POST-COLONOSCOPY COLORECTAL CANCER: INCIDENCE, CHARACTERISTICS AND PREDICTIVE FACTORS

Aims Post-colonoscopy CRC (PCCRC) has become an important quality indicator. Our aim was to determine its rate, characteristics, and associated factors.

Methods Multicenter, observational, retrospective study between 2015 and 2018 in 8 centers in the region of Alicante. We considered as PCCRC those developing up to 10 years after colonoscopy. The causes of PCCRC were categorized according to the World Endoscopy Organization (WEO) algorithm.

Results PCCRC was detected in 107 patients (mean age 72 years, 66% male), out of 101,524 colonoscopies (0.11%) and 2,508 CRC (4.27%), which resulted in a 1-year PC-CRC rate of 1.25%, 3-year rate 2.79%, 5-year rate 3.24%, 10-year rate of 4.01%. The PCCRCs were in right (42.4%), left (41.4%) and transverse (16.4%) colon with a mean size of 36mm, with 31.5% with stage I, 24.7% stage II, 32.6% stage III, 11.2% stage IV. According to WEO, 22.8% of PCCRCs were classified as incomplete resection, 7.9% as unresected detected lesions, 44.6% as missed lesions with adequate colonoscopy, and 24.8% as missed lesions with inadequate colonoscopy. Mean time between PCCRC diagnosis and previous colonoscopy was 42 months. Inadequate colonic cleansing and previous fragmented polypectomy were associated with the occurrence of PCCRC in the multivariate analysis (p<0.005).

Conclusions In our population, 4.27% of the diagnosed CRCs were PCCRC and, therefore, potentially preventable. Most of these lesions were in advanced stages and almost half were attributable to lesions not visualized despite adequate colonic cleansing. Inadequate colonic cleansing and previous fragmented polypectomy were independently associated with the occurrence of PCCRC.

Publication History

Article published online:
14 April 2022