Clinical impact of delaying initiation of radiotherapy in patients with breast cancer: stages 0, I and II, a retrospective observational study

Background There is no consensus on how long the initiation of radiotherapy (RT) can be delayed after surgery without a negative impact on survival. Materials and methods We conducted a retrospective study of 278 patients with stage 0–II breast cancer, all of whom were treated with surgery and RT, with those at stages I–II also receiving chemotherapy. Patients were followed-up for 5 years after diagnosis to assess disease-free and overall survival.The independent variable was the delay in the initiation of RT, assessed by two criteria: time since the last treatment, considered acceptable if ≤6 weeks, and time since surgery, considered acceptable if ≤7 months, these cut-offs being used to categorise patients into two groups according to the length of delay. Results No statistically significant differences were observed in the probability of disease-free survival ( p =0·412) or overall survival ( p =0·890). The appearance of recurrence was 5–59 months, with an average of 38·50 (14·31). Conclusions Delaying the initiation of RT for more than 6 weeks after last treatment does not seem to have a negative impact on disease-free or overall survival.