Deborah M. Winn

A case-control study of oral and pharyngeal cancer conducted in four areas of the United States provided information on the tobacco and alcohol use of 1114 patients and 1268 population-based controls. Because of the large study size, it could be shown that the risks of these cancers among nondrinkers increased with amount smoked, and conversely that the risks among nonsmokers increased with the level of alcohol intake. Among consumers of both products, risks of oropharyngeal cancer tended to combine more in a multiplicative than additive fashion and were increased more than 35-fold among those who consumed two or more packs of cigarettes and more than four alcoholic drinks/day. Cigarette, cigar, and pipe smoking were separately implicated, although it was shown for the first time that risk was not as high among male lifelong filter cigarette smokers. Cessation of smoking was associated with a sharply reduced risk of this cancer, with no excess detected among those having quit for 10 or more years, suggesting that smoking affects primarily a late stage in the process of oropharyngeal carcinogenesis. The risks varied by type of alcoholic beverage, being higher among those consuming hard liquor or beer than wine. The relative risk patterns were generally similar among whites and blacks, and among males and females, and showed little difference when oral and pharyngeal cancers were analyzed separately. From calculations of attributable risk, we estimate that tobacco smoking and alcohol drinking combine to account for approximately three-fourths of all oral and pharyngeal cancers in the United States.

BACKGROUND: The magnitude of risk conferred by the interaction between tobacco and alcohol use on the risk of head and neck cancers is not clear because studies have used various methods to quantify the excess head and neck cancer burden. METHODS: We analyzed individual-level pooled data from 17 European and American case-control studies (11,221 cases and 16,168 controls) participating in the International Head and Neck Cancer Epidemiology consortium. We estimated the multiplicative interaction parameter (psi) and population attributable risks (PAR). RESULTS: A greater than multiplicative joint effect between ever tobacco and alcohol use was observed for head and neck cancer risk (psi = 2.15; 95% confidence interval, 1.53-3.04). The PAR for tobacco or alcohol was 72% (95% confidence interval, 61-79%) for head and neck cancer, of which 4% was due to alcohol alone, 33% was due to tobacco alone, and 35% was due to tobacco and alcohol combined. The total PAR differed by subsite (64% for oral cavity cancer, 72% for pharyngeal cancer, 89% for laryngeal cancer), by sex (74% for men, 57% for women), by age (33% for cases <45 years, 73% for cases >60 years), and by region (84% in Europe, 51% in North America, 83% in Latin America). CONCLUSIONS: Our results confirm that the joint effect between tobacco and alcohol use is greater than multiplicative on head and neck cancer risk. However, a substantial proportion of head and neck cancers cannot be attributed to tobacco or alcohol use, particularly for oral cavity cancer and for head and neck cancer among women and among young-onset cases.

A case-control study in North Carolina involving 255 women with oral and pharyngeal cancer and 502 controls revealed that the exceptionally high mortality from this cancer among white women in the South is primarily related to chronic use of snuff. The relative risk associated with snuff dipping among white nonsmokers was 4.2 (95 per cent confidence limits, 2.6 to 6.7), and among chronic users the risk approached 50-fold for cancers of the gum and buccal mucosa--tissues that come in direct contact with the tobacco powder. In the absence of snuff dipping, oral and pharyngeal cancer resulted mainly from the combined effects of cigarette smoking and alcohol consumption. The carcinogenic hazard of oral snuff is of special concern in view of the recent upswing in consumption of smokeless tobacco in the United States.

The Third National Health and Nutrition Examination Survey-Phase 1, conducted from 1988 to 1991 in the United States, included an assessment of dental caries in US children and adolescents and provided the opportunity for differences in dental caries status to be viewed by a ge, sex, race, and race-ethnicity. The measurement of dental caries in children and adolescents from 2-17 years of age included the number of decayed, missing, and filled permanent tooth surfaces and teeth, and the number of decayed, and filled primary tooth surfaces and teeth. Additionally, a brief visual inspection for the presence or absence of early childhood caries in the maxillary incisors was conducted for children 12-23 months of age. The survey yielded weighted estimates for 1988-1991 for over 58 million US children and adolescents 1 to 17 years of age. For infants aged 12-23 months, 0.8% were scored positive for early childhood caries. Over 60% (62.1%) of the children aged 2-9 years were caries-free in their primary dentition. Over half (54.7%) of the children 5-17 years were caries-free in their permanent dentition. The occurrence of caries in the permanent dentition is clustered: A quarter of the children and adolescents ages 5 to 17 with at least one permanent tooth accounted for about 80% of the caries experienced in permanent teeth. Differences in caries experience were found among race and race-ethnicity subpopulations, and caries patterns for the primary and permanent dentition were dissimilar. Further analyses are needed to explore other potential determinants of caries in children.