Comparative effects of the administration period of adjuvant chemotherapy using doxifluridine (5'-DFUR) for 1 year versus 3 years after breast cancer surgery by the Shimane Breast Cancer Study Group.

Background: The present study investigated the efficacy of oral doxifluridine (5-DFUR) by comparing the survival between patients who received 5'-DFUR at 800 mg/body daily for 1 or 3 years after surgery for stage 1, 2 or 3 breast cancer. Patients and Methods: Ninety-two patients were enrolled from January 1995 to December 1997, of whom 87 were eligible. The patients were stratified into pre-menopausal and post-menopausal groups, and then each group was further stratified into 1-year or 3-year administration groups. All patients were given endocrine therapy, with gosereline acetate (3.6 mg/body, monthly) for the premenopausal patients and tamoxifen (20 mg/day, daily) for the post-menopausal patients for 3 years. Results: The median follow-up duration was 9.5 years. Although no differences were found in the overall or disease-free survivals between the administration groups, subset analysis demonstrated that, in the pre-menopausal patients, the 3-year administration group showed a significant higher overall survival rate than the 1-year administration group, but not in post-menopausal patients. A multivariate analysis also indicated that the administration duration of 5'-DFUR was a significant factor for disease-free survival. Conclusion: The present study supports the usefulness of 5-DFUR for adjuvant chemotherapy against breast cancer, especially for premenopausal patients: however, further clinical study with a much larger sample sae is necessary to reach a conclusive result.