Abstract 4970: Inpatient outcomes and racial differences in male breast cancer: insights from the 2021 National Inpatient Sample

Abstract Introduction: Male breast cancer (MBC) accounts for 1% of all breast cancer patients. In the US, 2800 MBC new cases are diagnosed yearly. MBC patients have high mortality due to late and advanced stages at diagnosis. Understanding demographics and racial disparities in MBC is crucial, and may significantly impact morbidity and mortality. Method: We analyzed data from the National Inpatient Sample and identified patients admitted to the hospital with MBC diagnosis in 2021 using STATA BE 18.0 software. To accurately identify metastatic disease to the bone, lung, and meninges, we excluded patients with any of these concurrent diagnoses: melanoma, primary central nervous system (CNS) tumors, and prostate and lung cancer. We investigated baseline patient characteristics and stratified the results based on race. The primary endpoint was in-hospital mortality (IHM). Length of stay (LOS) and total charge (TOTCH) were secondary endpoints. Results were adjusted for age, race, insurance type, smoking, alcohol, liver disease (LD), diabetes (DM), chronic kidney disease (CKD), and congestive heart failure (CHF). Other factors including metastases to the bone, lung, meninges, history of chest radiation, protein energy malnutrition (PEM), and palliative care utilization were also assessed and adjusted for. Results: A total of 1,915 patients met criteria for inclusion. Of those, 75% were Caucasians,16% African Americans (AA), and 9.2% of other races. AA patients were significantly younger (mean age 64 vs. 69 years in non-AA, p<0.05), and more commonly in the lowest income quartile (49% vs. 22% for non-AA; p<0.05). Clinically, 24% had estrogen receptor-positive status, 10% had prior chest radiation, and 32% had metastatic disease (24% to the bones, 16% to lung, 11% to liver, and 5.4% to CNS). Comorbidities included smoking (40%), obesity (20%), type 2 DM (35%), coronary artery disease (27%), CHF (26%), and PEM (12%), Overall IHM was 5% with a mean 6-day LOS. Compared to non-AA, AA patients had significantly higher mortality rates (11% vs. 4 %, p<0.05) and longer LOS (9 vs 5.4 days; p< 0.05). TOTCH was higher in AA ($87,937 vs. $68,852) but did not reach significance (p=0.48). LD, CKD, and liver metastases were independent predictors of inpatient mortality. Palliative care utilization was 10% overall, and similar in both races (AA-16% vs non-AA 10%, p=0.15). Conclusion: Significant socio-economic and racial disparities impact MBC outcomes, with AA patients presenting at younger ages, experiencing longer LOS, and higher mortality rates. The high prevalence of comorbidities and metastatic disease at presentation highlights the need for earlier detection through screening and education programs, and for interventions to address racial disparities, namely in AA patients. Future research should focus on understanding potential barriers underlying these disparities, to develop strategies to mitigate them. Citation Format: Raj Shah, Anas Alqam, Elie Chalhoub, Khalil Choucair. Inpatient outcomes and racial differences in male breast cancer: insights from the 2021 National Inpatient Sample [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4970.