[Immune responses in broncho-pulmonary cancer]

The anti-tumoral immune response is essentially cellular and numerous studies have been conducted with the aim of augmenting it from the therapeutic aspect.

Activation of the immune system has been reported in the early stages of bronchial carcinoma. On the other hand numerous studies have demonstrated a degree of immuno-suppression in patients with advanced cancer prior to any immuno-suppressant treatment, particularly an alteration of cell mediated immunity. The presence of white cells, infiltrating the tumour is an indication of an active host response to the tumour. Several para-neoplastic syndromes associated with the presence of auto-antibodies have been described, particularly in small cell bronchial carcinoma. Other antibodies not associated with para-neoplastic syndromes have also been found, principally directed against the tumour suppressant gene P53. Non-specific active immuno-therapy (BCG, interferons, interleukins.), passive immuno-therapy (monoclonal antibodies) and adoptive immuno-therapy have been studied for many years without encouraging results. Specific active immuno-therapy (anti-tumour vaccines and gene therapy) is the route being most actively explored at present.

Correct targeting of patients likely to benefit from immuno-therapy, specificity and effectiveness of the agents, the expression of transfected genes and the risk of infection and dissemination during clinical trials are all problems currently under investigation.

Manipulations of the immune response have been and are being undertaken with the aim of improving its effectiveness. Anti-tumour vaccines and gene therapy are the routes most studied.