Time trends in the mortality rates for tobacco- and alcohol-related cancers within the oral cavity and pharynx in Japan, 1950-94.

Mortality data of oral cancer over 40 years in Japan were analyzed to investigate time trends of the disease site-specifically and discuss the relation between these trends and the changing patterns of consumption of tobacco and alcohol beverages. Mortality rates were adjusted to the world standard population. In the males, overall oral cancer (ICD-9: 141-149) mortality rates have increased consistently from the lowest value of 1.25 (per 100,000 per year) in 1956 to 2.40 in 1992. The rates for females were constantly lower than those for males, and formed a modest peak of 0.96 in 1979. Regarding site-specific mortality rates, tongue cancer (141) presented a decreasing trend, while oro/hypopharyngeal (146, 148) and mouth (143-145) cancers showed increasing patterns, particularly in males. When the changing patterns of male truncated rates for ages 35-64 were compared with those of the annual consumption of cigarette and alcohol per capita, the time trend of oro/hypopharyngeal cancer mortality was analogous to cigarette consumption rather than to alcohol consumption, mouth cancer vice versa, and tongue cancer was not related to tobacco or alcohol consumption. The present findings suggest that tobacco and alcohol have different site-specific effects on the development of cancers within the oral cavity and pharynx.