Changing patterns of lung cancer in the United States.

Although mortality from lung cancer increased throughout the United States during 1950-1975, the rate of change varied according to sex, race, and geographic sector. A pronounced shift in the geographic pattern of lung cancer was seen in white males. The elevation in rates in urban counties of the north in the 1950s faded over time and was not observed in the 1970s. The highest rates during 1970-1975 were in the south, both in rural and urban areas, particularly at younger ages. The sharpest rise in US mortality rates was reported among nonwhite males. Cohort analysis revealed that for males born before 1885 age-specific rates among whites exceeded those among nonwhites by nearly 50%, but for those born after 1915 a 50% excess was seen among nonwhites. Among nonwhite males the highest mortality in the 1970s occurred in urban areas of the south. Among females the rate of increase in lung cancer mortality was higher in the 1970s, but racial and geographic differences tended to be minor. Cigarette smoking accounts for a substantial part of the shifting patterns of lung cancer, but it is likely that other factors are involved, including industrial exposure (e.g., exposure to asbestos in shipyards during World War II) and possibly nutritional deficiencies and other determinants yet to be identified.