Hypofractionated irradiation in 794 elderly breast cancer patients: An observational study

To assess the efficacy, and the acute and late toxicity of hypofractionated radiotherapy (Hypo-RT), and the impact of age and comorbidities on disease progression and death in elderly breast cancer (BC) patients. Women aged ≥65 years who received Hypo-RT (42.4 Gy in 16 fractions, plus a boost for high-risk patients) were considered for the present analysis. Competing risk analysis was used to estimate the 5-year cumulative incidence of BC progression and BC-related death, calculating the adjusted subhazard ratios (SHR) with 95% confidence intervals (95%CI) in relation to age, hypertension-augmented Charlson Comorbidity Index (hCCI), tumor characteristics, and chemotherapy. The sample included 794 patients with a median age of 74 years (range 65-91 years). At the baseline, 70% of these patients had at least one comorbidity. With a median follow-up of 48.3 months, the 5-year cumulative incidence of BC progression and BC-related death was 6.7% (95%CI 4.8%-9.2%) and 2.3% (95%CI 1.2%-3.9%), respectively. Old age (≥80 years) and a high burden of comorbidity (hCCI ≥ 2) were independently associated with BC progression. Hypo-RT is safe in elderly BC patients, but age and comorbidities influence BC progression. Further studies are warranted.