Shortened Course of Radiotherapy for Breast Cancer After Surgery
Posted: Tuesday, January 12, 2021
The efficacy and safety of hypofractionated whole-breast irradiation for the treatment of breast cancer appear to be comparable to those of the conventional fractionated approach, according to Shu-Lian Wang, MD, of the Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China, and colleagues. The results of this multicenter phase III noninferiority trial were presented during the 2020 American Society for Radiation Oncology (ASTRO) Annual Meeting (Abstract 2040).
Patients with T1–2N0–3 invasive breast cancer who underwent breast-conservation surgery were randomly assigned in a 1:1 ratio to receive either hypofractionated (n = 368) or conventional fractionated (n = 366) radiotherapy. The conventional fractionated approach consisted of 50 Gy in 25 fractions over 5 weeks, followed by a boost of 10 Gy in 5 fractions over 1 week. The hypofractionated approach delivered 43.5 Gy in 15 fractions over 3 weeks, followed by a boost of 8.7 Gy in 3 daily fractions. Just 4.1% of patients received additional nodal irradiation.
A total of 13 local recurrence events were reported. The 5-year cumulative incidence of local recurrence was higher with conventional fractionated radiotherapy than with hypofractionated radiotherapy (2.0% vs. 1.2%, respectively; P = .017). The 5-year overall survival rate was 97.5% with hypofractionated radiotherapy and 98.0% with conventional fractionated radiotherapy (hazard ratio = 1.20; P = .680); the disease-free survival rates were 93.0% versus 94.1%, respectively (hazard ratio = 1.24; P = .422).
Acute and late toxicities did not seem to significantly differ between the arms; however, grade 2 to 3 acute skin toxicities occurred more frequently with conventional fractionated radiotherapy than with hypofractionated radiotherapy (P = .019). Excellent or good breast cosmesis was observed in 87.4% of patients treated with hypofractionated radiotherapy and in 88.9% of those treated with conventional fractionated radiotherapy (P = .775).
Disclosure: For full disclosures of the study authors, visit redjournal.org.