Higher risk of advanced histology in adenoma less than 10 mm in fecal immunochemical test screening: Implication for management

Circulating small extracellular vesicle RNA profiling for the detection of T1a stage colorectal cancer and precancerous advanced adenoma

It takes more than 20 years for normal colorectal mucosa to develop into metastatic carcinoma. The long time window provides a golden opportunity for early detection to terminate the malignant progression. Here, we aim to enable liquid biopsy of T1a stage colorectal cancer (CRC) and precancerous advanced adenoma (AA) by profiling circulating small extracellular vesicle (sEV)-derived RNAs. We exhibited a full RNA landscape for the circulating sEVs isolated from 60 participants. A total of 58,333 annotated RNAs were detected from plasma sEVs, among which 1,615 and 888 sEV-RNAs were found differentially expressed in plasma from T1a stage CRC and AA compared to normal controls (NC). Then we further categorized these sEV-RNAs into six modules by a weighted gene coexpression network analysis and constructed a 60-gene t-SNE model consisting of the top 10 RNAs of each module that could well distinguish T1a stage CRC/AA from NC samples. Some sEV-RNAs were also identified as indicators of specific endoscopic and morphological features of different colorectal lesions. The top-ranked biomarkers were further verified by RT-qPCR, proving that these candidate sEV-RNAs successfully identified T1a stage CRC/AA from NC in another cohort of 124 participants. Finally, we adopted different algorithms to improve the performance of RT-qPCR-based models and successfully constructed an optimized classifier with 79.3% specificity and 99.0% sensitivity. In conclusion, circulating sEVs of T1a stage CRC and AA patients have distinct RNA profiles, which successfully enable the detection of both T1a stage CRC and AA via liquid biopsy.

The Diagnostic Accuracy of a Fecal Immunochemical Test in Detecting Colorectal Cancer and Advanced Precancerous Colorectal Neoplasia in Patients with Iron Deficiency: A Protocol for Systematic Review and Meta-Analysis

Background. Iron deficiency (ID) is a common micronutrient deficiency and the leading cause of anemia worldwide. ID can be caused by chronic occult blood loss from colorectal neoplasia including colorectal cancer (CRC) and advanced precancerous colorectal lesions. Current guidelines recommend colonoscopy in both men and postmenopausal women presenting with ID anemia (IDA). However, there is controversy on the investigation of patients presenting with a lower risk of CRC including younger women with ID and those with nonanemic ID (NAID). There is a need for a triaging tool to identify which ID patients may benefit from colonoscopy. The fecal immunochemical test (FIT) is sensitive for CRC screening in an asymptomatic population, but its role in ID patients is unclear. The aim of this study is to conduct a systematic review to determine the diagnostic accuracy of FIT for detecting CRC and advanced precancerous neoplasia in individuals presenting with ID with or without anemia. Methods and Analysis. This protocol conforms with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols and Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy. A comprehensive search of the MEDLINE, Embase, and Web of Science databases will be undertaken for studies published after 2010 which involve patients with ID, who completed a FIT in the 6 months prior to colonoscopy, with FIT sensitivity and specificity calculated against the reference standard colonoscopy. The search will be limited to studies conducted after 2010 to reduce variability in colonoscopy quality. Risk of bias assessment will be conducted using the Quality Assessment of Diagnostic Accuracy Studies version 2. FIT sensitivity and specificity will be the primary measure of diagnostic accuracy, and data will be analysed using a random effects meta-analysis. Discussion. This review and meta-analysis will be the first to systematically explore the value of the FIT as a triaging tool for patients with ID. This trial is registered with CRD42022367162.

Cold Versus Hot Snare Polypectomy for Small Colorectal Polyps : A Pragmatic Randomized Controlled Trial

BACKGROUND

Although cold snare polypectomy (CSP) is considered effective in reducing delayed postpolypectomy bleeding risk, direct evidence supporting its safety in the general population remains lacking.

OBJECTIVE

To clarify whether CSP would reduce delayed bleeding risk after polypectomy compared with hot snare polypectomy (HSP) in the general population.

DESIGN

Multicenter randomized controlled study. (ClinicalTrials.gov: NCT03373136).

SETTING

6 sites in Taiwan, July 2018 through July 2020.

PARTICIPANTS

Participants aged 40 years or older with polyps of 4 to 10 mm.

INTERVENTION

CSP or HSP to remove polyps of 4 to 10 mm.

MEASUREMENTS

The primary outcome was the delayed bleeding rate within 14 days after polypectomy. Severe bleeding was defined as a decrease in hemoglobin concentration of 20 g/L or more, requiring transfusion or hemostasis. Secondary outcomes included mean polypectomy time, successful tissue retrieval, en bloc resection, complete histologic resection, and emergency service visits.

RESULTS

A total of 4270 participants were randomly assigned (2137 to CSP and 2133 to HSP). Eight patients (0.4%) in the CSP group and 31 (1.5%) in the HSP group had delayed bleeding (risk difference, -1.1% [95% CI, -1.7% to -0.5%]). Severe delayed bleeding was also lower in the CSP group (1 [0.05%] vs. 8 [0.4%] events; risk difference, -0.3% [CI, -0.6% to -0.05%]). Mean polypectomy time (119.0 vs. 162.9 seconds; difference in mean, -44.0 seconds [CI, -53.1 to -34.9 seconds]) was shorter in the CSP group, although successful tissue retrieval, en bloc resection, and complete histologic resection did not differ. The CSP group had fewer emergency service visits than the HSP group (4 [0.2%] vs. 13 [0.6%] visits; risk difference, -0.4% [CI, -0.8% to -0.04%]).

LIMITATION

An open-label, single-blind trial.

CONCLUSION

Compared with HSP, CSP for small colorectal polyps significantly reduces the risk for delayed postpolypectomy bleeding, including severe events.

PRIMARY FUNDING SOURCE

Boston Scientific Corporation.

Third Asia-Pacific consensus recommendations on colorectal cancer screening and postpolypectomy surveillance

The Asia-Pacific region has the largest number of cases of colorectal cancer (CRC) and one of the highest levels of mortality due to this condition in the world. Since the publishing of two consensus recommendations in 2008 and 2015, significant advancements have been made in our knowledge of epidemiology, pathology and the natural history of the adenoma-carcinoma progression. Based on the most updated epidemiological and clinical studies in this region, considering literature from international studies, and adopting the modified Delphi process, the Asia-Pacific Working Group on Colorectal Cancer Screening has updated and revised their recommendations on (1) screening methods and preferred strategies; (2) age for starting and terminating screening for CRC; (3) screening for individuals with a family history of CRC or advanced adenoma; (4) surveillance for those with adenomas; (5) screening and surveillance for sessile serrated lesions and (6) quality assurance of screening programmes. Thirteen countries/regions in the Asia-Pacific region were represented in this exercise. International advisors from North America and Europe were invited to participate.