Hypofractionated Versus Conventional Fractionated Radiotherapy After Breast-Conserving Surgery in the Modern Treatment Era: A Multicenter, Randomized Controlled Trial From China

Abstract

PURPOSE No randomized trials have compared hypofractionated radiotherapy (HFRT) with conventional fractionated radiotherapy (CFRT) after breast-conserving surgery in the Asian population. This study aimed to determine whether a 3.5-week schedule of HFRT is noninferior to a standard 6-week schedule of CFRT in China. PATIENTS AND METHODS Patients from 4 Chinese institutions who had undergone breast-conserving surgery and had T1-2N0-3 invasive breast cancers participated this study. Patients were randomly assigned (1:1) using a computer-generated central randomization schedule, without stratification, to receive whole-breast irradiation with or without nodal irradiation, followed by tumor-bed boost, either at a dose of 50 Gy in 25 fractions over 5 weeks with a boost of 10 Gy in five fractions over 1 week (CFRT) or 43.5 Gy in 15 fractions over 3 weeks with a boost of 8.7 Gy in three daily fractions (HFRT). The primary endpoint was 5-year local recurrence (LR), and a 5% margin of 5-year LR was used to establish noninferiority. RESULTS Between August 2010 and November 2015, 734 patients were assigned to the HFRT (n = 368) or CFRT (n = 366) group. At a median follow-up of 73.5 months (interquartile range, 60.5-91.4 months), the 5-year cumulative incidence of LR was 1.2% in the HFRT group and 2.0% in the CFRT group (hazard ratio, 0.62; 95% CI, 0.20 to 1.88; P = .017 for noninferiority). There were no significant differences in acute and late toxicities, except that the HFRT group had less grade 2-3 acute skin toxicity than the CFRT group ( P = .019). CONCLUSION CFRT and HFRT with a tumor-bed boost may have similar low LR and toxicity.

Cost-effectiveness of postmastectomy hypofractionated radiation therapy vs conventional fractionated radiation therapy for high-risk breast cancer

“…Several RCTs have demonstrated equivalent treatment outcomes and toxicities between HFRT and CFRT after breast-conserving surgery in favorable-prognosis patients with early-stage breast cancer [32][33][34][35][36]. The first large RCT offered high-level evidence supporting the noninferior efficacy of postmastectomy HFRT vs CFRT in women with high-risk breast cancer [12].…”

Moderate hypofractionation remains the standard of care for whole-breast radiotherapy in breast cancer: Considerations regarding FAST and FAST-Forward

“…Moderate hypofractionation with 15-16 fractions of 2.6-2.7 Gy has been accepted as the standard of care for wholebreast external beam radiotherapy (EBRT) for invasive breast cancer in many countries [1][2][3]. This was based on the results from several well-powered randomized controlled trials showing comparable outcomes with regard to the risk of recurrence and chronic toxicity and with potential advantages in terms of reduced acute toxicity and improved cost-effectiveness [4][5][6][7][8][9][10][11][12]. First results on hypofractionated post-mastectomy radiotherapy have been published [13][14][15] with multiple trials on this topic and on hypofractionated regional nodal irradiation still ongoing.…”

The Role of Radiotherapy Fractionation And Volume In Patients With Early Breast Cancer After Conserving Surgery: A Systematic Review And Network Meta-Analysis 

“…Except for the natural defect blinding, all studies were considered as high quality and low risk of bias. Although there were some differences in patient selection criteria, adjuvant therapy regimens and the RT technique included in the trial, local control rates were similar in the CF-WBI group, suggesting that it may be a way to control differences in selection [1,[8][9][10][11][12][13][18][19][20][21]36].…”

“…The slow adoption of HF-WBI in Asia and the United States may be related to physicians' concerns about the cosmetic side effects, especially when used in conjunction with tumor-bed boost and chemotherapy, or its use in patients with different breast sizes, or the absence of validation outside Canada and the United Kingdom [6]. Several randomized controlled trials are currently comparing the effects of HF-WBI and CF-WBI in terms of local tumor control, breast appearance (cosmesis), late toxicity, overall survival, and patient satisfaction [8][9][10][11][12][13].…”