Geographical Variation of Liver Cancer Mortality in Korea (1992-1998)

The death rate of liver cancer in Korea has been reported as one of the highest in the world. This study was conducted to investigate geographical variations of liver cancer mortality in Korea in order to obtain insight into possible environmental factors related to liver cancer.

The sex-specific standardized mortality ratios (SMRs) of liver cancer were calculated for 168 basic administrative units in Korea based upon the vital statistics for the seven years 1992 to 1998, as well as the sex- and age-specific population of each area for 1995. The SMRs were classified into six categories and depicted on a map for each sex.

The southern provinces showed clearly higher mortality rates as compared to the rest of the country in both males and females. Looking at the maps in detail, there was a geographical variation even within the southern provinces. The areas around large rivers, some costal areas, and costal islands showed a high mortality rate. Even in the middle and northern provinces, the eastern costal areas showed relatively higher mortality rates as compared to inland areas. Conversely, some southern areas known for low levels of pollution showed relatively lower mortality rates.

This finding suggests a possible relationship between liver cancer and water-related foods from polluted rivers or seas. Further studies should be performed in order to clarify which factors cause this geographical variation.