Background: Lung cancer is the most common cause of cancer death in the United States, and its incidence has been rising for at least 50 years. Shifts in histologic type and differences in sex and race distribution have accompanied the increased incidence of lung malignancies.
Methods: Population-based data regarding lung cancer reported to the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program for the 15-year period 1973-1987 were analyzed.
Results: Results indicate that from 1973-1977 to 1983-1987, the age-adjusted rates of lung cancer increased by 30%, with the gain markedly greater in women (70%) than in men (17%). The largest percentage increases in age-adjusted rates were observed for small cell carcinoma and adenocarcinoma (approximately 60% each), with a more modest change for squamous cell carcinoma (+ 14%). For squamous cell carcinoma, the age-adjusted rates increased substantially for black (65%) and white (70%) women and only slightly for black men (10%), whereas it decreased slightly in recent years for white men.
Conclusions: In recent years, adenocarcinoma has replaced squamous cell carcinoma as the most frequent histologic subtype for all sexes and races combined. These shifts in histologic types by sex and race may be related to differences in exposure to tobacco products, dietary factors, environmental or occupational carcinogens, and host characteristics. Increased use of transbronchial and needle biopsy may have also influenced these trends to some extent. Over the study period, 5-year relative survival rate did not change appreciably for lung cancer, suggesting that therapeutic advances have had little effect.