-2019 National Cancer Database (NCDB). Racial/ethnic groups included Asian or Pacific Islander (API), Black, Hispanic, and White. HR status was dichotomized as “negative/positive.” The Kaplan-Meier method was used to estimate 5-year OS by race/ethnicity and comparisons were made using log-rank tests. OS, defined as death or censored from the date of diagnosis to the date of death or last contact, was modeled using a multivariable Cox regression, as well as stratified by HR status. Cox models were adjusted for sociodemographic and clinicopathologic factors.

Results: Of 22,340 pts, 56.4% were aged ≥65 years; 81.7% were White, 12.4% Black, 3.7% Hispanic, and 2.3% API; 94.3% had HR-positive tumors. 5-year OS rates were greater in API (84.5%) and Hispanic (84.2%) pts as compared with 5-year OS of White pts (77.2%); however, Black pts had a lower rate of 5-year OS (73.4%) (p&lt; .001). Similar findings of estimated 5-year OS rates were observed across racial/ethnic groups stratified by HR status (Table). After adjusting for clinicopathologic factors, Black pts had a higher mortality risk than White pts (adjusted hazard ratio [aHR]=1.13, 95% CI: 1.01-1.25), while Hispanic (aHR=0.65, 95% CI: 0.51-0.85) and API (aHR=0.62, 95% CI: 0.45-0.86) pts had a lower risk of death than white pts. After further adjusting for sociodemographics, there was no significant OS difference between Black and White pts (aHR=0.98, 95% CI: 0.87-1.11); OS rates remained significantly higher in API (aHR=0.69, 95% CI: 0.50-0.96) and Hispanic (aHR=0.60, 95% CI: 0.46-0.79) pts than in White pts. Additionally, pts with a median household income of $50,354-63,332 (aHR=0.86, 95% CI: 0.75-0.99) or of ≥$63,333 (aHR=0.74, 95% CI: 0.64-0.86) had a lower risk of dying than those of &lt; $40,227. Uninsured pts (aHR=1.54, 95% CI: 1.12-2.12) or pts with public insurance (Medicare: aHR=1.54, 95% CI: 1.36-1.75; Medicaid: aHR=1.41, 95% CI: 1.13-1.77) had a higher risk of dying than privately insured pts. In the HR-positive cohort, similar mortality risks between racial/ethnic minoritized and White pts were observed (Table). However, in the HR-negative cohort, after adjusting for sociodemographic and clinicopathologic factors, API pts had a greater risk of death than White pts (aHR=2.75, 95% CI: 1.25-6.03); Black pts also had a higher mortality risk than White pts, though it was not statistically significant (aHR=1.37, 95% CI: 0.87-2.14).

Conclusions: In this large retrospective cohort of male EBC pts, API and Hispanic pts had higher OS than White pts. Higher income and private health insurance were associated with greater OS. Black pts had lower OS than their White counterparts when controlling for clinicopathologic factors; however, the difference was not significant after further controlling for sociodemographics. Addressing socioeconomic disparities and inequities that impact access to health care and services may help improve survival outcomes across racial/ethnic groups of male EBC pts.

Table. Racial and ethnic differences in overall survival of male patients with stage I-III breast cancer

Citation Format: Jincong Freeman, Jared Hara, Olasubomi Omoleye, James Li, Wenji Guo. Racial/Ethnic Differences in Survival of Male Patients with Stage I-III Breast Cancer by Hormone Receptor Status Using Real-World Data [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-09-09.