Randomized clinical trial of tamoxifen alone or combined with fluoxymesterone in postmenopausal women with metastatic breast cancer.

A randomized clinical trial was performed to determine if combination hormonal therapy with tamoxifen (TAM) and fluoxymesterone (FLU) was more efficacious than TAM alone for the treatment of postmenopausal women with metastatic breast cancer. Patients failing TAM could subsequently receive FLU. The dose of both drugs was 10 mg orally twice daily. Objective responses were seen in 50 of 119 TAM patients (42%) and 63 of 119 TAM plus FLU patients (53%) (one-sided P = .05). Time to disease progression distributions were better for TAM plus FLU (median, 350 days v 199 days), but the log rank test only approached statistical significance (one-sided P = .07). Duration of response and survival distributions were similar between the two treatment arms. Toxicities, in terms of androgenic side effects, were greater on the TAM plus FLU regimen. Fifty-two patients are evaluable for response with FLU following TAM and 21 (40%) have achieved a response. We conclude that the advantages in terms of response rate and time to progression observed with TAM plus FLU probably represent a biological effect, but are not of sufficient magnitude to justify the routine clinical use of this combination given the lack of survival advantage and side effects encountered.