Trends in cancer incidence in Allegheny County, Pennsylvania, 1937-71.

Cancer incidence rates by race, sex, and cancer site were obtained from the Third National Cancer Survey for the years 1969-71 for residents of Allegheny County, Pennsylvania. When the sex-site-specific rates for 1969-71, as well as incidence rates from surveys in the county in 1937, 1947, and 1957-58, were compared with U.S. rates for 1937, 1947, and 1969-71, a number of significant changes in incidence were observed. Male incidence of cancers of the lung, bronchus, and trachea increased steadily between 1937 and 1969-71 both in Allegheny County and the United States. In the county, female incidence rates for these cancers decreased in the period 1947 to 1957-58 but showed an average annual increased of 9.2 percent in the interval 1957-58 to 1969-71. Incidence rates for county males increased by an average of 4.4 percent per year from 1957-58 to 1969-71. For stomach cancer, incidence rates for both sexes have decreased sharply in the county and in the United States. In the county, stomach cancer rates for females declined by an annual average of 4 percent from 1957-58 to 1969-71, while those formales dropped 2.1 percent. There appears to have been a steady decline over time in cervical cancer in Allegheny County, although the average annual rate of decrease of 2.8 percent for the latest interval (1957-58 to 1969-71) is not as large as the decrease of 3.9 percent per year from 1947 to 1957-58. Breast cancer rates for the county appear to have been steadily, although slowly, increasing at an average rate of about 0.6 percent per year, in contrast to almost constant U.S. rates. The county's breast cancer incidence rate for 1969-71 almost equals the U.S rate. There have been steady increases in prostate cancer incidence in both Allegheny County and the United States since 1937. For all sites combined, male cancer incidence rates increased, while those for females slowly decreased in both Allegheny County and the United States during the interval 1937 to 1969-71. In the county, male rates for the interval 1937 to 1969-71 increased an average of 1 percent per year, while female rates declined approximately 0.3 percent annually.