A coded study of antitumor immunity to human lung cancer assayed by tube leukocyte adherence inhibition

The present study was undertaken to evaluate the specificity of antitumor immunity to human lung cancer, measured by an in vitro assay--tube leukocyte adherence inhibition (LAI). We standardized and monitored the putative tumor antigen activity of the extracts by testing leukocytes from controls and patients with lung cancer in the Montreal General Hospital. A specific antitumor response to a lung cancer antigen was detected with coded leukocytes from 56% (20 out of 36) of patients with epidermoid lung cancer. By contrast, 4% (2 out of 53) of patients with inflammatory lung disease and none of 46 other patients with cancer metastatic to the lung or with other diagnoses had an LAI-positive result. The LAI response was inversely related to the extent of cancer: 80% (8 of 10) with Stage I, 66% (2 of 3) with Stage II, 54% (6 of 11) with localized Stage III, and 33% (4 of 12) with widespread Stage III were LAI positive. Leukocytes from patients with epidermoid, adenocarcinoma, or small cell lung cancer reacted to a common tumor antigen shared by extracts of epidermoid and small cell lung cancer. This study with coded samples from a remote hospital confirms the results of other investigators that the LAI measures an antitumor immune response to human organ-specific neoantigens.