[Successful treatment of metastatic renal cell carcinoma with cimetidine--report of two cases].

There has been no effective therapy for metastatic renal cell carcinoma (RCC). Cimetidine has been demonstrated to block histamine mediated activation of suppressor T cells in man and in animal models, resulting in an anti-tumor immune response. We treated two patients with cimetidine for matastatic RCC. Case 1: A 61-year-old man presented with a diagnosis of metastatic lung and brain tumor of RCC. Interferon therapy was not effective, but after radiation therapy, his brain metastasis revealed partial response. He received cimetidine 800 mg orally after radiation, his lung metastasis revealed almost complete response. But he died of ischemic heart disease. Case 2: A 58-year-old woman presented with a metastatic lung tumor of RCC. We started interferon therapy. But because of general fatigue and anemia, she required discontinution of interferon therapy. So she received cimetidine 800 mg orally and her lung metastasis revealed complete response. She remained well and had no evidence of disease. Patients with metastatic renal cell carcinoma can occasionally respond to cimetidine and further investigation must be studied.