The importance of tamoxifen to a cisplatin-containing regimen in the treatment of metastatic melanoma.

The combination of dacarbazine (DTIC, 220 mg/m2) and cisplatin (DDP, 25 mg/m2) IV daily for 3 days every 3 weeks, carmustine (BCNU, 150 mg/m2) IV every 6 weeks, and tamoxifen (TAM, 10 mg orally twice daily) produced a 50% objective response rate in patients with metastatic melanoma. Associated with this treatment, there was a high incidence of deep venous thrombosis (DVT) and pulmonary embolism (PE). In an effort to reduce this toxicity, this regimen minus TAM was studied, and the results are reported. Twenty of twenty patients are evaluable for response and toxicity. There was one complete response (CR) lasting 5+ months and one partial response (PR) lasting 4+ months for an overall response rate of 10% (95% confidence limits, 1.23% to 31.70%). Two patients exhibited a mixed response and three patients developed disease stabilization lasting 4 to 10 months. Toxicity was similar to the original study except that no patients developed DVT or PE. This statistically significant (Fisher's exact test [two-tail] P = 0.008) decrease in the response rate by comparison with that achieved with the TAM-containing regimen may signal an essential role of TAM in this regimen. TAM may be acting in synergy with cisplatin through its calcium channel-blocking properties. TAM should be included as described in the initial reports, and the patients should be carefully observed for vascular complications.