Complete remission following endocrine or combined cytotoxic and hormonal treatment in advanced breast cancer. A retrospective analysis.

Among 422 patients with advanced breast cancer treated in a randomized trial we observed 60 complete responses (CR). Sixteen were achieved among 206 patients treated with endocrine therapy alone and 37 among 216 patients treated with concomitant chemotherapy and endocrine therapy. The incidence of CR in women treated with the concomitant modality was higher in those with dominant soft tissue disease, intermediate in those with osseous or pulmonary involvement, and low in patients with liver metastases. Bone was shown to be the organ most responsive to therapy among patients treated with hormonotherapy, while patients with soft tissue metastases had an unexpectedly low rate of complete remission with this modality. The probability of achieving a CR was inversely proportional to the tumor burden in the patients treated with concomitant chemotherapy and endocrine therapy. For complete responders on hormone treatment alone and for those on combined endocrine and cytotoxic therapy, both median time to progression (26 and 29 months, respectively) and survival (52 and 53 months, respectively) were similar and statistically significantly longer than in partial or minor responders. This observation leads us to the conclusion that the hormonal component is the determinant for the length of a CR.