Racial Disparities in Disease-Specific Survival and Surgical Management of Patients with Ductal Carcinoma In Situ with Microinvasion

Abstract

INTRODUCTION: Despite persistent racial disparities in breast cancer outcomes, there are no studies examining the impact of race on treatment of the rare entity Ductal Carcinoma In-Situ with Microinvasion (DCIS-MI). The objective of this study is to examine racial differences in disease-specific survival (DSS) and surgical management among breast cancer patients presenting with DCIS-MI. METHODS: The Surveillance, Epidemiology, and End Results (SEER) Program was queried for patients with breast cancer age 18+ diagnosed with DCIS-MI between January 1, 2010, and December 31, 2018. The study cohort was divided into non-Hispanic Black (NHB) and non-Hispanic White (NHW). Sociodemographic, clinical, and treatment variables were compared using bivariable analysis. DSS was evaluated using a Cox proportional hazards model. RESULTS: A total of 3,476 patients were identified, of whom 608 (17.5%) identified as NHB and 2868 (82.5%) identified as NHW. The median age for NHB women was slightly younger (57 years, range [50 to 66]) than NHW women (59 years [50 to 67]; p = 0.01). Compared with NHW patients, NHB patients were more likely to undergo mastectomy (42.6% vs 38.4%, p = 0.04) and axillary lymph node dissection (ALND; 6.4% vs 3.7%, p = 0.01). Additionally, NHB patients had a worse DSS (hazard ratio 3.2, p < 0.01) compared with NHW patients. Of note, there were no racial differences in chemotherapy (p = 0.19) and radiation therapy (p = 0.34). CONCLUSION: A higher percentage of NHB women with DCIS-MI have a mastectomy and ALND than NHW women, yet NHB women have worse DSS. Future studies should examine patient, physician, and institutional factors driving surgical disparities and poor survival in NHB patients with DCIS-MI.