Epidemiology of oral cancer in Connecticut, 1935 to 1985.

All cases of oral cancer (N = 9708) recorded by the Connecticut Tumor Registry from 1935 to 1985 were analyzed for time-trend patterns within 10-year age-groups. Crude, age-specific, age-adjusted incidence rates and birth cohort analyses were calculated. The average annual age-adjusted incidence rate was 12.9/100,000 for men and 2.9/100,000 for women (1970 US standard million population). The male age-adjusted incidence rate decreased 33% from the late 1930s to the early 1980s. The female age-adjusted incidence rate exhibited a threefold steady increase over this same time period. The male/female ratio for oral cancer incidence declined dramatically from 10.4 to 2.7 for the age-adjusted rate, nearly a fourfold decrease during the 51- year period. Birth cohort analyses for women indicated a marked increase in oral cancer incidence for the birth cohort of 1900, which was sustained in the birth cohorts that followed. Birth cohort analyses for men revealed a decline in oral cancer incidence for birth cohorts born after 1910. The highest incidence rates were found in the urban counties and the lowest in the rural areas.