High dose toremifene in advanced renal-cell carcinoma

Toremifene (Fareston) - a novel antiestrogenic drug with a triphenylethylene structure - is effective in the treatment of postmenopausal breast cancer patients. It can be safely given even at high doses of up to 300 mg/day, The purpose of the present study was to investigate the effect and tolerability of high-dose toremifene in the treatment of patients with advanced renal-cell carcinoma (RCC). A total of 36 patients started treatment with toremifene at 300 mg/day, including 26 men and 10 women. Their mean age was 56 years (range 35-75 years). In all, 19 patients were nephrectomized. One patient was not evaluable for response because of insufficient treatment time. The response rate was 17%, including one complete response (CR, 3%) lasting for 121+ weeks and five partial responses (PRs, 14%) with a mean duration of 40+ weeks. Ten cases of no change (NC, 28%) had a mean duration of 24 weeks. There was no significant difference in the response rate when patients with lung metastases alone were compared with patients showing metastases of other sites with or without lung metastases. Total pain control was achieved in 45% of the patients who had pain at the beginning of the treatment, and partial control was attained in 20%. Ten patients (28%) developed adverse reactions, which led to discontinuation of the treatment in one case. Blood samples were taken from 16 patients on days 0, 1, 3, 7, 14, and 28 for drug analyses. The concentration of toremifene and its main metabolites measured in serum were about 1.5 times that detected after a conventional dose of 60 mg/day. It can be concluded that high-dose toremifene is an effective and safe palliative treatment in advanced RCC.