Quality of life after breast-conserving therapy and adjuvant radiotherapy for non-low-risk ductal carcinoma in situ (BIG 3-07/TROG 07.01): 2-year results of a randomised, controlled, phase 3 trial (original) (raw)

2020, The Lancet Oncology

Background BIG 3-07/TROG 07.01 is an international, multicentre, randomised, controlled, phase 3 trial evaluating tumour bed boost and hypofractionation in patients with non-low-risk ductal carcinoma in situ following breastconserving surgery and whole breast radiotherapy. Here, we report the effects of diagnosis and treatment on health-related quality of life (HRQOL) at 2 years. Methods The BIG 3-07/TROG 07.01 trial is ongoing at 118 hospitals in 11 countries. Women aged 18 years or older with completely excised non-low-risk ductal carcinoma in situ were randomly assigned, by use of a minimisation algorithm, to tumour bed boost or no tumour bed boost, following conventional whole breast radiotherapy or hypofractionated whole breast radiotherapy using one of three randomisation categories. Category A was a 4-arm randomisation of tumour bed boost versus no boost following conventional whole breast radiotherapy (50 Gy in 25 fractions over 5 weeks) versus hypofractionated whole breast radiotherapy (42•5 Gy in 16 fractions over 3•5 weeks). Category B was a 2-arm randomisation between tumour bed boost versus no boost following conventional whole breast radiotherapy, and category C was a 2-arm randomisation between tumour bed boost versus no boost following hypofractionated whole breast radiotherapy. Stratification factors were age at diagnosis, planned endocrine therapy, and treating centre. The primary endpoint, time to local recurrence, will be reported when participants have completed 5 years of follow-up. The HRQOL statistical analysis plan prespecified eight aspects of HRQOL, assessed by four questionnaires at baseline, end of treatment, and at 6, 12, and 24 months after radiotherapy: fatigue and physical functioning (EORTC QLQ-C30); cosmetic status, breast-specific symptoms, arm and shoulder functional status (Breast Cancer Treatment Outcome Scale); body image and sexuality (Body Image Scale); and perceived risk of invasive breast cancer (Cancer Worry Scale and a study-specific question). For each of these measures, tumour bed boost was compared with no boost, and conventional whole breast radiotherapy compared with hypofractionated whole breast radiotherapy, by use of generalised estimating equation models. Analyses were by intention to treat, with Hochberg adjustment for multiple testing. This trial is registered with ClinicalTrials.gov, NCT00470236.