The changing histopathology of primitive lung cancer.

This study was performed on 1710 lung epithelial malignant tumours, diagnosed in the biennia 1963/1964 (42 cases), 1973/ 1974 (293), 1983/1984 (637) and 1993/1994 (738). It was aimed at evaluating whether, over a time span that long, the distribution of the histopathological patterns could have changed. The neoplasms were classified according to the WHO criteria (1981). From our data, a striking increase becomes apparent for all histotypes. Squamous cell carcinoma holds the leading position both among males and females, even though its rate of increase tends to slow down among males. Analogous trend is observed for all the other histotypes but adenocarcinoma. Among females, the rate of increase continues to accelerate for all histotypes but large cell carcinoma. The male to female ratio is ranging from 2:6 for adenocarcinomas to 12:1 for squamous cell carcinomas. In conclusion, impressive changes seem to have occurred in the frequency of the different lung oncotypes over this time span, especially for adenocarcinoma (increasing trend) and large cell carcinoma (decreasing trend). It also seems worth underlying that the marked increase among females could make lung carcinoma the number one cause of cancer-related deaths in this sex.