[Epidermoid bronchial cancer induced by radiotherapy]

The occurrence is reported of a bronchial epidermoid cancer appearing 13 years after irradiation for an intra-thoracic paraganglioma. Four criteria are required when considering the carcinogenic effects of radiation: a documented history or irradiation, a latent period of 8 to 20 years, histological evidence of the development of a malign tumor within the irradiated zone and a different histological type from that of the primary tumor. All these criteria are satisfied in this case. The occurrence of post radiation fibrosis and the knowledge of a cancer developing in primary or secondary pulmonary fibrosis are considered in discussing carcinogenesis. Radiation induces fibrous and an oncogenic mutation which by the secretion of certain proteins, notably a growth factor, favours the development of a cancer.