Hypofractionated Breast Irradiation after Conservative Breast Surgery in Node-Negative Breast Cancer Patients

Background: Radiation therapy after lumpectomy is a standard part of breast conserving therapy for invasive breast carcinoma. The most frequently used schedule worldwide is 60-66Gy in 30-33 fractions in 6-6.5 weeks, a time commitment that sporadically may dissuade some eligible women from undertaking treatment. This study was done to compare conventional whole breast radiotherapy versus hypofractionated schedule with local recurrence as the primary end point. The secondary endpoints were mortality, disease relapse (local and systemic), treatment toxicities and cosmetic outcome.Methods: Between September 2007 and April 2010 we treated 100 consecutive patients with operable invasive early stage breast cancer with external beam radiation therapy. Group I (50 patients) was assigned to 50Gy in 25 fractions to the whole breast plus a boost dose to the tumor bed of 16Gy in 8 fractions, while Group II patients were treated with hypofractionated schedule of 42.5Gy in 16 fractions to the whole breast plus a boost of 10Gy in 4 fractions.Results: With a median follow-up of 21 months (range 12-44 months). The study showed no statistical significant difference between the two treatment groups as regards local recurrence, disease relapse, mortality, treatment toxicities and cosmetic outcome. Statistically significant predictors for local recurrence were patient age, tumor grade, and tumor size, while for disease relapse and mortality tumor grade and size were the statistically significant variables.Conclusions: The clinical results showed a reasonably good feasibility of the accelerated hypofractionated schedule with similar results to conventional schedule.