RESUMO
Objective:To investigate the incidences of metachronous advanced adenoma (MAA) in patients with simultaneous multiple primary colorectal cancer (CRC) and patients with sporadic CRC.Methods:From January 1, 2008 to September 30, 2022, at Beijing Shijitan Hospital, Capital Medical University, CRC patients who underwent surgery and 3 years follow-up with endoscopy were enrolled. The patients completed colonoscopy at least 2 times during follow-up in 6 to 36 months after surgery, and the interval between the 2 times colonoscopies was over 6 months. Clinical data including age, gender, and tumor location, stage, pathological features, combined underlying diseases, preoperative carcinoembryonic antigen, hemoglobin and other laboratory results, baseline colonoscopy results, and detection of MAA were collected. According to age (±2 years old), gender, location of primary lesion and stage of tumor, patients with simultaneous CRC or sporadic CRC were matched at 1∶1 ratio by propensity score matching. The cumulative risks of MAA in patients with simultaneous multiple primary CRC and patients with sporadic CRC were calculated. Cox proportional hazard regression was used to analyze the influencing factors in the occurrence of MAA.Results:A total of 814 CRC patients were enrolled and matched. After paired matching, there were 36 cases of simultaneous multiple primary CRC (78 lesions) and 78 cases of sporadic CRC (78 lesions). The cumulative incidences of MAA at 1, 2 and 3 years of simultaneous CRC group were 11.1%(4/36), 22.2%(8/36) and 33.3%(12/36), respectively. The cumulative incidences of MAA at 1-, 2- and 3-year of sporadic CRC group were 3.8%(3/78), 12.8%(10/78) and 20.5%(16/78), respectively.Simultaneous CRC was correlated with an increase in the 3-year cumulative incidence of MAA ( HR=4.163, 95% confidence interval(95% CI) 1.032 to 4.721, P=0.047). Especially in left-sided CRC, the risk of MAA in simultaneous CRC increased ( HR=7.186, 95% CI 1.602 to 20.787, P=0.010). The results of multivariate cox-regression analysis indicated that detection of simultaneous advanced adenoma at baseline endoscopy was an independent risk factor of MAA ( HR=3.175, 95% CI 1.411 to 7.142, P=0.005). Conclusion:Colouoscopy follow-up should be strengthened in patients with simultaneous multiple primary CRC and simultaneous advanced adenomas.