A proxy approach to the determination of total caloric intake for use in cancer epidemiology

Higher micronutrient intake is associated with human papillomavirus-positive head and neck cancer: a case-only analysis

No studies have investigated dietary differences between head and neck squamous cell carcinoma (HNSCC) patients with human papillomavirus (HPV)-positive tumors and patients with HPV-negative tumors. This study was designed to investigate the relationship between diet and HPV status in HNSCC patients. Cases of HNSCC were recruited from 2 clinical centers participating in the University of Michigan Head and Neck Specialized Program of Research Excellence (SPORE). HPV tissue genotyping was performed, and epidemiological and dietary data collected. Multivariable logistic regression tested whether pretreatment consumption of 12 selected micronutrients was significantly associated with HPV-positive status in 143 patients newly diagnosed with cancer of the oral cavity or pharynx. After controlling for age, sex, body mass index, tumor site, cancer stage, problem drinking, smoking, and energy intake, significant and positive associations were observed between vitamin A, vitamin E, iron, β-carotene, and folate intake and HPV-positive status (P(trend) < 0.05), suggesting that diet may be a factor in the improved prognosis documented in those with HPV-positive HNSCC. Dietary differences by HPV status should be considered in prognostic studies to better understand the influence of diet on HNSCC survival.

Differences between estimated caloric requirements and self-reported caloric intake in the women's health initiative

PURPOSE

To compare energy intake derived from a food frequency questionnaire (FFQ) with estimated energy expenditure in postmenopausal women participating in a large clinical study.

METHODS

A total of 161,856 women aged 50 to 79 years enrolled in the Women's Health Initiative (WHI) Observational Study (OS) or Clinical Trial (CT) [including the Diet Modification (DM) component] completed the WHI FFQ, from which energy intake (FFQEI) was derived. Population-adjusted total energy expenditure (PATEE) was calculated according to the Harris-Benedict equation weighted by caloric intakes derived from the National Health and Nutrition Examination Survey. Stepwise regression was used to examine the influence of independent variables (e.g., demographic, anthropometric) on FFQEI-PATEE. Race, region, and education were forced into the model; other variables were retained if they increased model explanatory ability by more than 1%.

RESULTS

On average, FFQEI was approximately 25% lower than PATEE. Regression results (intercept=-799 kcal/d) indicated that body mass index (b=-23 kcal/day/kg.m(-2)); age (b=15 kcal/day/year of age); and study arm (relative to women in the OS, for DM women b=169 kcal/d, indicating better agreement with PATEE) increased model partial R(2)>.01. Results for CT women not eligible for DM were similar to those of women in the OS (b=14 kcal/d). There also were apparent differences by race (b=-152 kcal/d in Blacks) and education (b=-67 kcal/d in women with<high school).

CONCLUSION

This large, carefully studied population confirms previous observations regarding underestimates in self-reported caloric intake relative to estimates of metabolic need in younger women, and those with higher weight, with less education, and in Blacks. These differences, along with effects related to intervention assignment, underline the need for additional research to enhance understanding of errors in dietary measurement.

The effect of dietary exposures on recurrence and mortality in early stage breast cancer

We studied the effect of diet and body weight on recurrence and death in 472 women diagnosed with early-stage breast cancer in 1982-1984. From Cox proportional hazards regression models we found that the strongest effects were observed in premenopausal women. For example, after accounting for disease stage and age, reported baseline consumption (times/day) of butter, margarine, and lard (risk ratio (RR)=1.67; 95% confidence interval (CI)=1.17-2.39) and beer (drinks/day) (RR=1.58; 95% CI=1.15-2.17) increased the risk of recurrence. There also appeared to be an increased risk associated with consumption of red meat, liver, and bacon, corresponding to about a doubling of risk for each time per day that foods in this category were consumed (RR=1.93; 95 % CI=0.89-4.15). Relative body weight increased risk at the rate of 9% (RR=1.09; 95% CI=1.02-1.17) for each kg/m2 (equivalent to about 5.8 pounds for a woman 5'4" tall). For death, the results were similar, but relative weight was more strongly associated, increasing risk by 12% per kg/m2 (RR=1.12; 95% CI=1.03-1.22).