Abstract
A long-term multicentre double-blind study was designed to test the immunotropic effects of levamisole in patients undergoing operation for primary bronchial carcinoma. They received levamisole 50 mg three times a day by mouth or placebo for three days every fortnight, starting three days before surgery. Unless there was clinical evidence of recurrence, cytostatic drugs, corticosteroids, and radiotherapy were prohibited. In the 111 patients who have been followed up for one year the incidence of side effects was similar in both groups. Recurrences occurred in 10 out of 51 patients (seven deaths) receiving levamisole and in 20 out of 60 (12 deaths) receiving placebo. Further analysis showed that there were fewer recurrences on levamisole in patients with squamous cell carcinomas and medium and large primary tumours and fewer suspected and proved recurrences and deaths from metastases on levamisole in patients with extended tumours. Distant recurrences tended to be less common with levamisole, whereas the disease-free interval in relapsing patients was almost identical in the two groups. These interim results show that levamisole seems to exert its beneficial effect by preventing immunosuppression due to surgery.