Inflammatory breast cancer, trimodal treatment, and mortality: Does where you live matter?

Abstract

Background: The objective of this study is to examine the associations among neighborhood socioeconomic status, trimodal treatment, and disease-specific mortality among inflammatory breast cancer patients using data from the Surveillance, Epidemiology, and End Results program.

Methods: Patients diagnosed with inflammatory breast cancer (T4d) from 2010 to 2016 were identified in the Surveillance, Epidemiology, and End Results program. The cohort was stratified into neighborhood socioeconomic status groups (low, middle, high) based on National Cancer Institute census tract-level index. Trimodal treatment was defined as receipt of modified radical mastectomy, chemotherapy, and radiation therapy. Bivariable analysis, log-rank test, and a Cox proportional hazards model (hazard ratio, 95% confidence interval) were conducted to evaluate the relationship between neighborhood socioeconomic status, trimodal treatment, and disease-specific mortality.

Results: In total, 4,374 patients met study criteria. There was no difference between the neighborhood socioeconomic status groups in receipt of trimodal treatment (P = .19). On multivariable analysis, there was no association between low neighborhood socioeconomic status (hazard ratio 1.13, 0.98-1.30; ref high neighborhood socioeconomic status) or middle neighborhood socioeconomic status (hazard ratio 1.01, 0.88-1.64; ref high neighborhood socioeconomic status) and disease-specific mortality. Notably, triple negative subtype (hazard ratio 2.66, 2.21-3.20; ref luminal A) and Black race (hazard ratio 1.41, 1.16-1.72; ref White) were associated with a higher disease-specific mortality.

Conclusion: For inflammatory breast cancer patients in the Surveillance, Epidemiology, and End Results program, disease-specific mortality appears to be driven by tumor biology and patient characteristics instead of treatment disparities or neighborhood socioeconomic status.