Efficient reduction of loco-regional recurrences but no effect on mortality twenty years after postmastectomy radiation in premenopausal women with stage II breast cancer - A randomized trial from the South Sweden Breast Cancer Group

PurposeTo study long term loco-regional and distant recurrence rate and survival after post-mastectomy radiotherapy in combination with oral cyclophosphamide in premenopausal women with stage II breast cancer.Study designA three-armed randomized multicenter phase III trial comparing 1) Radiotherapy (RT) 2) RT+ oral cyclophosphamide for one year (RT + C) and 3) Oral cyclophosphamide only (C).Radiotherapy was administered, in 20 fractions, to 48 Gy to the axilla and parasternal lymph nodes, 45 Gy to infra- and supraclavicular fossae and 38 Gy to the chest wall. Cyclophosphamide was prescribed as 12 courses of 130 mg/m2 od for14 days every 4 weeks.Patients and methods367 patients from 15 surgical departments in Southern Sweden, representing 80% of all eligible patients, were included in the trial between 1978-1983. Median age was 47 years, median tumour size was 25 mm, and 33% of the patients were lymph node negative. Median follow-up time was 24 years.ResultsRT reduced the risk at twenty years for loco-regional recurrence in C-treated patients at twenty years with 75% (13.9% vs. 3.5%). The risk reduction was highly significant in both N0 and N+ patients. No reduction in systemic disease or mortality was observed.ConclusionPost-mastectomy radiotherapy reduced loco-regional recurrences in this premenopausal population, but no effect was seen on mortality with 20 years follow-up.