An examination of male and female odds ratios by BMI, cigarette smoking, and alcohol consumption for cancers of the oral cavity, pharynx, and larynx in pooled data from 15 case-control studies

Abstract

Background: Greater tobacco smoking and alcohol consumption and lower body mass index (BMI) increase odds ratios (OR) for oral cavity, oropharyngeal, hypopharyngeal, and laryngeal cancers; however, there are no comprehensive sex-specific comparisons of ORs for these factors.

Methods: We analyzed 2,441 oral cavity (925 women and 1,516 men), 2,297 oropharynx (564 women and 1,733 men), 508 hypopharynx (96 women and 412 men), and 1,740 larynx (237 women and 1,503 men) cases from the INHANCE consortium of 15 head and neck cancer case-control studies. Controls numbered from 7,604 to 13,829 subjects, depending on analysis. Analyses fitted linear-exponential excess ORs models.

Results: ORs were increased in underweight (< 18.5 BMI) relative to normal weight (18.5-24.9) and reduced in overweight and obese categories (≥ 25 BMI) for all sites and were homogeneous by sex. ORs by smoking and drinking in women compared with men were significantly greater for oropharyngeal cancer (p < 0.01 for both factors), suggestive for hypopharyngeal cancer (p = 0.05 and p = 0.06, respectively), but homogeneous for oral cavity (p = 0.56 and p = 0.64) and laryngeal (p = 0.18 and p = 0.72) cancers.

Conclusions: The extent that OR modifications of smoking and drinking by sex for oropharyngeal and, possibly, hypopharyngeal cancers represent true associations, or derive from unmeasured confounders or unobserved sex-related disease subtypes (e.g., human papillomavirus-positive oropharyngeal cancer) remains to be clarified.

Figure 1

Odds ratios for oral cavity, oropharyngeal, hypopharyngeal and laryngeal cancers by categories of body mass index (BMI) for males (solid symbol) and females (open symbol) and fitted restricted cubic splines, with knots at 25, 30 and 40 BMI at all sites, except hypopharynx, with knots at 20 and 30 BMI. Abscissa values for ORs were located at the category means, with fitted splines adjusted to the mean BMI for the referent category. Pooled data from the International Head and Neck Cancer Epidemiology (INHANCE) Consortium for never and ≤10 DPD drinkers.

Figure 2

Odds ratios for oral cavity, oropharyngeal, hypopharyngeal and laryngeal cancers by categories of pack-years and number of cigarettes smoked per day (CPD) for males (solid symbol) and females (open symbol), and a fitted model with linear odds ratios in pack-years. Bars represent 95% confidence interval. Pooled data from the International Head and Neck Cancer Epidemiology (INHANCE) Consortium for never and current cigarette-only smokers.

Figure 3

Estimated excess odds ratios per pack-year for males and females for oral cavity, oropharyngeal, hypopharyngeal and laryngeal cancers within categories of cigarettes per day (CPD) (square symbol) with 95% confidence interval, model (2) fitted to all data (solid line) and to never and 10+ CPD smokers (dash line). Pooled data from the International Head and Neck Cancer Epidemiology (INHANCE) Consortium for never and current cigarette-only smokers.

Figure 4

Odds ratios for oral cavity, oropharyngeal, hypopharyngeal and laryngeal cancers by categories of drink-years of alcohol consumption and number of drinks per day (DPD) for males (solid symbol) and females (open symbol), and a fitted model with linear odds ratios in drink-years. Bars represent 95% confidence interval. Pooled data from the International Head and Neck Cancer Epidemiology (INHANCE) Consortium for never and ≤10 DPD drinkers.

Figure 5

Estimated excess odds ratios per drink-year for males and females for oral cavity, oropharyngeal, hypopharyngeal and laryngeal cancers within categories of drinks per day (DPD) (square symbol) with 95% confidence interval, model (2) fitted to never and ≤10 DPD (solid line). Pooled data from the International Head and Neck Cancer Epidemiology (INHANCE) Consortium for never and ≤10 DPD drinkers.