Cimetidine and coumarin therapy of renal cell carcinoma. A pilot study.

Thirty-eight patients with metastatic renal-cell carcinoma (RCC) and 1 patient with a second primary RCC were treated with coumarin and cimetidine. Patients received 400 mg cimetidine p.o. daily and after 1 week 100 mg coumarin p.o. daily in addition until tumour progression. Two complete remission (30 and 50+ months) and 3 partial remissions (14, 13.8 months) could be achieved. Problems regarding possibly spontaneous regressions and comparable results of other treatment in RCC are discussed.