SURAMIN IN ADRENOCORTICAL CANCER - LIMITED EFFICACY AND SERIOUS TOXICITY

OBJECTIVE No satisfactory treatment for adrenocortical carcinoma (ACO) is available. We investigated the efficacy and toxicity of suramin in the treatment of metastatic ACC since suramin has been recently reported to be active as a single agent therapy for patients with ACC and prostatic carcinoma. DESIGN We collected data on 9 patients with metastatic ACC treated with suramin in four centres in Germany between 1987 and 1992. PATIENTS Nine patients (5 women, 4 men; age range 32-67 years) were included. Biochemical evidence of steroid excess was found in 6/9, in three leading to clinical symptoms (hypertension, hyperglycaemia, hirsutism, gynaecomastia). MEASUREMENTS Tumour responses were assessed by radiological and biochemical evaluation. Other investigations included regular measurements of blood cell counts, coagulation, hepatic and renal function parameters, and serum suramin concentrations. RESULTS The patients received; cumulative doses ranging from 8.2 to 30.2 g suramin over periods of 1-15 months. 3/9 achieved a partial response, 2/9 disease stabilization and 4/9 experienced progressive disease. Tumour responses were transient. Suramin treatment was without direct influence on steroid excess. Serious side-effects included coagulopathy (6/9), thrombocytopenia (6/9), polyneuropathy (2/9) and allergic skin reactions (4/9); the death of two patients was possibly related to suramin therapy. Both toxicity and tumour response were strongly associated with serum level or cumulative dose of suramin. CONCLUSIONS (1) Suramin is of antineoplastic efficacy in the treatment of metastatic adrenocortical carcinoma. (2) The clinical use of suramin is limited by a narrow therapeutic window with the risk of serious and possibly lethal toxicity at one extreme, and loss of efficacy at the other. Strict monitoring of suramin serum levels is mandatory aiming at levels between 200 and 250 mg/l. Suramin should not be considered as first-line treatment for metastatic adrenocortical carcinoma. (3) To improve treatment options in adrenocortical carcinoma as well as for further investigation on the usefulness of suramin, controlled prospective trials are urgently needed.