Surveillance, epidemiology, and end results lung cancer data applied to the World Health Organization's classifications of lung tumors.

Less than 1% of the lung cancer cases from the Surveillance, Epidemiology, and End Results (SEER) Program changed categories as a result of the World Health Organization's revision of histologic classifications of lung tumors. Of the 28,119 microscopically proved lung cancers reported to SEER in 1977-79, 32% were squamous cell carcinoma, 16% were small cell and/or oat cell carcinoma, 27% were adenocarcinoma, 8% were large cell carcinoma, and 5% were other specified types. A further 12% (approximately 3,500 cases) were reported with such nonspecific terms as bronchogenic carcinoma, carcinoma of the lung, and undifferentiated or anaplastic carcinoma. The magnitude of the use of these nonspecific terms showed the need for greater precision in reporting and recording data.