Therapeutic effects of hydroxyurea. Experience with 118 patients with inoperable solid tumors.

Abstract

Hydroxyurea (Hydrea, Squibb) has proved to be a drug with moderate anticancer chemotherapeutic value which may be taken on an ambulatory basis with minimal clinical toxicity. One hundred and eighteen patients with inoperable neoplasms were treated with hydroxyurea on an outpatient basis, receiving an average oral dose of 50 mg/kg body weight daily in 2 divided doses. A reduction of 25% or more in tumor size was considered an objective response. As with other anticancer agents, the response of different neoplasms to hydroxyurea was variable. Patients with malignant melanomas, cancer of the colon, rectum, and anus (particularly with metastasis to the liver), cancer of the head and neck, lymphomas, and primary hepatomas responded best. Patients with carcinoma of the prostate, thyroid, or lung and those with primary cancer in an unknown site responded the poorest. Of 10 patients with sarcoma, 60% had subjective relief, and 37% had objective improvement. One patient with ovarian cancer, of 7 treated, has remained asymptomatic with no evidence of dissemination for over 2 years on hydroxyurea therapy; and one patient with cancer of the kidney, of 4 treated, had a dramatic response of metastases to bone. The toxicity in most instances was mild and consisted primarily of hematopoietic depression which usually cleared up spontaneously in one to two weeks after withdrawal of the drug. A continuous oral dose of 50 mg/kg body weight daily, in 2 divided doses, proved to be a satisfactory regimen.