A randomized clinical study of immunotherapy in lung cancer is done to study its therapeutic and immunologic effects. Locally far advanced lung cancer (conventionally thought to be inoperable) is removed by a radical lung resection to remove all visible tumor. Post operatively one group of patients will receive immunotherapy with fresh autologous tumor vaccine. Autologous tumor cell suspension is first treated by vibrio cholera neuraminidase, and then by concanavalin A. These tumor cells are injected to the patients, intradermally and subcutaneously together with complete Freund's adjuvant. The effects of the therapy are studied by various tests of cellular immunity such as, skin tests, T-B lymphocyte count, lymphocyte stimulation, migration inhibition test, cytotoxicity test. At the same time, studies of lung cancer specific antigen are to be carried out.