The treatment outcome of patients undergoing breast-conserving therapy: the clinical role of postoperative radiotherapy.

BACKGROUND: Treatment outcome was evaluated in patients who underwent breast-conserving therapy and tangential irradiation. After verifying background factors including systemic therapy, the clinical efficacy of postoperative irradiation was investigated. METHOD: There were 708 study subjects, all of whom had early breast cancer treated between 1992 and 2002. The median follow-up period was 83 months. After breast-conserving surgery, in patients with negative surgical margins, only tangential irradiation at 48 Gy/24 fr was performed. In contrast, in those with positive surgical margins, 10 Gy of radiation boost to the tumor bed with electrons was administered after tangential irradiation with 50 Gy/25 fr. Treatment outcome was analyzed using the Kaplan-Meier method and Cox's proportional hazards regression model. RESULTS: The disease-free survival and no-recurrence rates within the ipsilateral breast after 5 years were 93.4 and 97.2%, respectively. Risk factors for recurrence within the ipsilateral breast included younger age of patient, the number of positive lymph nodes, and no endocrine therapy. However, the surgical margin was not a risk factor. Risk factors for relapse outwith the ipsilateral breast included younger age, the number of positive lymph nodes, and recurrence within the ipsilateral breast. CONCLUSIONS: From our analysis of 708 Japanese women who received breast-conserving therapy, which can be regarded as a standard method in Japan, the treatment outcome was compatible with previous reports from other countries.

[Assessment of post-administration body distribution of toremifene and tamoxifen, and their administration regimens].

Toremifene is an anti-estrogenic drug like tamoxifen. We assessed the body distributions after administration of toremifene and tamoxifen in order to evaluate their treatment regimens by measuring the concentrations in tissues. It is known that, after toremifene (TOR) or tamoxifen (TAM) is consecutively administered to breast cancer patients, TOR or TAM and their main active N-desmethyl-metabolites (TOR-1 or TAM-1) are detected in sera, tumor tissues, and lymph nodes. Accordingly, after we administered toremifene or tamoxifen to primary breast cancer patients previous to surgery, we measured the concentrations of TOR, TOR-1, TAM, TAM-1 in sera, tumor tissues, and lymph nodes. We found that the concentrations of TOR and TOR-1 in sera, tumors, and lymph nodes reached a peak about 2 weeks after administration of toremifene 40 mg. Likewise, the concentrations of TAM and TAM-1 in sera, tumors, and lymph nodes reached a peak about 2 weeks after administration of tamoxifen, although the peak levels were lower than those of TOR or TOR-1. The concentrations of TAM-1 in lymph nodes were significantly and positively correlated to the duration of administration of TAM, and it was predicted that the concentration of TAM-1 in lymph nodes would reach a steady state at more than 4 weeks after administration of tamoxifen. The concentrations of TOR and TOR-1 were higher in tumors and lymph nodes than in sera. Furthermore, the concentrations of TOR and TOR-1 were significantly higher than those of TAM and TAM-1 in sera and tumors, respectively. Moreover, the concentration in tissue increased in a dose-dependent manner with administration of toremifene 120 mg. There were no significant differences between breast cancers positive and negative for estrogen receptors, with regard to the concentrations of TOR and TOR-1 in either sera, tumors, or lymph nodes. In conclusion, it would be expected that treatment with toremifene might be more effective for breast cancer than that with tamoxifen.