Evaluation of the Clinical Outcomes of Altered Fractionated Radiotherapy in Node Positive Breast Cancer (A Retrospective Study)

Abstract

P-operative radiotherapy plays a major role in the treatment of breast cancer patients as major Prandomized trials and meta-analyses established its benefit in improving DFS and OS. Typical radiation treatment extended over at least 5 weeks with 1.8 – 2 Gy/fraction. But following new radiobiological data suggesting that breast cancer tissue might have a lower α/β ratio than originally assumed and thus sensitive to increased fraction size, hypofractionated RT; shorter radiation schedules with decreased total dose and increased dose/fraction, has been investigated in large randomized trials in UK and Canada. These trials provided evidence for non-inferiority of hypofractionated RT regarding its efficacy and safety in early breast cancer. In high risk breast cancer, hypofractionated RT was found equivalent to conventional fractionation and of similar toxicities in a recent randomized phase III Chinese trial. In addition, hypofractionated RT offers the advantage of improving patients’ convenience, RT delivery resources maintenance and reducing treatment expenses. In our study, retrospective data were collected from records of patients diagnosed with node positive breast cancer between July 2011 and June 2014 and who received post-operative radiotherapy and were followed-up for ≥ 2 years. The aim of the study was to assess loco-regional recurrence and toxicity following different protocols of fractionation of postoperative RT.