Post-colonoscopy colorectal cancer: Characteristics and predictive factors.

INTRODUCTION AND AIMS: A high quality colonoscopy is key in preventing colorectal cancer, but the risk of colorectal cancer (CRC) exists. The aims of the study were to investigate the incidence, characteristics and predictive factors of post-colonoscopy colorectal cancer (PCCRC).

MATERIAL AND METHOD: A retrospective and prospective observational study was designed. A population undergoing colonoscopy between 1-01-1997 and 31-12-2014 was included. We analysed demographic variables, characteristics of the diagnostic colonoscopy of CRC, of the previous ones and the lesions found in them. To compare the PCCRC group versus the CRC group without previous colonoscopy, the Student's t-test and multiple logistic regression were used to determine predictive factors of PCCRC (SPSS® 15). The statistical significance was P<.05.

RESULTS: A total of 56,984 colonoscopies, 1,977 CRC and 132 patients (mean 70.8 years old, 56.8% male) with at least one colonoscopy in 10 years before were registered (PCCRC). Seventy and a half percent of the previous colonoscopies were completed and 63.7% had an adequate bowel preparation. Predictive factors of PCCRC were personal history of polyps (OR 35.01; 95% CI 11.1-110.8; P<.001), previous CRC (OR 176.64; 95% CI 51.5-606.1); P<.001), family history of CRC (OR 3.14; 95% CI 1.5-6.4); P=.002) and proximal CRC (OR 3.15; 95% CI 2.1-4.9; P<.001).

CONCLUSIONS: PCCRC rate in 10 years was 6.7%. An adequate follow-up and a high-quality colonoscopy could prevent PCCRC, especially in patients with risk factors.