An experimental model of pleural cancer. Value of orthotopic implantation of human tumor tissue in nude mice]

Pleural cancers are tumours which are frequently refractory to all treatment. Faithful animal models (experimentally reproducing the human disease) are necessary to study the natural history of this disease and to test standard or experimental treatments. The athymic bald mouse is currently used for the construction of experimental models because it avoids immunological rejection. Initially murine models were constructed following subcutaneous injection of cloned cells then implantation of tumour fragments. The tumours obtained are not superimposable on the human disease in terms of local, regional or metastatic development and the results from these studies, using such models, are difficult to transpose to humans. It is possible to implant fragments of histologically intact human tumour into the pleura of bald mice. This orthoptic (site for site) transplantation enables one to obtain in the mouse a tumour which tends to conserve the biological characteristics of the original tumour and to develop locally, regionally and at distance in a fashion which is similar to the human disease. In spite of the inherent limits of immunotolerance of the host and thus difficulties of extrapolation to man, this review attempts to point out the place for these models and for an understanding of the therapy of pleural cancers.