Hypofractionation Is an Acceptable Alternative to Conventional Fractionation in the Treatment of Postlumpectomy Ductal Carcinoma In Situ With Radiotherapy
The standard dose of postlumpectomy radiotherapy (RT) for ductal carcinoma in situ (DCIS) is 50 Gy in 25 fractions using conventional fractionation (CF). However, in invasive carcinoma, hypofractionation (HF) with 40 to 42.6 Gy in 15 to 16 fractions has largely become a standard of care. The purpose of this study was to review the management of postlumpectomy DCIS in terms of RT dose-fractionation and its impact on local recurrence (LR), in one of the largest Canadian academic centers.Methods and Materials
Between 2003 and 2008, a total of 348 women with DCIS were treated with postlumpectomy RT. Patient characteristics, histopathology, dose-fractionation, use of endocrine therapy, local, regional, contralateral breast recurrences, and cause of death were collected. Local recurrence-free survival was determined. Univariate and multivariate analyses were performed to identify risk factors for LR.Results
The median age of the cohort was 59 years. Two hundred two (58%) patients received CF and 146 (42%) HF. Initially, the yearly proportion of HF was 34%, but increased up to 68% since 2007. Estrogen receptor was positive in 195 patients, and 43% of those received endocrine therapy. With a median follow-up of 64.8 months, 36 LRs were detected. The 5-year local recurrence-free survival rate was 94% for the HF group versus 91% for the CF group (P = .80). On multivariate analysis, only the use of endocrine therapy showed a trend towards decreasing LR (hazard ratio, 0.44; 95% confidence interval, 0.18-1.08; P = .07).Conclusions
The utilization of HF for DCIS postlumpectomy has increased over time and is a valid option as it results in similar rates of local control.Micro-Abstract
Ductal carcinoma in situ is often treated by lumpectomy and breast radiotherapy (RT) using conventional fractionation. We reviewed our institution's ductal carcinoma in situ RT management and its impact on local recurrence. Over a 6-year period, the utilization of hypofractionated radiotherapy increased with time and with a median follow-up of 65 months, this regimen had outcomes equal to conventional RT.