Objective: Trends in cancer mortality, cardiovascular mortality, and cancer incidence are assessed among US whites to determine whether aging of the population and smoking patterns completely account for increased cancer rates from 1973 through 1987.
Design: For mortality, percentage changes in age-specific rates were calculated. For cancer incidence, trends in age-specific rates across time periods and birth cohorts were assessed for several sites.
Main outcome measures: National US cardiovascular and cancer mortality rates and incidence rates for smoking-related cancer, breast cancer, and all other types of cancer in 10% of the US population covered by the National Cancer Institute's Surveillance, Epidemiology, and End Results Program were analyzed.
Results: From 1973 through 1987, cardiovascular mortality decreased 42% in the age group 0 to 54 years and decreased 33% in the age group 55 to 84 years; concurrently, cancer mortality decreased 17% in the younger group but increased 12% in the older group. By 1987, even though proportionally fewer people in the older age groups died, relatively more of them died of cancer. Men born in the 1940s had twice as much cancer as those born in 1888 through 1897 and more than twice as much cancer not linked to smoking; women born during this period had 50% and 30% more of these same cancers, respectively. Rates of smoking-related cancers in recent cohorts of women were five to six times greater than in those born in 1888 through 1897, while rates in men declined. Recent cohorts of women also had more than twice as much breast cancer as those born in 1888 through 1897.
Conclusions: In recent US birth cohorts, our model found that increases in cancer have occurred that are not solely linked to aging of the population and smoking patterns. In light of these results and similar findings in Sweden, changes in carcinogenic hazards in addition to smoking are likely to have occurred and need to be studied further.