Immunochemotherapy of lung cancer.

After surgical resection of their primary lung cancer, 33 patients were randomized into one of three groups. The first received high-dose methotrexate once per month with citrovorum rescue, for 3 months. The second group were immunized monthly with a homogenate of Freund's complete adjuvant and carefully characterized soluble antigen derived from allogeneic lung cancer cells of appropriate histology, for 3 months. The third group received a combination of methotrexate and immunization monthly, for 3 months. Each patient was monitored immunologically before, during, and after the treatment period, by use of delayed hypersensitivity reactions to recall and cancer antigens, in vitro lymphocyte response to mitogens, and mixed lymphocyte blocking factor activity. The group that received methotrexate showed little change in skin reactivity, a reduction of blocking factor activity, and significant rebound overshoot in in vitro lymphocyte performance. The immunized group showed a tendency to production of blocking factor activity, striking conversion and enhancement of skin reactivity, and little change in in vitro lymphocyte performance. The immunochemotherapy group showed dramatic increases in specific skin reactivity to cancer antigens, up to 2 years after treatment, in vitro lymphocyte rebound overshoot, and reduction of blocking factor activity production. Classic life table analysis of the probability of freedom from metastases in patients with stage-I cancer indicate that the disease-free interval in patients who received methotrexate is longer than in historic and concomitant controls but not as long as in those who received immunization. The best group appear to be those who received combination immunochemotherapy. We emphasize that the small numbers in this pilot study do not yet allow firm conclusions to be made.