Colonoscopy surveillance for high risk polyps does not always prevent colorectal cancer

Figure 2 Cumulative incidence of de novo cancers after polypectomy in 4610 patients (A). A: Observed cumulative incidence curves of patients who developed CRC at the same site (dashed lines) and a different site (dashed lines) from the index polyp in year 1, 2 and 3 were 0.3, 0.5, and 0.7 vs 0.17, 0.24, and 0.33, respectively. B: Survival after CRC diagnosis at the same and different site. Kaplan-Meier Curves for Overall Survival among patients who developed CRC at the same site and a different site distinct from the site of the high risk polyp indicates that there is no significant difference between the two groups. C: Cancer location, as compared to removed polyp location in patients who developed CRC in area distinct from polypectomy site of the high risk polyp. From left to right: right colon polyps, left colon polyps, rectal polyps. On Y axis is the number of right colon cancers (blue); left colon cancer (red) and rectal cancer (green).The figure shows that right sided colon cancer was the most frequent location for a cancer to develop in a site distinct from the index polyp regardless of the location for the index polyp.