Immunocompetence and its modification after BCG immunotherapy in patients with colon carcinoma

The ability to develop cutaneous response to Mantoux, phytohemagglutinin (PHA) and dinitrochlorobenzene (DNCB) was studied in patients with carcinomas in the digestive tract, with particular emphasis on cancer of the colon, in patients with benign pathology and in a control group. The patients with a malignant disease in the digestive tract, considered as a group, showed a remarkable decrease of responses to Mantoux (31%), to PHA (21%) and to DNCB (58%) compared to the control group where incidence amounted to 61%, 73% and 100% respectively. The depression in the immune cellular response is more remarkable yet in colon carcinoma (Mantoux 11%, PHA 0%, DNCB 11%) all of which suggest that the impairment of the immune response depends on the tumor localization. An increase of unresponsiveness was also observed within the group with a benign pathology although the deterioration is lower than that observed in the malignant group. The patients with adenocarcinoma of the colon received BCG immunotherapy and the changes in cellular and humoral response were studied in them. Although the improving mechanism does not seem to affect simultaneously the various expressions of cell mediated immunity, a stimulating effect in the response was observed in what refers to recall antigen, inflammatory reaction and sensitization to DNCB. These changes ranked Mantoux greater than DNCB greater than PHA. There was a direct correlation between skin test reactivity to at least one antigen and the patient survival, but is not the case with the changes observed in the immunoglobulins level. The significance of these changes in relation to the possible anti-tumor effect is discussed.