The aim of this study was to determine the characteristics of Russian patients with microsatellite instability (MSI) tumors. MSI in the tumor was determined in 514 patients with colon cancer using PCR and subsequent fragment analysis for five markers (NR21, NR24, BAT25, BAT26, and NR27). In the presence of microsatellite instability, the mismatch repair (MMR) system genes were examined using the NGS and MLPA methods to establish the diagnosis of Lynch syndrome. The overall frequency of MSI tumors was 15%: at stage I—19% (9/48), at stage II—21% (44/213), at stage III—16% (26/160), and at stage IV—2% (2/93). Patients with MSI tumors differed in the age of diagnosis, tumor localization, time of cancer recurrence, and stage of the disease. The overall and disease-free survival of patients whose tumors had MSI status was higher than that of patients with microsatellite-stable status, p = 0.04 and p = 0.02, respectively. Analysis of overall and disease-free survival of patients with Lynch syndrome and patients with sporadic colon cancer, but with MSI status, did not reveal significant differences, p = 0.52 and p = 0.24, respectively. The age of patients with Lynch syndrome was significantly younger than that of patients with sporadic colon cancer whose tumors had MSI status (p < 0.001).

Colorectal cancer (CRC) is one of the most common malignancies in the world. It's estimated about 1.8 M new CRC cases worldwide per year. A somatic mutation in the BRAF gene in the tumor is a negative prognostic factor. This work is aimed at studying the clinical and genetic characteristics of Russian CRC patients with the BRAF mutation. The BRAF mutations were studied by Sanger sequencing and digital droplet PCR in 489 patients and found in 34 (7%) cases. The most common mutation was p.V600E (82%). Also, rare variants were found: p.K601E, p.N581I, p.G596R, and p.D594N. All the patients with rare mutations were characterized by an unfavorable prognosis of the disease. The clinical features of the patients with BRAF mutations in the study include the predominant primary tumor site in the rectum, in addition to the right colon. Then, most of the cases were diagnosed in the advanced stages of the disease and were represented by high-grade adenocarcinomas. This article demonstrates the feasibility of analysis of the entire exon 15 of BRAF gene in CRC patients regardless of tumor localization.

Purpose: to study the etiological structure and incidence rate of various genesis optical neuropathies (ON) according to the own observation data. Material and methods. The study is based on the data analysis from a survey of 658 patients (982 eyes) with ON. The results of routine physical examination of all patients were analyzed to determine the genesis of ON. Results. The most common cases of ON were ischemic ON (31.2 % of all cases), as well as optic neuritis (18.3 % of cases). The anterior optic pathway tumor or infiltrative lesions were detected in 9.9 %, dysthyroid ON was found in 7.2 %. Acute and chronic ON with the optic nerve drusen accounted for 12.4 % of all cases of ON, was found in 60.5 % of all patients with the optic nerve drusen. Hereditary ON was found in 10 % of all cases of ON, toxic - in 4,3 % as a result of acute and chronic alcohol intoxication, chronic narcotic poisoning, drug poisoning. Traumatic ON was found in 6.7 % of all cases of ON. Conclusions. The causes of ON are diverse, vary from innate changes to diseases of the optic nerve as a result of serious therapeutic and neurosurgical pathology, which threaten not only the ophthalmologic, but also the life prediction. The patient thorough clinical study is required to determine the disease genesis at the time of ON symptoms identifying.