Estimation of premature mortality from oral cancer in Japan, 1995 and 2005.

BACKGROUND

To better understand the picture of premature death from oral cancer, we estimated years of life lost (YLL) and average years of life lost (AYLL) of this cancer for the years 1995 and 2005 in Japan.

METHODS

We obtained the mortality data for 5-year age groups from the Vital Statistics of Japan for the years 1995 and 2005, an interval of 10 years. Age-standardized rates (ASRs) per 100,000 persons were calculated for each subset of oral cancer. We estimated YLL and AYLL according to life tables in Japan to reflect premature mortality.

RESULTS

For both men and women combined, 4099 and 5679 deaths due to oral cancer were recorded for the years 1995 and 2005. In men, cancer of tongue, oropharynx, and hypopharynx were the most frequently observed anatomic sites. We observed a total of 51,339.1 years of life lost in 1995 and 68,630.4 years in 2005, corresponding to an overall AYLL for all oral cancer deaths combined of 17.2 and 16.5 years earlier than life expectancy, respectively. The greatest AYLL was seen for deaths from nasopharyngeal cancer, with AYLL of 21.1 years in 1995 and 20.3 years in 2005. In women, cancer of the tongue and gum were the most affected anatomic sites. Total numbers of YLL were 18,884.8 years in 1995 and 24,765.7 in 2005, corresponding to an overall AYLL of 16.9 and 16.2 years earlier than life expectancy. The greatest AYLL was seen for deaths from nasopharyngeal cancer, with AYLL of 22.4 years and 20.4 years in 1995 and 2005, respectively.

CONCLUSION

The present study shows that cancer of pharynx, tongue, and gum were the most frequent oral cancers in both sexes in both 1995 and 2005, and responsible for a remarkable number of years of life expectancy lost. Deaths due to those cancer sites occurred about 16-21 years earlier than expected in men, and 14-22 years in women.