No abstract

The incidence and risk of second primary cancers associated with tamoxifen therapy is low. The potential benefit of adjuvant tamoxifen therapy in breast cancer patients outweighs the risk of second primary cancers for Japanese breast cancer patients.

This study clarified the difference in the effects on serum lipids between toremifene (TOR) and tamoxifen (TAM). To remove influencing factors, we investigated adjuvant therapy for hormone receptor-positive patients with breast cancer without lymph node metastasis. The subjects were 65 patients who were enrolled in a multicenter randomized comparative study between April 1997 and March 2001. As adjuvant therapy, 20 mg of TAM or 40 mg of TOR was administered for 1 year. The levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A-1 (Apo A-1), apolipoprotein A(Apo B), and lipoprotein a (Lp(a)) were measured prior to administration and 3, 6, and 12 months after the start of administration. TC, LDL-C, Lp(a) and Apo B significantly decreased from the third month of administration compared with values before the start of administration in both the TOR and TAM groups. HDL-C significantly increased from the third month only in the TOR group. TG significantly increased in the TAM group but significantly decreased in the TOR group in the 12th month of administration. When these two groups were compared, HDL-C was significantly higher (p < 0.01) and TG was significantly lower (p < 0.01) in the TOR group in the 12th month. Improvement of abnormal values of TG, HDL-C and LDL-C was better in the TOR group than in the TAM group after administration for 12 months. The effect on lipid metabolism showed different profiles between the two selective estrogen receptor modulators (SERMs), and TOR gave better results than TAM.

Clinical trials conducted in Western countries have shown that aromatase inhibitors are associated with better disease-free survival (DFS) than tamoxifen in postmenopausal early breast cancer. Because pharmacogenetic differences in drug-metabolizing genes may cause ethnic differences, assessment of the efficacy and tolerability of aromatase inhibitors in non-white women is warranted. This open-label, randomized clinical trial included 706 postmenopausal Japanese women with hormone-receptor-positive breast cancer, who had received tamoxifen for 1 to 4 years as adjuvant therapy. This study was closed early after entry of approximately 28% of the initially planned patients. They were randomly assigned to either switch to anastrozole or to continue tamoxifen for total treatment duration of 5 years. Primary endpoints were DFS and adverse events. At a median follow-up of 42 months, the unadjusted hazard ratio was 0.69 (95% confidence interval, 0.42-1.14; P = 0.14) for DFS and 0.54 (95% CI, 0.29-1.02; P = 0.06) for relapse-free survival (RFS), both in favor of anastrozole. The incidence of thromboembolic events in the tamoxifen group and bone fractures in the anastrozole group was not excessively high. Switching from tamoxifen to anastrozole was likely to decrease disease recurrence in postmenopausal Japanese breast cancer patients. Ethnic differences in major adverse events may be attributable to a low baseline risk of these events in Japanese.

BACKGROUND: It has been reported that treatment with uracil-tegafur (UFT) has shown significantly better survival and relapse-free survival (RFS) than surgery alone. Therefore, we compared UFT with a combination therapy of cyclophosphamide, methotrexate, and fluorouracil (CMF) in patients who had undergone curative surgery for axillary lymph node-positive breast cancer. METHODS: A total of 377 node-positive patients with stage I, II, or IIIA disease were registered from September 1996 through July 2000 and were randomly assigned to either 6 cycles of CMF or 2 years of UFT. In both arms, tamoxifen (TAM) was concurrently administered for 2 years. The primary end point in this study was the non-inferiority of UFT to CMF. RESULTS: No statistically significant difference between the two groups was observed with regard to the 5-year RFS rate (72.2% in the UFT and 76.3% in the CMF). Adverse event profiles differed between the two groups, with a significantly lower incidence of leukopenia and anaemia in the UFT group, as well as anorexia, nausea/vomiting, stomatitis, and alopecia, which have implications for quality of life. CONCLUSION: UFT administered in combination with TAM holds promise in the treatment of lymph node-positive early breast cancer. On stratified analysis, the recurrence rate in the UFT group was found to be better in oestrogen receptor (ER)-positive patients. Tegafur-based treatment should be evaluated by a prospective randomised trial conducted in ER-positive patients.