(S030) Breast Conservation in Young Women in the Modern Era

Jonathan Frandsen, MD, David Ly, MD, MPA, Gita Suneja, MD, MPH, Cindy Matsen, MD, Matthew Poppe, MD; Department of Radiation Oncology, Department of General Surgery, Huntsman Cancer Hospital, University of Utah School of Medicine

INTRODUCTION: Women aged < 40 years with breast cancer have worse outcomes compared with older women. Mastectomy (M) is often recommended as primary therapy, even for women with early-stage disease, because young women have been underrepresented in the landmark trials showing equivalence of breast conservation therapy (BCT) and M. Retrospective series comparing BCT and M show varying results, with some showing equivalence and others favoring M. Outcomes for BCT have improved significantly over time. The most appropriate comparison for BCT and M should reflect treatment techniques from the modern era. We hypothesize that in the modern treatment era, BCT and M have equivalent outcomes.

METHODS: Breast cancers diagnosed between 1975 and 2012 in women aged ≤ 40 years were collected from our institutional tumor registry. Four cohorts were then created based on year of diagnosis and treatment approach: BCT before 2000, BCT during or after 2000, M before 2000, and M during or after 2000. Vital status and cause of death were obtained from the government cancer registry. Kaplan-Meier survival estimates were used to analyze the primary outcome (freedom from locoregional recurrence [FFLR]) and secondary outcomes (overall survival [OS] and relapse-free survival [RFS]).

RESULTS: A total of 427 BCT candidates were identified from our institutional tumor registry. Among those who received BCT, OS and RFS were similar for those diagnosed before and after 2000. FFLR, however, was significantly improved after 2000. FFLR at 10 years was 78.8% vs 95.4% for BCT before and after 2000, respectively (P = .03). Among those who received M, OS (P = .03) and RFS (P < .0001) were significantly improved with diagnosis after 2000. FFLR at 10 years was 85.6% vs 93.1% for M before and after 2000, respectively (P = .08). When comparing BCT and M after 2000, FFLR, RFS, and OS were all similar. FFLR at 10 years was 95.4% vs 93.1% for BCT and M, respectively (P = .75). When comparing BCT and M before 2000, OS and RFS rates were similar.

CONCLUSIONS: Outcomes for women with breast cancer aged ≤ 40 years undergoing BCT and M have improved significantly over time, likely reflecting the advent of improved local and systemic therapies. In addition, for women treated after 2000, BCT appears to be safe and equivalent to M at 10 years in terms of FFLR, OS, and RFS.

Proceedings of the 97th Annual Meeting of the American Radium Society- americanradiumsociety.org