An analysis of esophageal cancer incidence in Cixian county from 1974 to 1996.
AIM: To describe the incidence of esophageal cancer (EC) in Cixian, a county of Hebei province during 1974-1996. We analyzed the sex and age characteristics as well as the geographic distribution of EC, in order to determine the impact so that methods of preventing and controlling EC in Cixian can be put in place. METHODS: Since the early 1970s, the cancer registry system has been established, which collects the cancer incidence in Cixian county. The malignant tumors were coded according to International Classification of Disease IX (ICD-9). All the data were checked and analyzed using EPIINFO. RESULTS: The trend of the incidence rate of EC from 1974 to 1996 had declined, (229.9/100 000 vs 178.5/100 000, Odds ratio=1.47, 95 % CI:1.32-1.63, chi(2)=52.89. trend chi(2)=26.54, P<0.001). The incidence rate of males declined significantly (281.81/100 000 vs 157.96/100 000, Odds ratio=1.61, 95 % CI: 1.41-1.84, chi(2)=47.85. Trend chi(2)=44.86, P<0.001), whereas, the females remained steady (157.96/100 000 vs 133.41/100 000, odds ratio=1.28, 95 % CI:1.17-1.49, chi(2)=9.26. trend chi(2)=2.69, P>0.05). Male average annual incidence rate was 142.80/100 000 and the female's was 95.18/100 000. The sex ratio (males to females) was 1.50:1. The incidence rate was increasing along with the age. As to the geographic distribution, the incidence rate in mountainous areas and hilly areas showed a significantly declining trend (mountainous areas, trend chi(2)=149.93, P<0.001; hilly areas, trend chi(2)=42.70, P<0.001). The incidence rate of EC in plain areas had increased (trend chi(2)=22.39, P<0.001). CONCLUSION: The incidence rate of EC in Cixian county shows a trend and has declined after two decades, especially in mountainous area. But compared to other regions in the world, Cixian county still had a high incidence rate of EC.