May 27 (HealthDay News) -- Adding paclitaxel to standard chemotherapy improved disease-free survival in women with early-stage breast cancer, a Spanish study finds.

The phase III trial included 1,246 women with early, non-metastatic breast cancer who were randomly assigned to receive treatment with fluorouracil, epirubicin, and cyclophosphamide (FEC), or FEC followed by weekly paclitaxel (FEC-P).

The estimated five-year survival rate in the FEC-P group was 78.5 percent, compared to 72.1 percent in the FEC group. The study also found a trend toward improved overall survival, but it didn't reach statistical significance.

"Because distant relapse-free survival is usually associated with overall survival, a statistically significant benefit in overall survival may become evident with a more protracted follow-up," wrote Dr. Miguel Martin, of the Spanish Breast Cancer Research Group.

In a retrospective analysis of the data, the researchers weren't able to identify a subgroup of patients who were more likely to respond to paclitaxel therapy on the basis of their tumor's expression of the estrogen receptor and HER2.

The study was published in the May 27 online issue of the Journal of the National Cancer Institute.

In an accompanying editorial, researchers at Memorial Sloan-Kettering Cancer Center in New York City reviewed several trials that examined the effects of adding taxanes (a family of drugs that include paclitaxel) to existing adjuvant therapy for breast cancer.

In that regard, the study by the Spanish team is important, because it was well-designed and used a good regimen and schedule of drugs, noted Dr. Clifford Hudis and Dr. Chau Dang.

SOURCE: Journal of the National Cancer Institute, news release, May 27, 2008