Postoperative chemo-endocrine treatment with mitomycin C, tamoxifen, and UFT is effective for patients with premenopausal estrogen receptor-positive stage II breast cancer

The effectiveness of combining mitomycin C (MMC), tamoxifen (TAM), and 1-(2 -tetrahydrofuryl)-5-fluorouracil (tegafur) was evident in patients with est rogen receptor-positive (ER+) breast cancers. UFT, an oral preparation of t egafur and uracil at a molar ratio of 1:4, was reported to have higher anti tumor effects than tegafur alone for patients with breast cancer. Therefore , the combined chemotherapy of MMC, TAM and UFT may possibly be effective f or breast cancer. From 1988 to 1991, we studied the effects of postoperative adjuvant therapy for Japanese women with stage II breast cancer, all seen at 71 institution s in western areas of Japan. Five hundred and ninety four patients with sta ge II primary breast cancer who had undergone curative surgery, including t otal mastectomy and axillary lymph node dissection, were enrolled. On the d ay of surgery, each patient was given 13 mg/m(2) of MMC intravenously. Pati ents with ER+ tumors were then assigned to group A or group B. Group A rece ived 30 mg/day of TAM given orally from postoperative 2 weeks, for 2 years. Group B was additionally given an oral dose of 300 mg/day of UFT for 2 yea rs, given concomitantly with 30 mg/day of TAM. Patients with ER- tumors wer e assigned to group C or group D. Group C were prescribed 300 mg/day of UFT , orally, from postoperative 2 weeks for 2 years, and group D were addition ally given an oral dose of 30 mg/day of TAM together with 300 mg/day of UFT . There were no differences among the groups regarding prognostic factors or doses of MMC and TAM in ER+ patients and MMC and UFT in ER- patients. Toxic ity rates for leukopenia, anorexia, and nausea/vomiting were higher in grou p B than in group A patients. There were no statistical differences in the overall survival and disease-free survival times between groups A and B, or groups C and D, for all eligible cases. In a retrospective subgroup analys is using Bonferroni's adjustments, the additional effect of UFT on the comb ined treatment of MMC and TAM lengthened the disease-free survival time for patients with premenopausal ER+ cancers (corrected P value by Bonferroni's adjustments < 0.05). Multivariate analysis showed that effects of the comb ined treatment of MMC, TAM, and UFT was significantly related to the menopa usal status (P < 0.01). Our findings show that postoperative ingestion of MMC, TAM, and UFT was eff ective for patients with premenopausal ER+ stage II breast cancer.