Tamoxifen in high-risk premenopausal women with primary breast cancer receiving adjuvant chemotherapy. Report from the Danish Breast Cancer Co-Operative Group DBCG 82B trial

Following modified radical mastectomy, pre- and perimenopausal (amenorrhoea for <5 years) patients with stage II or III breast cancer received CMF (cy clophosphamide 600, methotrexate 40, 5-fluorouracil 600 mg/m(2) intravenous ly (i.v.) every 4 weeks, 9 cycles). The effect on recurrence-free survival (RFS) and overall survival (OS) of the addition of adjuvant tamoxifen (TAM) to adjuvant chemotherapy was examined by randomisation either to no additi onal treatment (n=314), or concurrently TAM 30 mg daily for 1 year (n = 320 ). 40% had positive, 12% negative and 48% unknown receptor status. One year after surgery 21% versus 35% (CMF + TAM versus CMF) were still menstruatin g (P < 0.01). With a median follow-up of 12.2 years there was no difference in RFS (10-year RFS 34% versus 35%, P = 0.81) or OS (45% versus 46%, P = 0 .73). In a Cox proportional hazards model, tumour size, number of metastati c lymph nodes, frequency of metastatic nodes in relation to total number of nodes removed, degree of anaplasia, age, and menostasia within the first y ear after operation were significant independent prognostic factors for RFS , and the same factors except age for OS. No significant interactions with TAM were seen. Thus, in this group of pre- and perimenopausal highrisk earl y breast cancer patients with heterogeneous receptor status given CMF i.v., concurrent TAM for 1 year did not improve the outcome. These results do no t exclude that receptor positive patients may benefit from adjuvant TAM for longer periods given sequentially to chemotherapy. (C) 1999 Elsevier Scien ce Ltd. All rights reserved.