The histopathology of bronchogenic carcinoma and its relation to growth rate, metastasis, and prognosis

Abstract

During the course of a prospective study in which 6,136 older men were examined by photofluorogram and questionnaire every 6 months, 179 developed proved bronchogenic carcinoma. Histologic sections were obtained in 161 cases and classified by a panel of 3 pathologists using a modified World Health Organization classification. The panel agreed with the diagnoses made by the hospital pathologists in most of those originally classified as squamous cell or adenocarcinoma but classified 30% of the undifferentiated carcinomas as squamous cell tumors. The panelists placed most of these in the anaplastic subgroup (lc). Unanimity was highest for squamous cell carcinoma and within this group the extent of agreement was best for the most highly differentiated subgroup (la). Five-year survival rates were poor (10%), but equal for men with squamous cell and adenocarcinoma. These findings can be explained by the biologic character of the cancer types; squamous cell carcinomas have rapid growth rates and moderate metastatic potential, while adenocarcinomas have slow growth rates but high metastatic potential.