Adjuvant chemotherapy with doxorubicin and dacarbazine has no effect in recurrence-free survival of malignant phyllodes tumors of the breast.

The purpose of this study was to evaluate the role of adjuvant chemotherapy in malignant phyllodes tumors of the breast treated at the Instituto Nacional de Cancerología of Mexico. Twenty-eight patients with malignant phyllodes tumors of the breast enrolled in a observational study from January 1993 to December 2003 to receive four cycles of adjuvant chemotherapy with doxorubicin 65 mg/m(2) over 48 hours intravenous infusion and dacarbazine 960 mg/m(2) over 48 hours intravenous infusion (n = 17) versus observation (n = 11). All patients had surgical resection, and 38% had an axillary dissection. Seven patients (25%) received adjuvant radiotherapy. Log-rank test was used to test for differences in recurrence-free survival (RFS). The median patient age was 42 years (range, 23-76 years). The median tumor size was 13 cm (range, 3-30 cm), and 46% of the tumors were in the left breast. At a median follow-up of 15 months (range, 2-81 months), there were seven recurrences and five deaths. The 5 year RFS rate was 58% (95% CI = 36% and 92%) for the patients who received adjuvant therapy and 86% (95% CI = 63% and 100%) for the patients who did not (p = 0.17). The median survival after recurrence was 6.5 months. Adjuvant chemotherapy with doxorubicin and dacarbazine did not affect patient survival. Future studies to identify relevant molecular targets should be implemented in order to define effective therapies for phyllodes tumors of the breast.