[A randomized study of tumor resection versus mastectomy in breast cancer. 2. 6-year results of the DBCG-82TM (Danish Breast Cancer Cooperative Group) protocol]

Abstract

The Danish Breast Cancer Cooperative Group (DBCG) conducted a randomized trial to compare breast conservation with mastectomy in patients suffering from mammary carcinoma. From January 1983 to March 1989 the trial recruited a total of 1,153 women. Of these 905 patients (79%) were randomly assigned to one of two treatment options, whereas 248 patients (21%) refused randomization. Of the randomized patients, 90% received the surgical option to which they had been originally assigned. As regards breast conservation, the tumour was excised with the object of tumour-free margins on gross examination, and radiotherapy was administered subsequently to residual breast tissue. Mastectomy was performed as a modified radical procedure. The axilla was dissected in all instances. Patient and tumour characteristics were similar in the two random groups. The median follow-up time was 40 months. At 6 years of life table analysis the probability of recurrence free survival was 70% in the breast conservation group compared with 66% in the mastectomy group. Survival figures were 79% compared with 82%, respectively. Short-term follow-up did not disclose any significant difference between results of breast conservation compared with those of mastectomy. On the other hand, in the non-randomized group the patients undergoing breast conservation had a significantly poorer outcome than the patients treated with mastectomy.