Clinical and endoscopic characteristics of post-colonoscopy colorectal cancers detected within 10 years after a previous negative examination

Background and study aims We sometimes encounter colorectal cancer (CRC) that is discovered during the time interval between initial colonoscopy and the recommended follow-up examination. Although several studies reported such cases of CRC, most were based on registry data, which implied that the endoscopic quality was not consistent or guaranteed. We aimed to clarify these clinical and endoscopic characteristics at our high-volume center where a retrospective survey could be precisely performed. Patients and methods We retrospectively analyzed patients with CRC who underwent endoscopic resection or surgery from April 2002 to December 2010, categorizing them into two groups: a “study group” of patients with a negative colonoscopy during the previous 10 years, and a “control group” of patients without a previous colonoscopy or with a previous colonoscopy more than 10 years prior. Results A total of 2042 patients had CRC, among which 55 patients were classified into the study group and the remaining 1989 into the control group. The CRC cases in the study group showed a significant association with smaller (< 30 mm) tumor size (odds ratio [OR] 2.3; 95 % confidence interval [CI] 1.3–4.0) and proximal tumor site (OR 1.7; 95 %CI 0.9–2.9). In addition, right-sided and depressed-type T1 CRCs were significantly more common in the study group. Conclusions Tumor size and location were associated with CRCs detected within 10 years after the negative examination. In addition, depressed-type T1 CRCs were more common. Therefore, we should pay more attention to small, right-sided, or depressed-type tumors in daily colonoscopy.

Clinicopathological Characteristics and Endoscopic Features of Early Gastric Cancers Diagnosed After Helicobacter pylori Eradication

Background. Helicobacter pylori (H. pylori) infection is an important risk factor for developing gastric cancer. However, even after H. pylori eradication, early gastric cancer (EGC) can develop. We elucidated the characteristics of EGCs diagnosed after H. pylori eradication. Methods. Thirty-six EGCs in 32 patients diagnosed after H. pylori eradication were defined as the eradication group (H. pylori-EG). The clinicopathological and endoscopic features were compared with those of 156 EGCs in 140 patients in the H. pylori-positive group (H. pylori-PG). Twenty-nine EGC lesions in the H. pylori-EG were further divided into two subgroups: the first included six lesions of none to mild atrophic mucosa around the EGC, and the second included 23 lesions of moderate to severe atrophic mucosa around the EGC. We compared them between the two subgroups. Results. Endoscopic features of EGCs in the H. pylori-EG were characterized as small (P = 0.049) and of the depressed type (P = 0.022) compared with those in the H. pylori-PG. EGCs in the H. pylori-EG were detected on the upper region of the stomach more frequently than those in the H. pylori-PG (P = 0.002). As for submucosal ECGs in the H. pylori-EG, it was more likely to be seen in the none to mild atrophic mucosa subgroup compared to the moderate to severe atrophic gastric mucosa subgroup (P = 0.003). Conclusions. EGCs after H. pylori eradication were characterized as small and of the depressed type. Submucosal invasive EGCs developed more frequently in the none to mild atrophic mucosa after H. pylori eradication. Therefore, careful patient follow-up is important after H. pylori eradication.

Clinicopathological Characteristics and Endoscopic Features of Early Gastric Cancers Diagnosed After Helicobacter pylori Eradication: A Retrospective Study

Background: Helicobacter pylori (H. pylori) infection is an important risk factor for developing gastric cancer. However, even after H. pylori eradication, early gastric cancer (EGC) can develop. We elucidated the characteristics of EGCs diagnosed after H. pylori eradication. Methods: Thirty-six EGCs in 32 patients diagnosed after H. pylori eradication were defined as the eradication group (H. pylori-EG). The clinicopathological and endoscopic features were compared with those of 156 EGCs in 140 patients in the H. pylori-positive group (H. pylori-PG). Twenty-nine EGC lesions in the H. pylori-EG were further divided into two subgroups: the first included six lesions of no to mild atrophic mucosa around the EGC, and the second included 23 lesions of moderate to severe atrophic mucosa around the EGC. We compared them between the two subgroups. Results: Endoscopic features of EGCs in the H. pylori-EG were characterized as small (P = 0.049) and of the depressed type (P = 0.022) compared with those in the H. pylori-PG. EGCs in the H. pylori-EG were detected in the upper region of the stomach more frequently than those in the H. pylori-PG (P = 0.002). Submucosal ECGs in the H. pylori-EG were more likely to be seen in the no to mild atrophic mucosa subgroup (4/6, 67%) compared with the moderate to severe atrophic gastric mucosa subgroup (1/23, 4%) (P = 0.003). Conclusions: Careful follow-up endoscopies are necessary after H. pylori eradication.