Locally advanced breast cancer: long-term results of a randomized trial comparing primary treatment with tamoxifen or radiotherapy in post-menopausal women

We have previously reported the early results of a randomized cross-over study of radical radiotherapy vs tamoxifen in patients with locally advanced breast cancer. This study has now recruited 143 patients with a median time from randomization of almost 10 years for both groups. Seventy-three patients received 20 mg tamoxifen twice daily, and 70 had primary radiotherapy at a dose of 40 Gy, which is a lower dose than currently administered. The treatment groups were similar in age, size of tumour and oestrogen receptor status. There was no significant difference between the two treatment groups for the combined initial response and static disease rates (89% for radiotherapy and 78% for tamoxifen, P=0.15). The median duration of initial response was 12 months for both groups. When patients crossed over to the alternative therapy on local relapse, there was no difference in response/static disease rates (P=0.34) and duration of response (P=0.76). A non-significant prolongation of the metastatic-free interval in favour of tamoxifen (P=0.08) was identified, although there was no difference in survival outcome (P=0.38). This study shows that in this group of patients primary tamoxifen offers a similar clinical benefit to primary radiotherapy at a dose of 40 Gy, and is therefore an acceptable alternative primary treatment.