Levamisole in advanced human breast cancer.
A clinical trial of levamisole, an orally effective modifier of the immune response, is reported in women with primary inoperable breast cancer (stage III). After being rendered clinically disease-free by radiotherapy to the breast, supraclavicular area, and axilla, patients were allocated alternately to a control group (no further treatment) and a levamisole-treated group (150 mg orally three times a week on alternate weeks) and were followed-up by physical examination and laboratory tests. In 43 patients (23 control and 20 levamisole), there was significant prolongation of the median disease-free interval (25 v. 9 months) and survival (90% v. 35% alive at 30 months) in the levamisole-treated group compared with the controls. Levamisole treatment was also associated with an increase in the percentage and intensity of delayed hypersensitivity skin reactions and in the absolute lymphocyte-counts. No significant toxicity of levamisole was observed.