Assessment of Postmastectomy Radiation Therapy Receipt by Age and Association With Outcomes in Women With Breast Cancer.

PURPOSE: Postmastectomy radiation therapy (PMRT) reduces locoregional recurrence (LRR) and improves overall survival (OS) in patients with breast cancer. Young age has been recognized as a risk factor for LRR. The primary objective of this study was to determine if recommendations for PMRT differed among patients younger than 50 years as compared to women aged 50 years or older. METHODS: We reviewed medical records of patients with breast cancer who underwent mastectomy with or without PMRT from 2010 through 2018. Univariable and multivariable models were used to estimate the association of age with PMRT. RESULTS: Of 2471 patients, 839 (34%) were <50 years; 1632 (66%) were ≥50 years. Patients <50 years had a higher percentage of grade 3 tumors, hormone receptor (HR) negative and/or Her-2/neu positive tumors, clinical stage T2/T3 tumors, and nodal involvement. Compared with patients ≥50 years, patients <50 years were more likely to undergo PMRT (OR 1.57; P = .001) and regional node irradiation (RNI) to the internal mammary nodes. Advanced clinical and pathologic stage, invasive tumor histology, the presence of lymphovascular invasion, and treatment with systemic chemotherapy were predictors of PMRT receipt for patients <50 years (P < .05). PMRT was associated with improved OS and recurrence free survival (RFS) among all patients (P < .01). CONCLUSION: Patients <50 years were more likely to undergo PMRT and to receive RNI to the internal mammary nodes but were also more likely to have other risk factors for recurrence that would warrant a PMRT recommendation. PMRT improved OS and RFS for all patients.

Effect of Delayed Oncoplastic Reduction Mammoplasty on Radiation Treatment Delay Following Breast-Conserving Surgery for Breast Cancer.

BACKGROUND: The purpose of this study was to evaluate the delay in initiating adjuvant radiation therapy (RT) after breast-conserving surgery (BCS) in patients with early-stage breast cancer who underwent oncoplastic reduction mammoplasty (ORM) following BCS compared with a matched cohort of patients who did not undergo ORM between BCS and RT. METHODS: Medical records of 112 women (56 ORMs and 56 matched non-ORMs) with carcinoma in situ or early-stage breast cancer treated with BCS were reviewed. ORM was performed in a delayed manner following BCS, allowing confirmation of negative surgical margins. Time to RT was defined as time from last oncologic surgery to start of RT. RESULTS: The median follow-up time was 6.8 years for the ORM cohort and 6.7 years for the control non-ORM cohort. Patients who underwent ORM following BCS experienced a significant delay in initiating RT (>8 weeks) than matched patients not undergoing ORM (66% vs. 34%; p < 0.001). Wound complications occurred in 44.6% (n = 25) of patients in the ORM cohort, which were mostly minor, including delayed wound healing and/or infection (39%). There was no significant difference in local recurrence between patients in the non-ORM and ORM cohorts (p = 0.32). CONCLUSIONS: This study demonstrates that ORM following BCS has the potential to delay RT >8 weeks, largely as a result of increased risk of wound complications; however, this delay did not impact local control. ORM can be safely considered for appropriately selected patients with breast cancer.