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Competing Interests: Disclosures of potential conflicts of interest may be found at the end of this article.

Objectives: We examined the prevalence of endoscopy (sigmoidoscopy or colonoscopy) by indication and by demographic and lifestyle factors., Methods: We analyzed cross-sectional data collected in 1997 from participants aged 50 years and older in the Cancer Prevention Study (CPS) II Nutrition Cohort., Results: Fifty-eight percent of men and 51% of women reported ever having undergone endoscopy; only 42% of men and 31% of women reported endoscopy for screening rather than for disease diagnosis or follow-up. Prevalence varied by demographic and lifestyle factors., Conclusions: Efforts to increase colorectal cancer screening need to target women, all persons aged 50-64 years, and those with colorectal cancer risk factors. Future studies should distinguish endoscopy for screening from procedures for disease diagnosis and follow-up to avoid overestimating screening compliance.

Multivitamins contain several nutrients, including folic acid, that are hypothesized to reduce the risk of colorectal cancer. Previous studies suggest that multivitamin use may reduce colorectal cancer risk but only after a long latency period. The authors examined the association between regular multivitamin use (four or more times per week) and colorectal cancer incidence among 145,260 men and women in the Cancer Prevention Study II Nutrition Cohort. Current multivitamin use was reported on a questionnaire at enrollment in 1992-1993. All participants had also reported multivitamin use on a questionnaire completed for a different study approximately 10 years earlier (in 1982). The authors observed 797 incident cases of colorectal cancer during follow-up from 1992 to 1997. After multivariate adjustment, regular multivitamin use at enrollment was not associated with risk of colorectal cancer (rate ratio = 1.04, 95% confidence interval: 0.87, 1.23), whereas regular multivitamin use 10 years before enrollment was associated with reduced risk (rate ratio = 0.71, 95% confidence interval: 0.57, 0.89). Regular multivitamin users 10 years before enrollment were at similarly reduced risk whether they were still regular multivitamin users at enrollment or had stopped. These results are consistent with the hypothesis that past, but not recent, multivitamin use may be associated with modestly reduced risk of colorectal cancer.

Objective: Calcium, vitamin D, and dairy product intake may reduce the risk of colorectal cancer. We therefore examined the association between these factors and risk of colorectal cancer in a large prospective cohort of United States men and women., Methods: Participants in the Cancer Prevention Study II Nutrition Cohort completed a detailed questionnaire on diet, medical history, and lifestyle in 1992-93. After excluding participants with a history of cancer or incomplete dietary information, 60,866 men and 66,883 women remained for analysis. During follow-up through 31 August 1997 we documented 421 and 262 cases of incident colorectal cancers among men and women, respectively. Multivariate-adjusted rate ratios (RR) were calculated using Cox proportional hazards models., Results: Total calcium intake (from diet and supplements) was associated with marginally lower colorectal cancer risk in men and women (RR = 0.87, 95% CI 0.67-1.12, highest vs lowest quintiles, p trend = 0.02). The association was strongest for calcium from supplements (RR = 0.69, 95% CI 0.49-0.96 for > or = 500 mg/day vs none). Total vitamin D intake (from diet and multivitamins) was also inversely associated with risk of colorectal cancer, particularly among men (RR = 0.71, 95% CI 0.51-0.98, p trend = 0.02). Dairy product intake was not related to overall risk., Conclusions: Our results support the hypothesis that calcium modestly reduces risk of colorectal cancer. Vitamin D was associated with reduced risk of colorectal cancer only in men.

Background: Although effective screening for colorectal cancer (CRC) exists, only 37% of incident CRC are diagnosed at a localized stage at which treatment is effective. We identified demographic and other characteristics of adults (> or = 50 years old) who reported no CRC screening., Methods: We calculated the prevalence of never having had a fecal occult blood test and/or a sigmoidoscopy or colonoscopy by age, sex, and other factors using the 1999 Behavioral Risk Factor Surveillance System data., Results: CRC screening tests were underutilized across all segments of the population. Underutilization was highest in persons aged 50-64 years and those with lower education and a lack of health insurance and preventive services., Conclusions: The data indicate that large proportions of average-risk adults across various sociodemographics and behavioral factors are not utilizing recommended CRC screening tests. There is a need to increase the awareness of the importance of utilizing effective CRC screening tests for the early detection of colorectal cancers.

Context Consumption of red and processed meat has been associated with colorectal cancer in many but not all epidemiological studies; few studies have examined risk in relation to long-term meat intake or the association of meat with rectal cancer. Objective To examine the relationship between recent and long-term meat consumption and the risk of incident colon and rectal cancer. Design, Setting, and Participants A cohort of 148 610 adults aged 50 to 74 years (median, 63 years), residing in 21 states with population-based cancer registries, who provided information on meat consumption in 1982 and again in 1992/1993 when enrolled in the Cancer Prevention Study II (CPS II) Nutrition Cohort. Follow-up from time of enrollment in 1992/1993 through August 31, 2001, identified 1667 incident colorectal cancers. Participants contributed person-years at risk until death or a diagnosis of colon or rectal cancer. Main Outcome Measure Incidence rate ratio (RR) of colon and rectal cancer. Results High intake of red and processed meat reported in 1992/1993 was associated with higher risk of colon cancer after adjusting for age and energy intake but not after further adjustment for body mass index, cigarette smoking, and other covariates. When long-term consumption was considered, persons in the highest tertile of consumption in both 1982 and 1992/1993 had higher risk of distal colon cancer associated with processed meat (RR, 1.50; 95% confidence interval [CI], 1.04-2.17), and ratio of red meat to poultry and fish (RR, 1.53; 95% CI, 1.08-2.18) relative to those persons in the lowest tertile at both time points. Long-term consumption of poultry and fish was inversely associated with risk of both proximal and distal colon cancer. High consumption of red meat reported in 1992/1993 was associated with higher risk of rectal cancer (RR, 1.71; 95% CI, 1.15-2.52; P = .007 for trend), as was high consumption reported in both 1982 and 1992/1993 (RR, 1.43; 95% CI, 1.00-2.05). Conclusions O... [ABSTRACT FROM AUTHOR]