THE MAGNITUDE OF THE PROBLEM

No nationwide cancer registry exists; therefore, the incidence of cancer is estimated on the basis of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database, which tabulates cancer incidence and death figures from nine sites, accounting for about 10% of the U.S. population, and from population data from the Bureau of the Census. In 2004, 1.36 million new cases of invasive cancer (699,560 men, 668,470 women) were diagnosed and 563,700 persons (290,890 men, 272,810 women) died from cancer. The percent distribution of new cancer cases and cancer deaths by site for men and women are shown in Table 66-1. Cancer incidence has been declining by about 2% each year since 1992.

The most significant risk factor for cancer overall is age; two-thirds of all cases were in those over age 65. Cancer incidence increases as the third, fourth, or fifth power of age in different sites. For the interval between birth and age 39, 1 in 72 men and 1 in 51 women will develop cancer; for the interval between ages 40 and 59, 1 in 12 men and 1 in 11 women will develop cancer; and for the interval between ages 60 and 79, 1 in 3 men and 1 in 5 women will develop cancer.

Cancer is the second leading cause of death behind heart disease. Deaths from heart disease have declined 45% in the United States since 1950 and continue to decline. After a 70-year period of increases, cancer deaths began to decline in 1997 (Fig. 66-1). The five leading causes of cancer deaths are shown for various populations in Table 66-2. Along with the decrease in incidence has come an increase in survival for cancer patients. The 5-year survival for white patients was 39% in 1960-1963 and 64% in 1992-1998. Cancers are more often deadly in blacks; the 5-year survival was 53% for the 1992-1998 interval. Incidence and mortality vary among racial and ethnic groups (Table 66-3). The basis for these differences is unclear.