Longitudinal Trends of Stomach Cancer and Esophageal Cancer in Yangzhong County: a High-incidence Rural Area of China

Objective: This study aims to investigate the recent trends in incidence rates of stomach cancer and esophageal cancer in a high-incidence rural area of China.

Methods: All new cancer occurrences registered between 1991 and 2003 in the Yangzhong Cancer Registry were reviewed. Yearly age-specific and age-adjusted incidence rates were calculated for males and for females. Longitudinal trends of cancer incidence were estimated by the estimated annual percentage change method.

Results: In total 12 691 incident cancer cases were registered, with 7159 males (56.41%) and 5532 females (43.59%). Adjusting to the world standard population, the incidence rate of all cancers decreased significantly across the period 1991-2003 from 357.02 to 283.21 per 10 person-years. For males this rate decreased from 447.22 to 346.72 per 10 person-years, and for females the incidence rate decreased from 284.36 to 225.73 per 10 person-years. The major cancers in Yangzhong County were stomach cancer and esophageal cancer, accounting for more than 70% of all cancer occurrences. During the past 13 years, the incidence rates of stomach cancer decreased greatly from 231.92 to 145.26 per 10 person-years in males and from 114.16 to 74.59 per 10 person-years in females. The estimated annual percentage changes of stomach cancer incidence were -2.96% [95% confidence interval (CI), -2.99% to -2.92%] in males and -2.86% (95% CI, -2.89% to -2.82%) in females. Incidence rates for esophageal cancer decreased slightly from 121.48 to 93.84 per 10 person-years in males with an estimated annual percentage change of -1.39% (95% CI, -1.42% to -1.36%), and from 99.74 to 73.73 per 10 person-years in females at an annual change of -2.18% (95% CI, -2.22% to -2.14%).

Conclusion: Findings from this study showed that, although there is a decreasing trend of stomach cancer and esophageal cancer in this high-incidence area, the rates remain high. Future effort should be directed toward identifying factors behind the high rates and those contributing to the decreasing trend.