[Bronchus cancer: pathologic-anatomic principles].

The various types of bronchial carcinoma are derived from pluripotent precursor cells of the respiratory epithelium. The direction of tumor differentiation depends on the locus of the genic mutation and therefore on the cancerogenic substance, on epigenetic gene amplification, and on autocrine regulations of the tumor cell population. The growth rate is the resultant of cell proliferation and cell loss by apoptosis. The formation of metastasis is determined by surface properties and implantation ability of the tumor cells. Age and state of lymph nodes are only loosely correlated with the biological behaviour of the tumors. It is possible to check the proliferative capacity of an individual tumor by immunocytochemistry and cytophotometry before any operative therapy. The extend of the preneoplastic lesions of the bronchial epithelium outside of the bronchial tumor, however, remains unknown. This explains why programs of early detection of bronchial cancer could not really improve long time survival and why surgical resection remain a palliative measure in most if not all cases.