OBJECTIVEBased on the data from National Cancer Registry between 1998 and 2007, to analyze the colorectal cancer incidence trend in China, and further to predict its incidence between 2008 and 2015.

METHODSWe picked up the incidence data of 111 281 cases of colorectal cancer in total from National Central Cancer Registry Database between 1998 and 2007, covering 446 734 668 person-year. The annual incidence rate of colorectal cancer both by area and gender were calculated; while the age standardized rate (ASR) was standardized by world's population age structure. The incidence trend was analyzed and the annual percentage change (APC) was calculated by JoinPoint software. Age-Period-Cohort Bayesian Model was applied to fit the colorectal cancer incidence trend in China between 1998 and 2007; and further to predict its incidence between 2008 and 2015.

RESULTSFrom 1998 to 2007, the colorectal cancer registered incidence was 24.91/100 000 (111 281/446 734 668), with the ASR at 17.67/100 000. The incidence in male population was 26.50/100 000 (60 015/226 508 545), with ASR at 19.90/100 000; and the incidence in female was 23.28/100 000 (51 266/220 226 123), with ASR at 15.73/100 000. In urban area, the male incidence rose from 23.29/100 000 (2617/11 237 967) in 1998 to 37.84/100 000 (8534/22 551 353) in 2007; while the female incidence increased from 21.75/100 000 (2357/10 838 355) to 31.34/100 000 (6913/22 057 787). And in rural areas, the male and female incidences rose from 10.36/100 000 (448/4 323 628) and 8.86/100 000 (372/4 197 806) in 1998 to 16.80/100 000 (1290/7 677 484) and 13.00/100 000 (978/7 522 690) in 2007 respectively. In this decade, the colorectal cancer incidence has increased both in urban and rural areas. In urban area, the male APC value was 5.5% and the female APC value was 4.0%; while in rural area, the male and female APC values were 6.0% and 4.3% respectively. After adjusted by age structure, the uptrend became gently; with the urban male and urban female APC values separately increased by 3.7%, 2.5% and 2.3%. The rural male APC value rocketed up by 8.4% after its inflection point in 2004. The Bayesian model predicted that the male and female colorectal cancer incidences would separately reach 33.92/100 000 (125 thousand cases) and 27.13/100 000 (93 thousand cases) in urban areas; and 13.61/100 000 (48 thousand cases) and 13.68/100 000 (45 thousand cases) in rural areas by year 2015.

CONCLUSIONThe colorectal cancer incidence in China has been increasing annually; and it will continue to rise in the next years.