Velikova G, et al. - In women with intermediate-risk breast cancer, researchers evaluated the impacts of postmastectomy radiotherapy on quality of life (QOL). Up to 2 years post-randomization, more local (chest wall) symptoms were seen among patients who received postmastectomy radiotherapy vs those who did not receive radiotherapy, but the difference between groups was minor.

Methods

• Researchers assessed 2-year QOL results (a prespecified secondary endpoint) of SUPREMO, which is an open-label, international, parallel-group, randomized, controlled trial.
• Either chest wall radiotherapy (50 Gy in 25 fractions or a radiobiologically equivalent dose of 45 Gy in 20 fractions or 40 Gy in 15 fractions) or no radiotherapy was randomly (1:1) received by women 18 years or older with intermediate-risk breast cancer (defined as pT1–2N1; pT3N0; or pT2N0 if also grade III or with lymphovascular invasion) who had a mastectomy and, if node positive, axillary surgery.
• Permuted blocks of varying block length were used for randomization, which was stratified by center, without masking of patients or investigators.
• Ten-year overall survival was the primary endpoint.
• Researchers performed this QOL substudy, which was open to all UK patients; they assessed questionnaires (European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-BR23, Body Image Scale, Hospital Anxiety and Depression Scale [HADS], and EQ-5D-3L) completed before randomization, and at 1, 2, 5, and 10 years.
• Global QOL, fatigue, physical function, chest wall symptoms, shoulder and arm symptoms, body image, and anxiety and depression were assessed as prespecified primary outcomes within this QOL substudy.
• Using repeated mixed-effects methods, intention to treat data analysis was performed.

Results

• Enrollment of 1,688 patients, internationally, as well as random assignment to chest wall radiotherapy (n=853) or no radiotherapy (n=835) was done between August 4, 2006 and April 29, 2013.
• Consent to participate in the QOL substudy was given by 989 (79%) of 1,258 patients from 111 UK centers (487 in the radiotherapy group and 502 in the no radiotherapy group); of those, baseline questionnaires were returned by 947 and these were included in the analysis (radiotherapy, n=471; no radiotherapy, n=476).
• The radiotherapy group vs the no radiotherapy group had worse chest wall symptoms at up to 2 years (mean score 14,1 [SD 15,8] in the radiotherapy group vs 11,6 [14,6] in the no radiotherapy group; effect estimate 2,17, 95% CI 0,40–3,94; p=0,016); however, an improvement was seen in both groups between years 1 and 2 (visit effect −1,34, 95% CI −2,36 to −0,31; p=0,010).
• Between treatment groups, arm and shoulder symptoms, body image, fatigue, overall QOL, physical function, or anxiety or depression scores were not different.