Tuberculosis and lung cancer. An interesting case study.

This report describes the case of a patient with lung cancer who completely recovered when he was suffering from tuberculosis. Since bacillus Calmette-Guerin (BCG) has beneficial effects in certain types of cancer, it was hypothesized that infection with Mycobacterium tuberculosis induced an effective response against the tumour. M. tuberculosis-infected blood T-lymphocytes of the patient were cultured with two lung tumour cell lines. T-lymphocytes in vitro remained attached to tumour cells that appeared reduced in number. Moreover, M. tuberculosis isolated from the patient was a strong inducer, in infected macrophages, of the expression of the inducible form of the nitric oxide synthase, that may regulate cytotoxic activity of human macrophages.