Nutrient-based dietary patterns and the risk of head and neck cancer: a pooled analysis in the International Head and Neck Cancer Epidemiology consortium

BACKGROUND

The association between dietary patterns and head and neck cancer has rarely been addressed.

PATIENTS AND METHODS

We used individual-level pooled data from five case-control studies (2452 cases and 5013 controls) participating in the International Head and Neck Cancer Epidemiology consortium. A posteriori dietary patterns were identified through a principal component factor analysis carried out on 24 nutrients derived from study-specific food-frequency questionnaires. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using unconditional logistic regression models on quintiles of factor scores.

RESULTS

We identified three major dietary patterns named 'animal products and cereals', 'antioxidant vitamins and fiber', and 'fats'. The 'antioxidant vitamins and fiber' pattern was inversely related to oral and pharyngeal cancer (OR=0.57, 95% CI 0.43-0.76 for the highest versus the lowest score quintile). The 'animal products and cereals' pattern was positively associated with laryngeal cancer (OR=1.54, 95% CI 1.12-2.11), whereas the 'fats' pattern was inversely associated with oral and pharyngeal cancer (OR=0.78, 95% CI 0.63-0.97) and positively associated with laryngeal cancer (OR=1.69, 95% CI 1.22-2.34).

CONCLUSIONS

These findings suggest that diets rich in animal products, cereals, and fats are positively related to laryngeal cancer, and those rich in fruit and vegetables inversely related to oral and pharyngeal cancer.

Association of marijuana smoking with oropharyngeal and oral tongue cancers: pooled analysis from the INHANCE consortium

BACKGROUND

The incidence of oropharyngeal and oral tongue cancers has increased over the last 20 years which parallels increased use of marijuana among individuals born after 1950.

METHODS

A pooled analysis was conducted comprising individual-level data from nine case-control studies from the United States and Latin America in the INHANCE consortium. Self-reported information on marijuana smoking, demographic, and behavioral factors was obtained from 1,921 oropharyngeal cases, 356 oral tongue cases, and 7,639 controls.

RESULTS

Compared with never marijuana smokers, ever marijuana smokers had an elevated risk of oropharyngeal [adjusted OR (aOR), 1.24; 95% confidence interval (CI): 1.06-1.47] and a reduced risk of oral tongue cancer (aOR, 0.47; 95% CI, 0.29, 0.75). The risk of oropharyngeal cancer remained elevated among never tobacco and alcohol users. The risk of oral tongue cancer was reduced among never users of tobacco and alcohol. Sensitivity analysis adjusting for potential confounding by HPV exposure attenuated the association of marijuana use with oropharyngeal cancer (aOR, 0.99; 95% CI, 0.71-1.25), but had no effect on the oral tongue cancer association.

CONCLUSIONS

These results suggest that the association of marijuana use with head and neck carcinoma may differ by tumor site.

IMPACT

The associations of marijuana use with oropharyngeal and oral tongue cancer are consistent with both possible pro- and anticarcinogenic effects of cannabinoids. Additional work is needed to rule out various sources of bias, including residual confounding by HPV infection and misclassification of marijuana exposure.

History of diabetes and risk of head and neck cancer: a pooled analysis from the international head and neck cancer epidemiology consortium

BACKGROUND

A history of diabetes is associated with an increased risk of several types of cancers. Whether diabetes is a risk factor for head and neck cancer (HNC) has received little attention.

METHODS

We pooled data from 12 case-control studies including 6,448 cases and 13,747 controls, and estimated OR and 95% CI for the associations between diabetes and HNC, adjusted for age, education level, sex, race/ethnicity, study center, cigarette smoking, alcohol use, and body mass index.

RESULTS

We observed a weak association between diabetes and the incidence of HNC overall (OR, 1.09; 95% CI: 0.95-1.24). However, we observed a modest association among never smokers (OR, 1.59; 95% CI: 1.22-2.07), and no association among ever smokers (OR, 0.96; 95% CI: 0.83-1.11); likelihood ratio test for interaction P = 0.001.

CONCLUSION

A history of diabetes was weakly associated with HNC overall, but we observed evidence of effect modification by smoking status, with a positive association among those who never smoked cigarettes.

IMPACT

This study suggests that glucose metabolism abnormalities may be a HNC risk factor in subgroups of the population. Prospective studies incorporating biomarkers are needed to improve our understanding of the relationship between diabetes and HNC risk, possibly providing new strategies in the prevention of HNC.

Vitamin E intake from natural sources and head and neck cancer risk: a pooled analysis in the International Head and Neck Cancer Epidemiology consortium

BACKGROUND

Evidence for the possible effect of vitamin E on head and neck cancers (HNCs) is limited.

METHODS

We used individual-level pooled data from 10 case-control studies (5959 cases and 12 248 controls) participating in the International Head and Neck Cancer Epidemiology (INHANCE) consortium to assess the association between vitamin E intake from natural sources and cancer of the oral cavity/pharynx and larynx. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression models applied to quintile categories of non-alcohol energy-adjusted vitamin E intake.

RESULTS

Intake of vitamin E was inversely related to oral/pharyngeal cancer (OR for the fifth vs the first quintile category=0.59, 95% CI: 0.49-0.71; P for trend <0.001) and to laryngeal cancer (OR=0.67, 95% CI: 0.54-0.83, P for trend <0.001). There was, however, appreciable heterogeneity of the estimated effect across studies for oral/pharyngeal cancer. Inverse associations were generally observed for the anatomical subsites of oral and pharyngeal cancer and within covariate strata for both sites.

CONCLUSION

Our findings suggest that greater vitamin E intake from foods may lower HNC risk, although we were not able to explain the heterogeneity observed across studies or rule out certain sources of bias.