Adjuvant specific immunotherapy of resectable squamous cell lung carcinoma. Analysis at the eighth year

From June 1976 to June 1981, 86 patients with resectable (Stage I and II) squamous cell lung carcinoma were entered into a randomized controlled study with three arms: Control Group - no treatment postoperatively. Specific Immunotherapy Group - three monthly doses of 500 micrograms of tumor associated antigen (TAA) emulsified with complete Freund's adjuvant (CFA). Nonspecific Immunotherapy Group - three monthly doses of CFA emulsified in saline. All the patients in the study received skin tests with PPD (5TU) and 100 micrograms of the same TAA used for the immunotherapy at 1, 4, 6, 9, and 12 months postoperatively. Patients in both immunotherapy groups showed a tendency for a better disease-free interval and overall survival compared to those of the control, but these interval and beneficial therapeutic effects were statistically significant only in the Group III patients who had no hilar lymph node metastasis (T1N0 and T2N0). Although Group III was originally designated as a nonspecific immunotherapy group, retrospectively, it should be called a lowdose specific immunotherapy group because these patients actually received a total of 500 micrograms of TAA (as skin tests) and three doses of CFA at separate sites.