Int. zyxwvutsrqp J. Cancer: zyxwvutsr 36, 153-158 (1985) zyxwvut @ 1985 zyxwvutsrq Alan R. Liss, Inc. SURVEY OF A POPULATION WITH A HIGH INCIDENCE OF ORAL AND OESOPHAGEAL CANCER David G. ZARIDZE”~, Maria BLETTNER’, Nikolai N. TRAPEZNIKOV~, Juri P. KUVSHINOV~, Eugene G. MATIAKIN~, Boris P. POLJAKOV~, Boris K. PODDUBNI~, Svetlana M. PARSHIKOVA~, Vera I. ROTTEN BERG^, Farchad s. CHAMRAKULOV3, Mamlakat c. CHODJAEVA~, Hans F. STICH~, Miriam P. Rosr~~, David I. THuRNHAM5, Dietrich HOFFMANN6 and Klaus D. B R U N N E M A N N ~ ‘International Agency for Research on Cancer, 150 cours Albert-Thomas, 69372 Lyon Cedex zyx 08, France; 2All Union Cancer Research Centre of the USSR Academy of Medical Sciences, 6 Kashirskoye Chaussee, 115478 Moscow; 3Samarkand Medical Institute, 703000 Samarkand, USSR; 4Environmental Carcinogenesis Unit, British Columbia Cancer Research Centre, 601 West loth Avenue, Vancouver,B. C., V5Z IL3 Canada; ’Clinical Investigation Unit, Dudley Road Hospital, Dudley Road, Birmingham B18, 7QH, UK; and 6Naylor Dana Institute for Disease Prevention, American Health Foundation, Dana Road, Valhalla, NY 10595, USA. The results of a survey of a population with a high incidence of oral and oesophageal cancer are pre- sented. The population under study appears to have several epidemiologic characteristics, some of which may be associated with a high incidence of oral and oesophageal cancer. A remarkably high proportion (41%) of the men surveyed were nass users and this habit, like the use of other types of tobacco mixtures, has been related to oral cancer. Oral leukoplakia and chronic oesophagitis (conditions thought t o be precur- sors of oral and oesophageal cancer) have been diag- nosed in 11% and zyxwvuts 60%. respectively, of the persons examined. Analysis of the relationship between nass use. cigarette smoking, oral leukoplakia and oeso- phagitis revealed that the prevalence of oral leuko- plakia is highest among cigarette smokers who use nass. It appears that nass use does not affect the fre- quency of occurrence of chronic oesophagitis. How- ever, a slight elevation of the prevalence odds ratio was observed for current smokers and drinkers. Bio- chemical analysis of the blood of a random sample of the surveyed population revealed low levels of ribo- flavin, vitamin A and carotenoids-vitamins that most probably have a protective effect against the develop- ment of cancer. The mutagenicity test has shown that nass contains a chemical or chemicals that exert a genotoxic effect. Chemical analysis revealed the pres- ence in nass of tobacco-specific N-nitroso compounds. The high incidence of oral cancer in the Central Asian republics of the Soviet Union is attributed to the use of nass, viz., a mixture of tobacco, ash, cotton oil and lime (Paches and Milievskaya, 1980). The most frequent site of oral cancer is the place in the mouth where nass is usually kept. For example, in the Uzbek, Tadzhik and Turkmenian Republics, where nass is usually placed under the tongue, the most frequent site of oral cancer is the floor of the mouth and the lower surface of the tongue, while in Kazakhstan, where nass is placed between the lower lip and the gum, the gum, lower lip and anterior tongue were found to be the sites chiefly affected (Paches and Milievskaya, 1980). The causes of the increased incidence of oesopha- geal cancer in Soviet Central Asia are still unknown, although a possible role of vitamin deficiency has been implicated (Kolicheva, 1980). Studies in Northern Iran and Northern China have indicatedvthat high incidence of oesophageal cancer is associated with riboflavin and vitamin A deficiencies, drinking hot tea and the use of opium (Cook-Mozaffari et al., 1979; Day and Munoz, 1982; Thurnham et al., 1982). Other studies have implicated the role of cigarette smoking and alcohol consumption in the aetiology of cancer of the oesopha- gus (Day and Munoz, 1982). Oral and oesophageal cancer have been associated with the presence of oral leukoplakia and chronic oes- ophagitis, respectively. An increase in the prevalence of oral leukoplakia was observed in persons who used different types of tobacco mixtures and betel (Hira- yama, 1966; Mehta et al., 1971; Pindborg, 1980). It has been suggested that chronic oesophagitis is a pre- cursor of oesophageal cancer. Kolicheva (1970) and Kolicheva et al. (1970) reported high prevalences (88 % and 66%) of chronic oesophagitis in 2 areas with a high incidence of oesophageal cancer in Kazakhstan in a series of autopsies of people who had died from causes other than oesophageal cancer, and described the endoscopic and histological picture of this condi- tion. Chronic oesophagitis was discovered in 85 % and 66% of the population in North Iran and North China, respectively, during an endoscopic survey in areas with a high incidence of oesophageal cancer (Crespi et al., 1979; Munoz et al., 1982). The test for the frequency of micronucleus formation has been applied to persons who chew betel quid or other types of smokeless tobacco. It has been shown that the frequency of micronucleus formation is ele- vated in persons who chew betel or other types of quid, compared with non-chewers (Stich et al., 1982a,b). The micronuclei, which are detectable in exfoliated mucosal cells, are formed from chromo- some fragments and aberrant chromosomes not in- cluded during their mitotic cycle in the main nucleus. Chemical and bioassay data as well as the results of saliva analysis strongly indicate that nicotine-derived and tobacco-specific N-nitrosamines contribute signif- icantly to the increased risk of oral cancer in tobacco chewers and snuff dippers. These nitrosamines are highly carcinogenic; they are not only present in the tobacco but are most likely also formed in the oral cavity during tobacco chewing and snuff dipping (Hoffmann and Hecht, 1985). MATERIAL AND METHODS The survey was performed in Samarkand Oblast of Uzbek SSR in an area where the age-standardized 7T0 whom reprint requests should zyx be sent. Received: January 28, 1985 and in revised form March 26, 1985.