Impact of the extent of resection on primary breast angiosarcoma survival.

Abstract

521 Background: The widely accepted standard of care in treating primary breast angiosarcoma involves surgical resection, often followed by adjuvant therapy (radiation and/or chemotherapy). The rarity of this disease has precluded large-scale analyses. The question regarding the impact of resection extent on survival has yet to be examined on a nationwide scale. Methods: The National Cancer Data Base (NCDB) from 2004-2014 identified primary breast angiosarcoma patients throughout the United States having undergone surgical resection. The extent of resection (mastectomy versus lumpectomy) was adjusted for several variables (including patient age, race, income, primary payer for care, tumor size, adjuvant therapies, and medical comorbidities) to assess its impact on breast angiosarcoma-related mortality. Results: Over this eleven-year span, 826 resected primary breast angiosarcoma patients were identified in the United States. Mastectomy was by far the most common surgical modality for primary breast angiosarcoma (86% of patients). Increasing tumor size was predictive for mastectomy over lumpectomy (p < 0.0001), and for involvement of adjuvant radiation therapy (p = 0.001). The extent of surgical resection was inversely predictive of radiation usage (p = 0.017). However, surgical modality was not significantly predictive of breast angiosarcoma-related mortality. Conclusions: Despite the frequent preference of mastectomy for primary breast angiosarcoma treatment (more than 6 of every 7 patients), there is no survival benefit of mastectomy versus lumpectomy. This lack of benefit should be discussed with patients, given the reduced operative morbidity of lumpectomy versus mastectomy. The Class IIB evidence provided from this analysis represents the highest level of evidence to-date governing management of this disease.