Efficacy of UFT plus Tamoxifen for Estrogen-Receptor-Positive Breast Cancer and Tamoxifen plus UFT for Estrogen-Receptor-Negative Breast Cancer : Adjuvant Therapy after Administration of Mitomycin.

OBJECTIVE

We conducted a prospective multicentre, collaborative randomised study on postoperative adjuvant therapy in patients with stage II primary breast cancer to evaluate the effect of a combination of tegafur and uracil (UFT) on tamoxifen (TAM) plus mitomycin (MM) in patients with estrogen-receptor-positive [ER(+)] breast cancer and TAM on UFT + MM in patients with estrogen-receptor-negative [ER(-)] breast cancer.

METHODS

MM (13 mg/m(2)) was intravenously administered on the day of surgery for all patients, after which patients with ER(+) were randomised to TAM 20 mg/day (treatment A) or TAM 20 mg/day and UFT 400 mg/day (treatment B). Patients who were ER(-) were randomly allocated UFT 400 mg/day (treatment C) or TAM 20 mg/day and UFT 400 mg/day (treatment D). TAM and UFT were administered orally for 2 years, starting on day 14 after surgery.

ENDPOINTS

5-year disease-free survival (5y DFS), 5-year overall survival (5y OS), and safety.

RESULTS

The study commenced in November 1988 and the data cut-off was May 1997 after follow-up of the last patient for 5 years. A total of 765 patients with stage II breast cancer were enrolled. 436 patients with ER(+) [group A: 213, group B: 223] and 317 patients with ER(-) [group C: 162, group D: 155] breast cancer were eligible for this study. The rate of 5y DFS was 83.1% for group A and 90.7% for group B (p = 0.020). There was a significant difference in 5y DFS between the two groups among postmenopausal and positive lymph node metastases patients. The incidence of adverse reactions was 4% for group A and 18% for group B (p < 0.05). The rate of 5y DFS was 77.1% for group C and 85.5% for group D (p = 0.063). The rate of 5y OS was 84.7% for group C and 89.8% for group D (p = 0.216). The incidence of adverse reactions was 18% in group C and 11% in group D (p = 0.06).

CONCLUSION

UFT in combination with TAM + MM showed higher efficacy than TAM + MM as a postoperative combination therapy for breast cancer in patients with ER(+) breast cancer. A trend was observed in favour of the addition of TAM to UFT + MM in postmenopausal and lymph node metastases-negative patients with ER(-) breast cancer.