Randomized clinical trial of cyclophosphamide, 5-FU, and prednisone with or without tamoxifen in postmenopausal women with advanced breast cancer

The purpose of this study was to determine if tamoxifen added to the efficacy of a CFP (cyclophosphamide, 5-FU, and prednisone) regimen. One hundred thirty-one postmenopausal women with advanced breast cancer without prior chemotherapy exposure were randomized to receive CFP alone or combined with tamoxifen; six were disqualified because of ineligibility. Objective responses were seen in 68% of the eligible patients receiving CFP and in 61% of those receiving CFP plus tamoxifen. Median times to progression were 287 days for CFP and 158 days for CFP plus tamoxifen (two-sided log-rank test of equality of progression distributions, P = 0.07). Median survival times were 544 days for CFP and 394 for CFP plus tamoxifen (two-sided log-rank test of equality of survival distributions, P = 0.08, after adjustment for stratification factors using the Cox model, two-sided P = 0.14). The addition of tamoxifen to CFP was not associated with longer time to progression or survival in any Cox covariate model. On the basis of our data, it can be concluded that the addition of tamoxifen to CFP does not substantially improve either the time to disease progression or survival in women with metastatic breast cancer.