Randomised comparison of postpolypectomy surveillance intervals following a two-round baseline colonoscopy: the Japan Polyp Study Workgroup

Abstract

ObjectiveTo assess whether follow-up colonoscopy after polypectomy at 3 years only, or at 1 and 3 years would effectively detect advanced neoplasia (AN), including nonpolypoid colorectal neoplasms (NP-CRNs).DesignA prospective multicentre randomised controlled trial was conducted in 11 Japanese institutions. The enrolled participants underwent a two-round baseline colonoscopy (interval: 1 year) to remove all neoplastic lesions. Subsequently, they were randomly assigned to undergo follow-up colonoscopy at 1 and 3 years (2-examination group) or at 3 years only (1-examination group). The incidence of AN, defined as lesions with low-grade dysplasia ≥10 mm, high-grade dysplasia or invasive cancer, at follow-up colonoscopy was evaluated.ResultsA total of 3926 patients were enrolled in this study. The mean age was 57.3 (range: 40–69) years, and 2440 (62%) were male. Of these, 2166 patients were assigned to two groups (2-examination: 1087, 1-examination: 1079). Overall, we detected 29 AN in 28 patients at follow-up colonoscopy in both groups. On per-protocol analysis (701 in 2-examination vs 763 in 1-examination group), the incidence of AN was similar between the two groups (1.7% vs 2.1%, p=0.599). The results of the non-inferiority test were significant (p=0.017 in per-protocol, p=0.001 in intention-to-treat analysis). NP-CRNs composed of dominantly of the detected AN (62%, 18/29), and most of them were classified into laterally spreading tumour non-granular type (83%, 15/18).ConclusionAfter a two-round baseline colonoscopy, follow-up colonoscopy at 3 years detected AN, including NP-CRNs, as effectively as follow-up colonoscopies performed after 1 and 3 years.

Effective use of image-enhanced endoscopy and endoscopic submucosal dissection for multiple flat non-polypoid colorectal neoplasms

“…Non-polypoid colorectal neoplasms are the precursors of post-colonoscopy colorectal cancers (PCCRCs) [1], but can easily be overlooked because of their appearance. Therefore, early detection and treatment of laterally spreading tumors, non-granular type (LST-NGs) and 0-IIb lesions are important for preventing PCCRC.…”

Expectations for and challenges in population‐based endoscopic gastric and colorectal cancer screening

“…When considering whether an examination method can be applied to cancer screening, basic research is required to determine its accuracy and detection power. Therefore, data from the Akita pop‐colon trial, 8 the Nii‐jima/Oshima study, 12 and the Japan Polyp Study cohort 13 will likely be beneficial when revising guidelines. However, the following issues need to be resolved before population‐based TCS screening can be implemented: ensuring TCS safety and quality; processing capacity; medical‐economic assessments; adherence; and creating a TCS screening database 14 …”

Risk of metachronous neoplastic lesions during post‐polypectomy surveillance in individuals with advanced colorectal neoplasia at initial screening colonoscopy

“…The presence of advanced histology (HGD, cancer), number of neoplastic lesions (ACN, adenomas), size of ACN, presence of a right-sided serrated lesion sized ≥ 10 mm, presence of laterally spreading tumor (LST), and presence of LST without any granules (LST-non granular type; LST-NG) were examined as factors of screening colonoscopy findings because these factors were reported to be potentially associated with metachronous colorectal neoplasia. [4][5][6][7]22,24,25 The Cox proportional hazards model was also used for clinically relevant factors (the presence of advanced histology at baseline, the number of neoplastic lesions at baseline, age, sex, smoking, and CRC family history) and was only performed for the secondary outcome, considering the number of events. [4][5][6][7][13][14][15]22,24,25 Statistical analyses were conducted using SPSS software, version 26.0 (IBM, Armonk, NY) and EZR, version 1.53 (Saitama Medical Center, Jichi Medical University, Japan).…”

“…[4][5][6][7]22,24,25 The Cox proportional hazards model was also used for clinically relevant factors (the presence of advanced histology at baseline, the number of neoplastic lesions at baseline, age, sex, smoking, and CRC family history) and was only performed for the secondary outcome, considering the number of events. [4][5][6][7][13][14][15]22,24,25 Statistical analyses were conducted using SPSS software, version 26.0 (IBM, Armonk, NY) and EZR, version 1.53 (Saitama Medical Center, Jichi Medical University, Japan). 26…”