Inflammation may be linked to the pathogenesis of colorectal cancer. However, two conflicting observational results were recently reported on the relationship between the inflammatory marker C-reactive protein (CRP) and the risk of colorectal cancer. Few epidemiologic studies have examined the association between inflammatory markers and the risk of colorectal cancer. We prospectively examined the mortality and incidence risk for colon and rectal cancers among 424,419 Koreans (108,907 men and 315,512 women). The subjects were 40 to 95 years of age and from the Korean Cancer Prevention Study (KCPS) cohort. All subjects received medical examination from the National Health Insurance Corporation in 1993 and 1995. The maximum follow-up period was 10 years, and the follow-up periods began in January 1, 1994 and ended in December 31, 2003. An elevated white blood cell count (WBC) was associated with a higher mortality risk of colon cancer (highest versus lowest quartile: men, 1.55, 95% CI 1.10-2.18, p for trend = 0.0014; women, 1.51, 95% CI 1.12- 2.03, p for trend = 0.0049). Similarly, an elevated WBC was associated with a higher incidence risk of colon cancer (highest versus lowest quartile: men, 1.38, 1.09-1.76, p for trend = 0.0017; women, 1.46, 95% CI 1.20-1.78, p for trend= 0.0003). A positive linear trend was also observed in non- smokers. There was no significant association between WBC and the risk of rectal cancer. Our findings demonstrate that an elevated WBC is associated with an increase in both the mortality and incidence rates of colon cancer. These results support our hypothesis that inflammation increases the risk of colon cancer.
Smoking ; Risk Factors ; Rectal Neoplasms/epidemiology/mortality ; Prospective Studies ; Middle Aged ; Male ; *Leukocyte Count ; Humans ; Follow-Up Studies ; Female ; Colorectal Neoplasms/epidemiology/mortality ; Colonic Neoplasms/*epidemiology/mortality ; Cohort Studies ; Biological Markers ; Aged, 80 and over ; Aged ; Adult

OBJECTIVETo investigate the incidence and mortality of colorectal cancer in China from 1998 to 2002, and to analyze its prevalence trend.

METHODSThe cancer registration data in 10 cities and counties in China during the period of 1988-1992, 1993-1997 and 1998-2002 were used to investigate the incidence, mortality, and prevalence trend of colorectal cancer from 1988 to 2002.

RESULTSThe total number of new cases of colorectal cancer in the 10 cities and counties during 1988-2002 was 62,793, accounting for 9.27% of all malignant tumors. The crude incidence rate was 20.10/10(5), and the age-standardized incidence adjusted by world population was 15.63/10(5). The total number of death of colorectal cancer in the 10 cities and counties during 1988-2002 was 35,545, accounting for 7.37% of all malignant tumors. The mortality rate was 11.38/10(5), the age-standardized mortality rate adjusted by world population was 8.70/10(5). The incidence and mortality of colorectal cancer during 1988-2002 increased by 38.56% and 15.30%, respectively, and the incidence and mortality rates in urban area was higher than that in rural area, and higher in males than in females. The crude incidence rate of colon cancer was higher than that of rectal cancer, especially in urban area, but the mortality of rectal cancer was a little bit higher than that of colon cancer.

CONCLUSIONThere is an increasing trend in both the incidence and mortality rates of colorectal cancer from 1988-2002 in the 10 cities and counties in China. Measures should further be taken in the prevention and treatment of colorectal cancer in the whole population of China in future.

Adolescent ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; China ; epidemiology ; Cities ; Colonic Neoplasms ; epidemiology ; mortality ; Colorectal Neoplasms ; epidemiology ; mortality ; Female ; Humans ; Incidence ; Infant ; Male ; Middle Aged ; Rectal Neoplasms ; epidemiology ; mortality ; Rural Population ; Sex Factors ; Urban Population ; Young Adult