Annual report to the nation on the status of cancer, 1975-2006, featuring colorectal cancer trends and impact of interventions (risk factors, screening, and treatment) to reduce future rates

Abstract

Background: The American Cancer Society, the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR) collaborate annually to provide updated information regarding cancer occurrence and trends in the United States. This year's report includes trends in colorectal cancer (CRC) incidence and death rates and highlights the use of microsimulation modeling as a tool for interpreting past trends and projecting future trends to assist in cancer control planning and policy decisions.

Methods: Information regarding invasive cancers was obtained from the NCI, CDC, and NAACCR; and information on deaths was obtained from the CDC's National Center for Health Statistics. Annual percentage changes in the age-standardized incidence and death rates (based on the year 2000 US population standard) for all cancers combined and for the top 15 cancers were estimated by joinpoint analysis of long-term trends (1975-2006) and for short-term fixed-interval trends (1997-2006). All statistical tests were 2-sided.

Results: Both incidence and death rates from all cancers combined significantly declined (P < .05) in the most recent time period for men and women overall and for most racial and ethnic populations. These decreases were driven largely by declines in both incidence and death rates for the 3 most common cancers in men (ie, lung and prostate cancers and CRC) and for 2 of the 3 leading cancers in women (ie, breast cancer and CRC). The long-term trends for lung cancer mortality in women had smaller and smaller increases until 2003, when there was a change to a nonsignificant decline. Microsimulation modeling demonstrates that declines in CRC death rates are consistent with a relatively large contribution from screening and with a smaller but demonstrable impact of risk factor reductions and improved treatments. These declines are projected to continue if risk factor modification, screening, and treatment remain at current rates, but they could be accelerated further with favorable trends in risk factors and higher utilization of screening and optimal treatment.

Conclusions: Although the decrease in overall cancer incidence and death rates is encouraging, rising incidence and mortality for some cancers are of concern.

Figure 1

Natural History and Interventions on colorectal Cancer

Figure 2

Figure 2A. Colorectal Cancer Age-Standardized Incidence Rates by Stage at Diagnosis SEER 9 Incidence, 1975–2006, All Races, Both Sexes Figure 2B. Colorectal Cancer 5-year Relative Survival Rates by Stage at Diagnosis SEER 9 Incidence, 1975–2001, All Races, Both Sexes Source: SEER 9 areas (San Francisco, connecticut, Detroit, Hawaii, Iowa, New Mexico, Seattle, Utah and Atlanta). Incidence rates are age-adjusted to the 2000 US Std Population (19 age groups - Census P25-1103). Regression lines with up to 4 Joinpoints are calculated using the Joinpoint Regression Program Version 3.3.1, April 2008, National Cancer Institute. Stage analyses were based on SEER historic stage categories using extent of Disease codes and the Collaborative Stage Data Collection system. Relative survival was calculated with the SEER*stat software (www.seer.cancer.gov/seerstat) version 6.5.2: NCI; 2009.

Figure 3

Partition of Past Trends in Colorectal Cancer Incidence* (1975–2000) * Rates are based on the first primary colorectal cancer and include the primary sites of C18.0 C18.2–C18.9, C19.9, C20.9 and the ICD-03 histologies of: 8000–8001, 8010, 8020, 8140, 8210–8211. Rates do not include cases that are form a reporting source of death certificate only or autopsy only.

Figure 4

Partition of Past Trends in Colorectal Cancer Mortality (1975–2000) Source: CDC National Center for Health Statistics (NCHS) National Vital Statistics System. Heron M, Hoyert DL, Murphy SL, Xu J, Kochanek KD, Tejada-Vera B. Deaths: Final data for 2006. National Vital Statistics Reports, Apr 17, 2009; 57(14).

Figure 5

Projections of Colorectal Cancer Mortality with Differing Intensities of Cancer Control (2000–2020) Source: CDC National Center for Health Statistics (NCHS) National Vital Statistics System. Heron M, Hoyert DL, Murphy SL, Xu J, Kochanek KD, Tejada-Vera B. Deaths: Final data for 2006. National Vital Statistics Reports, Apr 17, 2009; 57(14).

Figure 6

Contributions of Risk Factors, Screening and Treatment to Optimistic Projections of Colorectal Cancer Mortality (2000 – 2020) Source: CDC National Center for Health Statistics (NCHS) National Vital Statistics System. Heron M, Hoyert DL, Murphy SL, Xu J, Kochanek KD, Tejada-Vera B. Deaths: Final data for 2006. National Vital Statistics Reports, Apr 17, 2009; 57(14).