Tolerance and outcome of hypofractionated post-mastectomy radiotherapy among elderly breast cancer patients in a specialized center in Nigeria

Background: The incidence of breast cancer rises dramatically with age, and numerous studies have reported the benefits of post mastectomy radiotherapy in both young and elderly breast cancer patients. The limited numbers of radiotherapy machines and the conventional fractionation schedule which are of long duration make access to radiotherapy more difficult especially among the elderly in Nigeria. Hypo fractionated radiotherapy offers an alternative option (with a shorter duration and comparable side effects and outcomes) to conventional radiotherapy as reported in western literatures. Such studies are grossly lacking in a sub-Saharan African country like Nigeria, hence the need for this study. Methods: In this retrospective study, the records of 83 elderly patients with stages II and III breast cancer that were treated with radiotherapy in the Radiotherapy and Oncology Department of UDUTH, Sokoto, Nigeria, from January 2015 to February 2019 were evaluated. Radiotherapy was given at a dose of 45 Gy in 18 fractions of 2.5 Gy to the chest wall and the regional lymph nodes over a period of 3.5 weeks. The end point was freedom from any grade 3 or higher toxicities and disease free survival at 2 years. Results: Majority, 67 (80.7%) of the 83 patients had invasive ductal carcinoma which were not otherwise specific. About two-thirds of the patients (69.9%) had the disease located in the right breast. After a 24 month follow up, there were no grade 3 or 4 toxicities. Forty-two (50.6%) and 16 (19.2%) patients had grade 2 skin and nausea/vomiting toxicities respectively. Eighty (96.4%) were disease free at 24 months, 3 (3.6%) patients had local recurrence, while 1 (1.2%) had distant metastasis to the lungs. The two years overall survival rate was 90%. Conclusions: Hypofractionated radiotherapy in elderly breast cancer patients proved to be comparable to conventional radiotherapy in terms of toxicities and outcome in our center.