Hypofractionated Radiation Therapy (HFRT) of Breast/Chest Wall and Regional Nodes in Locally Advanced Breast Cancer. Toxicity Profile and Survival Outcomes in Retrospective Monoistitutional Study

Aim of the study was to evaluate hypofractionated radiation therapy (HFRT) of the breast/chest wall and regional nodes in patients with locally advanced breast cancer. One hundred and twenty-two patients were treated with HFRT (42.4Gy/16fractions). HFRT showed excellent local control, survival rates and low toxicity profile and may be considered a valid therapeutic option for these patients. AIM: To evaluate the efficacy and safety of hypofractionated radiation therapy (HFRT) of the breast/chest wall and regional nodes in patients with locally advanced breast cancer and positive lymph nodes. Materials and Methods: One hundred and t wenty-t wo patients treated between October 2016 and March 2020 with HFRT were retrospectively reviewed. A total dose of 42.4 Gy was delivered to the chest wall and lymph nodes in 16 fractions of 2.65 Gy each, using the IMRT technique. Patients treated with breast-conserving surgery received an overdose (concomitant boost of 3 Gy daily) with the SIB (Simultaneous Integrated Boost) technique. Results: Median age at diagnosis was 58 years (range 34-86 years) and median follow-up was 22 months (range 6-48 months). Overall survival (OS) at 1, 2 and 3 years was 100%, 97.3% and 90%, respectively. Disease-free survival (DFS) at 1, 2, and 3 years was 91.4%, 87%, and 84.8%, respectively. Distant metastasis-free survival (MFS) at 1, 2 and 3 years was 93.1%, 88% and 85.7%, respectively. Two patients (1.6%) experienced local recurrence on the chest wall during FUP. Twenty-one patients (17%) showed a grade 2 dermal toxicity, no grade 3 acute skin toxicity was found. Sixteen patients (13%) showed early-stage arm lymphedema (grade ≤2). Twenty-three patients (19%) showed a grade 2 late skin toxicit y. Twent y patients (16%) had grade ≤2 late arm lymphedema. Conclusion: Given the excellent local control, survival rates and the low toxicity profile demonstrated, HFRT could be considered a valid therapeutic option in patients with locally advanced breast cancer.