Neoadjuvant Radiation Therapy in the Treatment of Breast Cancer

Abstract

Radiation therapy improves locoregional control and increases breast cancer patient's survival. Its neoadjuvant setting is a rarely used alternative that favors tumor resectability and, in addition, allows immediate breast reconstruction. This study aims to characterize locally advanced breast cancer patients that were treated with neoadjuvant radiotherapy (naRT), its indications and results. Medical records were reviewed retrospectively. All patients diagnosed with breast cancer treated with curative-intent naRT in a Chilean oncologic hospital between January 2017 and 2019 were included. Inflammatory breast cancer cases and sarcomas were excluded. We described demographic, clinical and treatment characteristics, naRT indications and outcomes. Information was collected from 112 patients (98% women) referred from 7 public hospitals. The median age was 57 years [28-85 years]. At diagnosis, 78% corresponded to clinical stage cT4b, and 83% had cN+ axilla (axillary biopsy was performed in 44 cases, 35 were positive). 53% were classified as luminal B, 19% as triple negative, 17% as luminal A, and 11% as HER2 enriched. 98% of patients began treatment with neoadjuvant systemic therapy (91 patients received chemotherapy and 19 patients hormone therapy). naRT indications were: immediate breast reconstruction in 23% and contraindication or unsatisfactory response to systemic therapy in 77%. In 99% of naRT the dose was 45-50 Gy to the breast/chest wall and peripheral lymphatics. 86% of patients underwent surgery (14 patients did not undergo surgery due to disease progression or because they refused surgery and 2 patients were on the waiting list at the time of follow up). Immediate breast reconstruction was performed in 31 patients with a median age of 45 years, all of them were derived from 2 referral centers that suggest this altered sequence of treatments. Surgical biopsies of 96 patients were reviewed: 13% had pathological complete response in the breast/chest wall, 55% in the axilla, and 12% at both levels. 30% of post-surgical complications were reported in the subgroup of patients who continued follow-up in our institution (total of 47 patients). With a median follow-up of 29 months, 18% of the patients had died from breast cancer. naRT is not only an option when systemic therapy is not a good alternative, but also favors resectability of locally advanced tumors making pathological complete response and immediate breast reconstruction possible in selected cases, obtaining an oncological and reconstructive objective in the same surgery.