Possible adverse effect of failed adjuvant chemotherapy on the prognosis of women receiving consecutive chemotherapy for recurrent breast cancer.

This study tried to evaluate the impact of adjuvant chemotherapy on the induction of chemoresistance in radically operated upon breast cancer patients. Remission rate, remission duration and survival of a group of women (n = 22) treated with combination chemotherapy (adriamycin and cyclophosphamide, AC) for recurrent breast cancer after failed adjuvant therapy (cyclophosphamide, methotrexate, fluorouracil, vinblastine) were retrospectively compared with the clinical data of non-pre-treated patients (n = 28) receiving the same regimen (AC). The two groups of patients were comparable with regard to their risk factors. In the group of women with prior adjuvant chemotherapy only 3 out of 22 had a partial response, lasting 3, 8, and 16 months; the median survival was 50 months. In the group without prior adjuvant therapy 3 complete and 7 partial remissions with a median remission duration of 15.5 months (range 2-54 months) were found; the median survival was 104 months. The percentage of objective responses among the non-pre-treated patients at 36% was almost significantly higher than that of the pretreated women with 14% (p less than 0.1). Responders to chemotherapy after relapse profited in terms of survival within the first 3 years after radical mastectomy, although no statistically significant difference was observed. The survival data shown assume a "shifting" of women from a group with better prognosis to a group with unfavourable prognosis following failed adjuvant chemotherapy.