Colorectal cancer incidence in the United states, 1999-2004

Background: By using recent national cancer surveillance data, the authors investigated colorectal cancer (CRC) incidence by subpopulation to inform the discussion of demographic-based CRC guidelines. METHODS: Data included CRC incidence (1999-2004) from the combined National Program of Cancer Registries and Surveillance, Epidemiology, and End Results Program databases. Incidence rates (age-specific and age-adjusted to the 2000 US standard population) were reported among individuals ages 40 to 44 years, 45 to 49 years, 50 to 64 years, and ≥65 years by sex, subsite, disease stage, race, and ethnicity. Rate ratios (RR) and rate differences (RD) were calculated to compare CRC rates in different subpopulations. RESULTS: Incidence rates were greater among men compared with women and among blacks compared with whites and other races. Incidence rates among Asians/Pacific Islanders (APIs), American Indians/Alaska Natives (AI/ANs), and Hispanics consistently were lower than among whites and non-Hispanics. Sex disparities were greatest in the population aged ≥65 years, whereas racial disparities were more pronounced in the population aged <65 years. Although the RD between blacks and whites diminished at older ages, the RD between APIs and whites, between AI/ANs and whites, and between non-Hispanics and Hispanics increased with increasing age. By subsite, blacks had the highest incidence rates compared with whites and other races in the proximal and distal colon; the reverse was true in the rectum. By stage, whites had higher incidence rates than blacks and other races for localized and regional disease; for distant and unstaged disease, blacks had higher incidence rates than whites. CONCLUSIONS: The current findings suggested differences that can be considered in formulating targeted screening and other public health strategies to reduce disparities in CRC incidence in the United States.