Evaluation of paclitaxel in adjuvant chemotherapy for patients with operable breast cancer: preliminary data of a prospective randomized trial

Abstract

Purpose: Paclitaxel has significant antitumor activity in patients with metastaticbreast cancer who have been previously treated with or exposed to anthracycline-containing chemotherapy. In this prospective randomized trial, the role of paclitaxel was evaluated in an adjuvant setting to determine its impact on reducing the risk of recurrence in patients with operable breast cancer.

Experimental design: Five hundred twenty-four patients were randomized to be treated either with 4 cycles of paclitaxel followed by 4 cycles of combination therapy with 5-fluorouracil, Adriamycin, and cyclophosphamide (Pac/FAC) or with 8 cycles of FAC alone. Patients with intact primary breast cancer received the initial 4 cycles of paclitaxel or 4 cycles of FAC in a neoadjuvant setting. Planned duration of therapy was the same in all patients. After completion of 8 cycles of chemotherapy, those patients who were > or =50 years and whose tumors were positive for estrogen receptors received tamoxifen for 5 years.

Results: Ninety-two patients have had a recurrence after a median follow-up of 60 months with a range of 5-89 months. Estimated disease-free survival at 48 months was 0.83 for FAC and 0.86 for Pac/FAC group. The difference between the two groups was not statistically significant (P = 0.09). The overall estimated hazard ratio for Pac/FAC compared with FAC derived by fitting the Cox regression model and incorporating terms for prognostic factors was 0.66.

Conclusion: Preliminary results suggest that the addition of paclitaxel to a FAC regimen of adjuvant or neoadjuvant therapy may further reduce the risk of disease recurrence; however, differences were not statistically significant. At the time of this analysis, there have been 47 deaths. The survival data are too preliminary to permit meaningful evaluation of the impact of paclitaxel on mortality.