Histologic typing of lung cancer in Louisiana.

To determine whether histologic patterns differed in the high- and low-lung cancer mortality parishes (counties) of Louisiana and whether the findings in the state differed from those in other parts of the United States, we studied the available histopathologic materials for 272 persons of the 815 who died of lung cancer in ten southern, nonurban Louisiana parishes during a seven-year period from 1971–1977. Squamous-cell carcinoma and small-cell anaplastic carcinoma were the most common tumor types, closely followed in frequency by adenocarcinoma, confirming reports by other investigators of a change during the past decade in the prevalence of various histopathologic types of lung cancer. The distribution of histopathologic types was not different for high- and low-mortality parishes but differed significantly from other areas of the U. S. Three persons had diagnoses consistent with pleural mesothelioma. Occupational histories obtained from relatives showed that one of those persons was a homemaker and the other two were sugarcane farmers with no discernable exposure to asbestos.