Oral and oropharyngeal cancer, aryl hydrocarbon hydroxylase inducibility and smoking. A follow-up study.

In a series of 50 consecutive cases with oral or oropharyngeal malignancies, aryl hydrocarbon hydroxylase (AHH) inducibility and smoking habits were studied. 82% of the patients were smokers. The AHH levels were divided into high, intermediate and low groups and were correlated to a healthy control material also divided into the groups mentioned. A significant overrepresentation of patients with a high AHH level (p less than 0.0005) as well as an underrepresentation of low AHH levels (p less than 0.01) was found. Smokers with a high AHH level run a sixfold risk of developing cancer in this area and develop it earlier in life than people with low or intermediate AHH levels. Recurrences or secondary malignancies in the upper digestive tract or airways were substantially higher in the high AHH level group as compared to the other. A high AHH inducibility level thus is of both pathogenetic as well as prognostic importance in oral and/or oropharyngeal cancer.