Unmasking early colorectal cancer clues: in silico and in vitro investigation of downregulated IGF2, SOCS1, MLH1, and CACNA1G in SSA polyps.

BACKGROUND AND AIM: Colorectal cancer (CRC) originates from pre-existing polyps in the colon. The development of different subtypes of CRC is influenced by various genetic and epigenetic characteristics. CpG island methylator phenotype (CIMP) is found in about 15-20% of sporadic CRCs and is associated with hypermethylation of certain gene promoters. This study aims to find prognostic genes and compare their expression and methylation status as potential biomarkers in patients with serrated sessile adenomas/polyps (SSAP) and CRC, in order to evaluate which, one is a better predictor of disease. METHOD: This study employed a multi-phase approach to investigate genes associated with CRC and SSAP. Initially, two gene expression datasets were analyzed using R and Limma package to identify differentially expressed genes (DEGs). Venn diagram analysis further refined the selection, revealing four genes from the Weissenberg panel with significant changes. These genes, underwent thorough in silico evaluations. Once confirmed, they proceeded to wet lab experimentation, focusing on expression and methylation status. This comprehensive methodology ensured a robust examination of the genes involved in CRC and SSAP. RESULT: This study identified cancer-specific genes, with 8,351 and 1,769 genes specifically down-regulated in SSAP and CRC tissues, respectively. The down-regulated genes were associated with cell adhesion, negative regulation of cell proliferation, and drug response. Four highly downregulated genes in the Weissenberg panel, including CACNA1G, IGF2, MLH1, and SOCS1. In vitro analysis showed that they are hypermethylated in both SSAP and CRC samples while their expressions decreased only in CRC samples. CONCLUSION: This suggests that the decrease in gene expression could help determine whether a polyp will become cancerous. Using both methylation status and gene expression status of genes in the Weissenberg panel in prognostic tests may lead to better prognoses for patients.

A practical guide to serrated appendiceal lesions.

Several neoplastic and non-neoplastic proliferations of the appendix can show varying degrees of serrated epithelial architecture. Of these, diffuse mucosal hyperplasia is most common, followed in frequency by low-grade mucinous and serrated neoplasms. It is important to distinguish serrated appendiceal neoplasms from their potential mimics because these entities may be managed differently. Diffuse mucosal hyperplasia is a non-neoplastic change that usually develops in the setting of resolving appendicitis and requires no further therapy or surveillance, and serrated neoplasms confined to the mucosa are adequately treated by appendectomy alone. On the other hand, low-grade appendiceal mucinous neoplasms may require surveillance, and those with extra-appendiceal spread differ from adenocarcinomas arising from serrated neoplasms with respect to both treatment and prognosis. Low-grade mucinous neoplasms in the peritoneum are frequently amenable to peritoneum-directed therapies alone, while adenocarcinomas derived from serrated neoplasms often spread to both regional lymph nodes and the peritoneum, potentially requiring right colectomy and systemic chemotherapy. The purpose of this review is to summarize the literature regarding the clinical and pathologic features of appendiceal lesions that show epithelial serration and provide the reader with helpful tips to distinguish serrated neoplasms from their mimics.

Detection of sessile serrated adenoma using artificial intelligence-enhanced endoscopy: an Asian perspective.

BACKGROUND: As the serrated pathway has gained prominence as an alternative colorectal carcinogenesis pathway, sessile serrated adenomas or polyps (SSA/P) have been highlighted as lesions to rule out during colonoscopy. These lesions are however morphologically difficult to detect on endoscopy and can be mistaken for hyperplastic polyps due to similar endoscopic features. With the underlying nature of rapid progression and malignant transformation, interval cancer is a likely consequence of undetected or overlooked SSA/P. Real-time artificial intelligence (AI)-assisted colonoscopy via the computer-assisted detection system (CADe) is an increasingly useful tool in improving adenoma detection rate by providing a second eye during the procedure. In this article, we describe a guide through a video to illustrate the detection of SSA/P during AI-assisted colonoscopy. METHODS: Consultant-grade endoscopists utilized real-time AI-assisted colonoscopy device, as part of a larger prospective study, to detect suspicious lesions which were later histopathologically confirmed to be SSA/P. RESULTS: All lesions were picked up by the CADe where a real-time green box highlighted suspicious polyps to the clinician. Three SSA/P of varying morphology are described with reference to classical SSA/P features and with comparison to the features of the hyperplastic polyp found in our study. All three SSA/P observed are in keeping with the JNET Classification (Type 1). CONCLUSION: In conclusion, CADe is a most useful aid to clinicians during endoscopy in the detection of SSA/P but must be complemented with factors such as good endoscopy skill and bowel prep for effective detection, and biopsy coupled with subsequent accurate histological diagnosis.

Clinical and endoscopic characteristics of colorectal sessile serrated lesions with or without dysplasia/carcinoma: A systematic review and meta-analysis.

OBJECTIVE: We aimed to compare the clinical and endoscopic characteristics of sessile serrated lesions (SSLs) with dysplasia/carcinoma (SSLD/Cs) and SSLs without dysplasia in this systematic review and meta-analysis. METHODS: MEDLINE, EMBASE, and Cochrane Library databases and Clinicaltrials.gov were searched for relevant studies published up to August 28, 2023. The primary outcome was lesion size in SSLD/Cs and SSLs without dysplasia. The secondary outcomes included risk of dysplasia/carcinoma, morphology (classified based on the Paris classification), and lesion features such as mucus cap and nodules/protrusions in the two groups. RESULTS: Thirteen studies with 14 381 patients were included. The proportion of SSLD/Cs ≥10 mm was significantly higher than that of SSLs without dysplasia (odds ratio [OR] 3.82, 95% confidence interval [CI] 1.21-12.02, p = 0.02). There was no significant difference in the risk of dysplasia/carcinoma between the proximal (OR 0.80, 95% CI 0.57-1.14) and distal colon (OR 1.25, 95% CI 0.88-1.77, p = 0.21). The 0-Ip (OR 2.47, 95% CI 1.50-4.09) and 0-IIa + Is (OR 10.38, 95% CI 3.08-34.98) morphologies were more prevalent among SSLD/Cs, whereas the 0-IIa morphology (OR 0.38, 95% CI 0.22-0.65) was more prevalent among SSLs without dysplasia (all p < 0.001). Furthermore, mucus cap (OR 0.61, 95% CI 0.42-0.89, p = 0.01) was more common among SSLs without dysplasia, whereas nodules/protrusions (OR 7.80, 95% CI 3.07-19.85, p < 0.001) were more common in SSLD/Cs. CONCLUSION: SSLs >10 mm, 0-Ip or 0-IIa + Is morphologies, and those with nodules/protrusions are significantly associated with dysplasia/carcinoma.