[One thousand endoscopic submucosal dissections. Experience of the national center]. / Odna tysyacha endoskopicheskikh podslizistykh dissektsii. Opyt natsional'nogo tsentra.

BACKGROUND: Endoscopic submucosal dissection (ESD) is a perspective method of organ-sparing treatment of benign colon tumors. MATERIAL AND METHODS: The study included 1.000 patients with colon neoplasms who underwent ESD between October 2016 and October 2021. All surgeries were performed under intravenous sedation. RESULTS: Mean dimension of tumors was 3.4 cm, median of surgery time - 51 (31; 101) minutes. Conversion of endoscopic approach occurred in 7.6% of cases. The main cause of conversion was unsatisfactory lifting in submucosal injection process. Incidence of en bloc and R0 resections was 84.1% and 68.3%, respectively. Postoperative morbidity was 2.9% that correlates with the world literature data. CONCLUSION: Endoscopic submucosal dissection is an effective and safe method for benign colon neoplasms. Considering high incidence of en bloc resection and low rate of local recurrence in benign neoplasms, further research of efficacy and safety of ESD in early colon cancer is needed.

[Pilot clinical and genetic study of Russian patients with Peutz-Jeghers syndrome].

Peutz-Jeghers syndrome is a rare hereditary syndrome characterized by presence of hamartoma polyps in intestinal tract and usually by mucocutaneous pigmentation. Clinical-genetic characteristics of Russian patients with Peutz-Jeghers syndrome were studied for the first time. Four germline mutations in STK11gene were found in probands from six families and three of them had not been described previously. Clinical pattern of disease in Russian patients included: frequent polyposis of colon and stomach (62,5% and 75%, respectively) along with small bowel; frequent presence of malignant tumors (62,5%). These clinical aspects can help physicians to find out Peutz-Jeghers syndrome. Molecular-genetic testing of individuals should be recommended.

[Early Rectal Cancer: Can Transanal Endoscopic Microsurgery (TEM) Become the Standard Treatment?]

Aim: Transanal endoscopic microsurgery (TEM) is a main treatment technique for rectal adenomas, but can also be used for selected malignant tumors. This study presents TEM experience. Methods: The study enrolled patients with rectal adenomas, and selected adenocarcinomas. Preoperative work-up included: digital rectal examination, rectoscopy with biopsy, colonoscopy, EUS, pelvic MRI. Results: Three hundred and thirty patients [mean age of 61,4±10 (33­88)] underwent TEM. The mean size ± SD of tumors was 3.2±1.2 cm (0.6­10.0). Mean distance from anal verge was 6.7±2.6 cm (2.0­14.0). Preoperative biopsy revealed: adenoma ­ 263/330 (79,7%), adenocarcinoma ­ 67/330 (20,3%). The median operating time was 40 (15­220) min. Tumor-free margins were obtained in all operative specimens. In 5/330 (1.5%) cases tumors were fragmented. The morbidity rate was 19/330 (5.7%). Pathological investigation revealed: adenoma in 192/330 (58.1%) cases, adenocarcinoma stage Tis, T1, T2 and T3 in 138/330 (41.9%). Median follow-up lasted for 24 (1­57) months. Five patients (2.0%) with adenoma and four patients (5.2%) with adenocarcinoma had local recurrence. Conclusion: Transanal endoscopic microsurgery for rectal adenomas and selected malignant tumors is associated with low morbidity and low recurrents rates.

[Possibilities of transanal endoscopic microsurgery: the experience of 202 operations].

Transanal endoscopic microsurgery (TEM/TEO) is a standard treatment for rectal adenomas but can also be used for selected malignant tumors. Rectal adenomas, selected adenocarcinomas and carcinoids were chosen for operations. Preoperative work-up included: digital rectal examination, rectoscopy with biopsy, colonoscopy, EUS, pelvic CT (MRI). Two hundred and two patients [mean age of 62.4 ± 10.3 (33-86)] had TEO. The mean size ± SD of tumors was 3.2 ± 1.4 cm (0.6-8.0). Mean distance from anal verge and dental line was 7.1 ± 2.4 cm (2.5-14.0) and 4.6 ± 2.6 cm (0.5-12.0), respectively. Preoperative biopsy revealed: adenoma--156/202 (77.2%), adenocarcinoma--39/202 (19.3%) and carcinoid--7/202 (3.5%). The median operating time was 40 (20-180) min. Tumor-free margins were obtained in 200/202 (99%) operative specimens, 2/202 (1.0%) cases tumors were fragmented. Morbidity was 7/202 (3.5%). Pathological investigation revealed: adenoma in 109/202 (54.0%) cases, adenocarcinoma stage Tis, T1, T2 and T3 in 86/202 (42.5%), carcinoid in 5/202 (2.5%), neurilemoma in 1/202 (0.5%), neurofibroma in 1/202 (0.5%). One hundred and two patients had follow-up (95%). Median follow-up at 20 (1-41) months; 3/192 patients with adenocarcinoma, 1/192 patient with adenoma and 1/192 patient with carcinoid had local recurrence. Thus, transanal endoscopic microsurgery for rectal adenomas and selected malignant tumors is associated with low morbidity and low recurrents rates.

CD133+ human colorectal adenocarcinoma cells are resistant to staining with fluorescent dyes used for analysis of ABC transporter activities.

Flow cytometry measurement of the expression of surface marker CD133 simultaneously with the analysis of fluorescent dye exclusion was performed in order to develop new methods for detection of cancer stem cell populations in tumor tissue samples from patients with colorectal adenocarcinoma. No correlation was found between the count of CD133(+) cancer cells and the volume of the "population" formed from cells actively pumping off the fluorescent dye. On the other hand, the fluorescence distribution plot showed predominant location of CD133(+) cancer cells among cells stained with neither DyeCycle Violet DNA-binding dye, nor rhodamine 123 mitochondrial dye. These cells did not show the properties of the classical "side population", because they did not shift to the area of stained cell after treatment with ionic channel blocker verapamil.

Total mesorectal excision with water-jet dissection in patients with rectal cancer: surgical and morphological aspects.

AIM: This publication will describe our own experience of using the ERBEJET2(®) water-jet dissector during surgical interventions for rectal cancer. METHOD: We utilized the water-jet dissection technique to obtain tissue specimens in 10 patients with rectal cancer. All patients thus underwent nerve-sparing low anterior resection of the rectum along with para-aortic lymphadenectomy. No intraoperative complications were registered. The postoperative period went uncomplicated in all patients. No dysuria was observed. Obtained tissue specimens were examined morphologically. Macroscopic examination included assessments of the preservation of the rectal fascia propria and the amount of cellular tissue along the anterior, posterior, and lateral surfaces of the rectum. We performed microscopy of the circumferential resection margin to characterize the surgical clearance and the intensity and depth of damage to the mesorectal tissue. On morphological examination, the quality of mesorectal excision was found to be good (Grade 3) in all 10 patients. RESULTS: As the results of our study demonstrate, the depth of lateral tissue damage is minimal with the water-jet dissector. CONCLUSION: Water-jet dissectors have their own place in the long list of armamentarium used in surgical interventions performed for rectal cancer and contribute to improving oncological and functional outcomes of surgical treatment in this patient population.

Subpopulation of colorectal adenocarcinoma cells co-expressing CD133 and cancer stem cells markers of other tumors.

Co-expression of colorectal adenocarcinoma cancer stem cells marker CD133 and a set of surface molecules described in published reports as possible cancer stem cell markers of other solid tumors was analyzed by flow cytometry. Minor cell populations expressing CD29, CD34, CD90, and CD117 against the background of CD133 expression were detected in cancer cells suspensions from the patients with colorectal adenocarcinoma. Our findings suggest that these markers can be used as additional markers of cancer stem cells of human colorectal adenocarcinoma.

Detection of minor subpopulations of colorectal adenocarcinoma cells expressing cancer stem cell markers.

The expression of puitative surface molecular markers of cancer stem cells on human colorectal adenocarcinoma cells was analyzed by flow cytofluorometry. Cell subpopulations expressing markers of epithelial and malignant cells and stem cell markers were identified. Four minor subpopulations with CD24(+)/CD133(+), CD44(+)/CD133(+), CD90(+)/CD71(+), or CD90(+)/CD24(+) phenotypes meeting this requirement were detected; presumably, those were cancer stem cell subpopulations. These results extend our knowledge on heterogeneity of human colorectal adenocarcinoma cell population and outline new trends of research of cancer stem cell phenotype in these tumors.