MOLECULAR-GENETIC CRITERIA AND PROSPECTIVE BIOMARKERS OF SERRATED ADENOMAS OF COLORECTAL LOCALIZATION

A retrospective analysis of the database of patients with histologically verified serrated adenomas of the colon was carried out as part of an observational study. Inclusion criteria: patients with serrated colon adenomas who underwent a molecular genetic study to detect mutations and further sequencing 16 sRNAs of intestinal microbiota from January 2021 to October 2021. The exclusion criteria: patients with a primary tumor of the colon who had previously received complex treatment, who had accompanying pathologies of the other organs and systems, which did not allow for the planned examination. According to the results of the study, BRAF mutations are diagnosed in half of the cases in serrated adenomas and in one-third of cases - KRAS mutations. As a result of a comparative analysis of the intestinal microbiome of young patients with serrated colon adenomas with summary statistical data on the presence of bacteria in the intestines of people from the Russian population; promising markers were found for the development of effective approaches for the early diagnosis of colorectal cancer.

Education and gastroenterology fellow knowledge about endoscopic mucosal resection of colon adenomas: a survey-based study

Background and study aims Endoscopic mucosal resection (EMR) is an effective way to remove large (> 2 cm) colon adenomas. Training about it has not been standardized in fellowship programs. This study was aimed at evaluating the education and knowledge of gastroenterology fellows about EMR of colorectal adenomas. Methods Participation in this survey was offered to 1730 gastroenterology fellows in the United States during the academic year 2019 to 2020. The survey assessed endoscopic mucosal resection training and knowledge and was approved and administered by the American College of Gastroenterology. Results A total of 163 fellows (9.4 %) completed the survey. Only 85 fellows (52.1 %) reported receiving formal education in endoscopic mucosal resection. Fellow confidence was lowest regarding knowing electrosurgery unit settings. Fewer fellows correctly identified Paris 0-IIb (79, 48.5 %; P < 0.0001) or NICE I (114, 69.9 %; P < 0.01) lesions as compared to other Paris and NICE III lesions, respectively. Only 73 (44.8 %) and 93 fellows (57.1 %) arranged steps of EMR in the correct order and identified the correct type of current used for resection, respectively. Training year, male sex, and provision of advanced endoscopy rotations during fellowship were associated with a higher knowledge score for EMR. Conclusions Nearly half of all fellows reported no formal education in EMR and incorrectly ordered its steps. Adenoma assessment by Paris and NICE classifications and electrosurgery unit settings were the most prominent knowledge deficiencies. Incorporation of standardized training about EMR with inclusion of advanced endoscopy rotations appears to be an important educational opportunity during gastroenterology fellowship.

Endoscopic mucosal resection and conventional polypectomy in colon adenomas

Aim: to compare the early and long-term results of endoscopic mucosal resection (EMR) and conventional polypectomy for benign epithelial colon neoplasmsPatients and methods: the retrospective study included 344 patients with histologically verified adenomas of the size of up to 40 mm in the colon, who underwent EMR or conventional polypectomy. Mucosectomy (EMR) was performed in 207 patients, while conventional polypectomy was performed in 137.Results: there were no significant differences in the postoperative morbidity rates between the methods (OR = 1.8; 95% CI = 0.7–4.8, p = 0.3). Fragmentation significantly more often occurred in the group of conventional polypectomy (OR = 3.5; 95% CI = 2.3–5.5, p = 0.001, especially when the size of the neoplasm was over 1 cm (OR = 3.1; 95% CI = 1.1–8.9 = 0.037). Recurrence occurred in 19/173 (10.9%) in 12 (8.3%) patients of the EMR group. In the polypectomy group, recurrence developed in 22 (23.1%) patients, in 24/108 (22.2%) cases at the site of the postoperative scar. It was found that the adenoma recurrence in the area of endoscopic excision occurs significantly more often after conventional polypectomy (OR = 2.3; 95% CI = 1.2–4.4; p = 0.016).Conclusion: EMR and conventional polypectomy both are the safe methods with low morbidity rates. However, the EMR is the preferred method of endoscopic excision for adenomas larger than 1 cm due to the fact that it allows for deeper and more complete resection of the tissue than conventional polypectomy.

ErbB Receptor Stimulation Is Required for Mouse Colon Adenoma Organoids to Form Crypts

The majority of colon adenomas harbor genetic mutations in the APC gene. APC mutation leads to changes in Wnt signalling and cell-cell adhesion: as a consequence, intestinal crypt budding increases and the excess crypts accumulate to form adenomas that progress to colon cancer. When cultured with Wnt, R-spondin, EGF, Noggin, myofibroblast conditioned medium and Matrigel, crypts from normal mouse colon mucosa form crypt-producing organoids and can be passaged continuously. Under the same culture and passage conditions, crypts isolated from colon adenomas derived from Apcmin/+ mice typically grow as spheroidal cysts and do not produce crypts. The adenoma organoid growth requires EGF, but not Wnt, R-spondin or Noggin. However, when mouse colon adenoma spheroids are grown for more than 10 days in the presence of EGF, crypt formation occurs. EGF, EREG, β-cellulin, Neuregulin-1 or AREG are sufficient for initiating crypt formation, however, neuregulin-1 is more potent than the other EGF-family members. EGFR and ErbB2 inhibitors both prevent crypt formation in adenoma cultures. Either EGFR:ErbB2 or ErbB3:ErbB2 signalling is sufficient to initiate adenoma crypt budding and elongation. ErbB2 inhibitors may provide a therapeutic avenue for controlling and ablating colon adenomas.

Risk factors for colon adenomas recurrence after endoscopic mucosal resection

Aim: to identify risk factors for neoplasms recurrence removed by endoscopic mucosal resection (EMR).Patients and methods: the single-center retrospective observational study included 207 patients with 260 benign colon neoplasms. There were 95 (45.9%) males and 112 (54.1%) females. The median age of the patients was 67 (27-80) years. The results obtained were assessed using following criteria: morbidity rate, complication type, hospital stay, tumor site, number of neoplasms in colon, lateral growth, fragmentation rate, technical difficulties (mucosal fold convergence)during surgery, grade of dysplasia, recurrence rate.Results: intraoperative fragmentation of the neoplasms during mucosectomy occurred in 48/260 (18.5%) cases. Postoperative complications within the period of up to 30 days occurred in 13/207 (6.3%) patients. The most frequent 9 (4.2%) postoperative complication arising after mucosectomy was post-polypectomy syndrome. Another 4 (2.0%) patients produced bleeding after the surgery, which required repeated endoscopic procedure. No mortality occurred. The tumor size exceeding 25 mm (Exp (B) = 0.179; 95% CI = 0.05-0.7; p = 0.014), severe dysplasia (Exp (B) = 0.113; 95% CI = 0.03-0.4; p = 0.001) and fold convergence (Exp (B) = 0.2; 95% CI = 0.07-0.7; p = 0.015) are independent risk factors for disease recurrence.Conclusion: mucosectomy is indicated for colon adenomas if its size does not exceed 25 mm and can be removed en bloc.