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Purpose: Excess dietary fat consumption is strongly associated with the risk of colorectal cancer, but less is known about its role in the earliest stages of carcinogenesis, particularly within the proximal colon. In the following case-control study, we evaluated the relationship between the intake of dietary fats and the frequency of early proximal neoplasia [aberrant crypt foci (ACF) or polyps], detectable by high-definition colonoscopy with contrast dye-spray., Methods: Average-risk screening individuals underwent a high-definition colonoscopy procedure as part of larger ongoing clinical study of precancerous lesions in the proximal colon. Dietary fat intake was assessed using the Block Brief Food Frequency Questionnaire, which estimates average dietary intake based on 70 food items. The diets of individuals with no endoscopically identifiable lesions (n = 36) were compared to those with either ACF or polyps detected in the proximal colon., Results: In multivariate analysis, high dietary intake of total polyunsaturated fatty acids (PUFAs) and intake of omega-6 and omega-3 fatty acids were positively associated with neoplastic lesions in the proximal colon. When comparing ACF and polyp groups separately, a positive association was observed for both proximal polyps (OR 2.28; CI 1.16-7.09) and ACF (OR 2.86; CI 1.16-7.09) for total PUFA intake. Furthermore, the prevalence of proximal ACF was increased with higher intake of omega-6 (OR 3.54; CI 1.32-9.47) and omega-3 fatty acids (OR 2.29; CI 1.02-5.13), although there was no discernible difference in the omega-6/omega-3 ratio., Conclusions: These results suggest that dietary PUFAs may be positively associated with risk of early neoplasia in the proximal colon. This study provides further evidence that dietary PUFA composition may play an important role in altering the microenvironment within the human colon.

Purpose: Prospective cohort studies suggest that red and processed meat consumption is associated with increased risk of pancreatic cancer among men, but not women. However, evidence is limited, and less evidence exists for other types of meat., Methods: Cox proportional hazards regression was used to estimate multivariable-adjusted hazard ratios (HR) for the association of meat consumption, by type, with pancreatic cancer risk among 138,266 men and women in the Cancer Prevention Study-II Nutrition Cohort. Diet was assessed at baseline in 1992, and 10 years earlier, at enrollment into the parent CPS-II mortality cohort. 1,156 pancreatic cancers were verified through 2013., Results: Red meat, processed meat, and fish intake at baseline were not associated with pancreatic cancer risk. However, for long-term red and processed meat consumption (highest quartiles in 1982 and 1992, vs. lowest quartiles), risk appeared different in men [hazard ratio (HR) 1.32, 95% confidence interval (CI) 0.90, 1.95] and women (HR 0.72, 95% CI 0.47, 1.10, p heterogeneity by sex = 0.05). Poultry consumption in 1992 was associated with increased pancreatic cancer risk (HR 1.27, 95% CI 1.04, 1.55, p trend = 0.01, top vs. bottom quintile)., Conclusions: The associations of meat consumption with pancreatic cancer risk remain unclear and further research, particularly of long-term intake, is warranted.

Background: Birth characteristics and adult hormone concentrations influence breast cancer risk, but little is known about the influence of birth characteristics on hormone concentrations, particularly during adolescence., Methods: We evaluated the association of birth characteristics (birth weight, birth length, and gestational age) with serum sex hormone concentrations during late childhood and adolescence in 278 female participants of the Dietary Intervention Study in Children. Repeated measures analysis of variance models were used to assess the relationships of birth characteristics and serum estrogens and androgens at five different time points over a mean period of 7 years., Results: In analyses that did not take into account time from blood draw until menarche, birth weight was inversely associated with pre-menarche concentrations of estradiol, estrone sulfate, androstenedione, testosterone, and dehydroepiandrosterone sulfate (DHEAS). In the post-menarche analyses, birth weight was not significantly associated with concentration of any of the hormones under investigation. Birth length and gestational age were not associated with hormone concentrations before or after menarche., Conclusion: Birth weight is inversely associated with sex hormone concentrations before menarche in the model unadjusted for time from blood draw until menarche., Impact: The in utero environment has long-term influences on the hormonal milieu, which could potentially contribute to breast cancer risk.

Objective: To examine whether birth weight, birth length, and gestational age are individually associated with age at menarche., Methods: Analyses were conducted using data from n = 278 female participants in the Dietary Intervention Study in Children (DISC). Age at menarche was prospectively collected as part of the original DISC investigation. DISC participants self-reported birth weight, birth length, and gestational age with assistance from their mothers and other records as part of the DISC06 Follow-up Study at ages 25-29. Linear regression was used to estimate the association of birth characteristics and age at menarche., Results: Birth weight was positively associated with age at menarche (p

Background: The objective of this investigation was to evaluate the association between toenail selenium concentration and lung cancer risk in male smokers., Methods: We conducted a nested case-control study within the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study cohort. This substudy included 250 randomly selected incident lung cancer cases and 250 controls matched on age (up to +/- 5 years), intervention group assignment, and date of randomization (+/- 15 days). Odds ratios (ORs) and 95% confidence intervals (CIs) were determined using conditional logistic regression methods. Finland began fortification of agricultural fertilizers in the fall of 1984, increasing the dietary intake, plasma, and toenail selenium concentrations for the population. The present analyses were based on the calculated residual of toenail selenium after regressing it on date of randomization. The selenium residual and the interaction of the residual with date of randomization were included in models with smoking status and body mass index as covariates., Results: We observed a suggestion of a protective association for higher selenium status among men who entered the trial early (when the range of selenium values included very low levels). The OR for men with adjusted toenail selenium concentrations at the 75th percentile compared to those with the lowest selenium concentrations ranged between 0.20 (0.09-0.44) for men randomized earliest in the trial and 0.61 (0.27-1.41) for men randomized in the fifth year., Conclusions: These results suggest that low selenium status may be associated with increased risk for lung cancer.

Background: Some epidemiological investigations suggest that higher intake or biochemical status of vitamin E and beta-carotene might be associated with reduced risk of colorectal cancer., Methods: We tested the effects of alpha-tocopherol and beta-carotene supplementation on the incidence of colorectal cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, a double-blind, placebo-controlled trial among 29,133 50-69-year-old male cigarette smokers. Participants were randomly assigned to receive alpha-tocopherol (50 mg), beta-carotene (20 mg), both agents, or a placebo daily for 5-8 years. Incident colorectal cancers (n = 135) were identified through the nationwide cancer registry, and 99% were histologically confirmed. Intervention effects were evaluated using survival analysis and proportional hazards models., Results: Colorectal cancer incidence was somewhat lower in the alpha-tocopherol arm compared to the no alpha-tocopherol arm, but this finding was not statistically significant (relative risk (RR) = 0.78, 95% confidence interval (CI) 0.55-1.09; log-rank test p = 0.15). Beta-carotene had no effect on colorectal cancer incidence (RR = 1.05, 95% CI 0.75-1.47; log-rank test p = 0.78). There was no interaction between the two substances., Conclusion: Our study found no evidence of a beneficial or harmful effect for beta-carotene in colorectal cancer in older male smokers, but does provide suggestive evidence that vitamin E supplementation may have had a modest preventive effect. The latter finding is in accord with previous research linking higher vitamin E status to reduced colorectal cancer risk.

Objectives: Based on previous epidemiological studies, high fat and meat consumption may increase and fiber, calcium, and vegetable consumption may decrease the risk of colorectal cancer. We sought to address these hypotheses in a male Finnish cohort., Methods: We analyzed data from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC Study) where 27, 111 male smokers completed a validated dietary questionnaire at baseline. After an average of 8 years of follow-up, we documented 185 cases of colorectal cancer. The analyses were carried out using the Cox proportional hazards model., Results: The relative risk (RR) for men in the highest quartile of calcium intake compared with men in the lowest quartile was 0.6 (95% CI 0.4-0.9, p for trend 0.04). Likewise, the intake of milk protein and the consumption of milk products was inversely associated with risk of colorectal cancer. However, intake of dietary fiber was not associated with risk, nor was fat intake. Consumption of meat or different types of meat, and fried meat, fruits or vegetables were not associated with risk., Conclusions: In this cohort of men consuming a diet high in fat, meat, and fiber and low in vegetables, high calcium intake was associated with lowered risk of colorectal cancer.

The association between physical activity and prostate cancer was evaluated in the trial-based cohort of the Alpha-Tocopherol, Beta-Carotene (ATBC) Cancer Prevention Study (n = 29,133). During up to nine years of follow-up, 317 men developed incident prostate cancer. The relationship between occupational, leisure, and combined activity and prostate cancer was assessed in multivariate Cox regression models that adjusted for intervention group, benign prostatic hyperplasia, age, smoking, and urban residence. Compared with sedentary workers, relative risks (RR) and 95 percent confidence intervals (CI) for occupational walkers, walker/lifters, and heavy laborers were 0.6 (CI = 0.4-1.0), 0.8 (CI = 0.5-1.3), and 1.2 (CI = 0.7-2.0), respectively. Among working men, leisure activity (active cf sedentary) was associated inversely with risk (RR = 0.7, CI = 0.5-0.9). This inverse association for leisure activity was observed, with the exception of heavy laborers, for all occupational activity levels, and was strongest among walkers compared with men sedentary at work and leisure, and to a lesser degree among walker/lifters. These results are consistent with a protective effect of physical activity on prostate cancer.