Objective: To evaluate the secular trend of liver cancer incidence 1973-2002 in Qidong, a high-prevalent area in Jiangsu province.
Methods: The population-based cancer registration data collected during the period of 1973-2002 were used to calculate the crude rate (CR), world age-standardized rate (WASR), five-year age-specific rate, truncated rate of those aged 35-64, cumulative rates of those aged 0-64 and 0-74, percent change (PC), and annual percent change (APC). The incidence rates by age, period/age, and cohort/age were analyzed and compared.
Results: The CR was 59.28 per 100,000 on average; and was 91.65 per 100,000 for males and 27.64 per 100,000 for females, with a sex ratio of 3.32:1. The WASR was 58.71 per 100,000 on average; and was 93.32 per 100,000 for males and 26.46 per 100,000 for the females. The truncated rate and cumulative rate of those aged 0-64 and 0-74 were 143.61 per 100,000 and 4.74% and 6.07% respectively. The PC and the APC were +30.90% and +1.58% for the crude incidence rate, and +12.33% and +0.41% for the age-standardized rate. The incidence data demonstrated a rising trend in general and a decreasing pattern for the age-specific rates under age of 35 by comparing the two 15-year periods. Decline trend also existed for the younger age groups when the time was divided into 6 subperiods. Birth cohort analysis showed notable reducing changes for those born after the year 1963.
Conclusion: The crude rate of incidence of liver cancer has arisen in general in the past 30 years in Qidong area, which may reflects the increase of middle-aged and elderly populations. Many years' comprehensive prevention measures taken in the area, however, have been and will continue to be effective on the decrease of the incidence of liver cancer among the younger generations.