Sequential hormone therapy for advanced breast cancer.

Abstract

Sequential hormone therapy for advanced breast cancer can offer significant and prolonged disease control with minimal morbidity. Predictors of response to sequential hormone therapy have not previously been identified. Sixty postmenopausal women with advanced or recurrent breast cancer treated with sequential megestrol acetate and tamoxifen were evaluated to identify factors which predict response to sequential therapy. The response rate to first-line therapy was 28% (17/60). Forty-seven percent of patients who responded to the first therapy responded to the second (8/17). Four of 16 patients (25%) who failed the first hormone therapy responded to the second. The response rate to a second hormone therapy was 25% (15/60). Chi-square tests were used to test the association between a response to sequential hormonal therapy and prior chemotherapy, age at first hormone trial, number of sites of disease, dominant site of disease, sequence of hormonal therapy, second response on the basis of first response, presence of soft tissue disease or bone disease alone, and receptor value. A one-tailed Fisher exact probability test revealed that a greater proportion of receptor-positive patients exhibited positive responses to sequential hormonal therapies than did receptor-negative patients. All of the patients who responded to a second hormonal therapy were estrogen receptor (ER)- and progestogen receptor (PgR)-positive. Fisher exact probability tests revealed a statistically significant association between response to initial hormone therapy and response to a subsequent hormone trial. This study suggests that patients who fail their initial hormone trial should be considered for a second hormonal trial if they are ER- and PR-positive.