Arylhydrocarbonhydroxylase inducibility and smoking habits in patients with laryngeal carcinomas

There is considerable evidence that the inducible enzyme aryl hydrocarbon hydroxylase (AHH) plays an important role in the activation of polycyclic aromatic hydrocarbons (PAH) to ultimate carcinogens. In man, a genetic heterogeneity of AHH inducibility has been demonstrated, and correlated to susceptibility to bronchogenic carcinomas following exposure to PAH. We assessed AHH inducibility in a control group of 102 healthy Swedish citizens and in 41 patients with laryngeal carcinomas. Frequencies of the three phenotypes of high, intermediate and low AHH inducibility in our control group; 8.8%, 42.2% and 49%, respectively, did not differ significantly from frequencies found in a white US population. In the laryngeal carcinoma group, there was a statistically highly significant overrepresentation of patients with high AHH inducibility, 36.6%, whereas 43.9% had an intermediate and 19.5% a low level. Most of the patients were heavy smokers. These findings add further support to the concept that susceptibility to PAH-induced carcinomas is associated with high levels of inducible AHH activity.