Quality of life results of BIG 02-04 MRC EORTC SUPREMO trial of chest wall radiotherapy in patients with intermediate risk stage II breast cancer after mastectomy

Background: BIG2-04 MRC/EORTC SUPREMO is an international randomised phase III trial assessing chest-wall irradiation in women with intermediate risk breast cancer following mastectomy (ISRCTN61145589). Patients were prospectively randomized to receive chest-wall radiotherapy or not. The primary endpoint is overall survival (OS at 10 years) with secondary endpoints of chest-wall/regional recurrence, disease-free survival, quality of life (QOL) and cost-effectiveness. The first OS analysis will be at 300 events (deaths). Here we report QOL results at 2 years. Method: Between April 2007 and May 2013 the trial recruited 1688 patients internationally; 990 were eligible for the QOL study (UK centres only). Patients completed the EORTC QLQ-C30 and BR23 questionnaires, Hospital Anxiety and Depression Scale (HADS) and EQ5D at baseline (pre-randomisation), 1 and 2 years. 947 patients (96%) returned the baseline questionnaires, 85% year 1 and 81% year 2 questionnaires. Repeated mixed effects methods were used to analyse the data, with baseline score and age included as covariates in the model. SAS's PROC MIXED was utilised due to its ability to deal with data missing at random. Results: Patients randomised to radiotherapy reported worse chest-wall symptoms (pain, swelling, oversensitivity and skin problems in the “area of the affected breast”) (p = 0.013), although an improvement in symptoms was seen between year 1 and 2 post-randomisation (p = 0.009). No significant between-group differences were observed for arm symptoms, body image, fatigue, pain, overall QOL, physical functioning or HADS scores. An age effect was found: younger patients reported significantly worse chest-wall (p = 0.0004) and arm symptoms (p = 0.005), body image problems (p = 0.0007) and anxiety (p = 0.0015). Conclusion: Chest wall radiotherapy led to more chest wall symptoms up to 2 years post-randomisation, but reassuringly there was no impact on arm symptoms, body image, overall QOL and patient functioning for this group. However, worse QOL seen in younger women will need further investigation.