[Prospective evaluation on the impact of colonoscopy regarding the incidence of colorectal cancer]

Abstract

Objective: To evaluate the impact of colonoscopy on the incidence of colorectal cancer (CRC). Methods: This study was based on the Screening Project of Early Diagnosis and Treatment of CRC in Jiashan county, Zhejiang province. After excluding participants with incomplete information, these with individual history of CRC, those with CRC, enteritis or ulcer, noticed through colonoscopy exam at baseline, a total of 25 894 participants were finally included. Cox proportional hazards regression model was used to analyze the association between colonoscopy and the incidence of CRC. Results: This study was followed up for 160 113 person-years with a median of 5.67 years. During the follow-up period, 127 of them developed the CRC. The incidence rates of CRC in participants, were 202.35 per 100 000 person-years, 40.93 per 100 000 person-years and 63.62 per 100 000 person-years, respectively among the following three groups: who did not take the colonoscopy, without colorectal lesions or with benign colorectal lesions noticed by the colonoscopy and the differences were statistically significant (P<0.05). After adjusting for potential confounding factors, the HRs(95%CI) of CRC were 0.24 (0.16-0.36) and 0.29 (0.17-0.49), among those who did not have or had colorectal lesions in the participants who underwent the colonoscopy. Stratified by anatomic site, age and sex, results showed that the associations among the aforementioned groups were relatively stable. Conclusion: Colonoscopy could effectively contribute to the reduction of CRC incidence in the high-risk population.

Keywords: Cohort study; Colonoscopy; Colorectal neoplasm; Screening.