Response to tamoxifen and fluoxymesterone in a group of breast cancer patients with disease recurrence after cessation of adjuvant tamoxifen.

The response to tamoxifen or a combination of tamoxifen and fluoxymesterone was assessed in 54 postmenopausal breast cancer patients with recurrent disease. The patients had originally been entered in a randomized trial of 2 years of tamoxifen (40 mg daily), as an adjunct to primary surgery, versus no adjuvant endocrine therapy. The objective response rate (complete + partial) to the mentioned salvage endocrine therapies was significantly lower among patients from the tamoxifen group as compared to the controls (14% vs 54%; P less than 0.01). Their median time to disease progression was also significantly shorter (4 vs 15 months; P less than 0.05). Differences between the groups in regard to prognostic factors could not explain these differences. The lower response rate to these endocrine treatments was possibly one reason for the poorer survival outlook after relapse observed among the patients previously treated with adjuvant tamoxifen. An increased relapse-free survival achieved with adjuvant therapy may thus to some extent be offset by a poorer survival after relapse.