Five-year quality-of-life results from a phase 3 trial of postmastectomy chest wall radiotherapy for breast cancer

The multinational SUPREMO trial reported adjuvant chest wall radiotherapy had no effect on 10-year overall survival (primary endpoint) in patients with intermediate-risk breast cancer after mastectomy. The quality-of-life (QOL) substudy of SUPREMO (UK patients only) examined the effects of chest wall radiotherapy. Five-year QOL results have now been published. Adult patients with intermediate-risk breast cancer who had undergone mastectomy and axillary surgery were randomized 1:1 to receive chest wall radiotherapy (40-50 Gy in 15-25 fractions) or no radiotherapy. Of the 989 UK patients consenting to the QOL substudy, 947 of 989 (96%) returned baseline questionnaires and 620 of 832 (75%) returned year-5 questionnaires. Chest wall symptoms were worse with chest wall radiotherapy (p=0.017) with improvement between years 1, 2 and 5. Chemotherapy was associated with less improvement over time (p=0.033) but without interaction with chest wall radiotherapy. No statistically significant differences were observed in other QOL domains (arm symptoms, body image, fatigue, pain, overall QOL, phsyical functioning, or anxiety and depression. In subgroup analyses, patients who had a sentinel lymph node biopsy followed up by an axillary lymph node clearance with chest wall radiotherapy had worse chest wall symptoms than those having a single axillary operation (p=0.0015). The authors conclude that the 5-year QOL findings showed worse chest wall toxicity and no effect on other QOL domains. Subgroup analyses suggested a potential negative effect of chemotherapy and axillary clearance after sentinel node biopsy.