Pilot Experiment on Non-Invasive Non-Thermal Disintegration of Human Mucinous Breast Carcinoma Ex Vivo Using Boiling Histotripsy.

We present the results of a pilot study demonstrating the feasibility of non-invasive non-thermal disintegration of human mucinous carcinoma of the breast ex vivo using sequences of high-intensity focused ultrasound pulses in boiling histotripsy regimen. The target volume was sonicated by focusing ultrasound pulses (n=20) of 1.5 MHz frequency, 10-msec duration and 1-sec pulse repetition period, 517 W acoustic power within the pulse, and 103 MPa shock front amplitude at the focus into each node of a volumetric grid 4×4×1 mm. Sonication was visualized and controlled using B-mode ultrasound imaging, total time of the treatment was 21 min. Histological hematoxylin and eosin and Masson's trichrome staining revealed the absence of tumor elements in the treated region confirming destruction of cancer cells and their nuclei after boiling histotripsy procedure.

[Prognostic significance of PD-L1 expression as a potential predictor of survival in gastric cancer]. / Prognosticheskaya znachimost' ekspressii PD-L1 kak potentsial'nogo prediktora vyzhivaemosti pri rake zheludka.

BACKGROUND: Currently, PD-L1 expression in patients with tumors of various localizations is being actively studied. Studies on the expression of PD-L1 detected by clones SP142 and SP263 in gastric cancer (for the drugs atezolizumab and durvalumab, respectively) are rare in the literature. The prognostic role of PD-L1 expression in patients who were not treated with immune checkpoint inhibitors has also not been investigated. OBJECTIVE: To determine the expression level of PD-L1 (clones SP263 and SP142, Roche Ventana) in gastric cancer specimens and evaluate its effect on overall survival in patients who did not receive adjuvant therapy with immune checkpoint inhibitors. MATERIAL AND METHODS: The study included 131 patients with a verified diagnosis of gastric cancer. The material obtained from 127 patients was stained with antibodies to PD-L1 SP263, and from 126 patients - with antibodies to PD-L1 SP142. A multivariate Cox regression model with Wald's step-by-step exclusion algorithm was used to evaluate predictors of survival. RESULTS: The total five-year survival rate of patients in the PD-L1-negative tumor group was significantly lower than the total five-year survival rate of patients in the PD-L1-positive tumor group, which was 50.0% and 40.0% also for both clones (p=0.027). An increase in the expression of PD-L1 clone SP263, determined by both the CPS and TPS method, reduces the chances of death by 1.35 times (p=0.02) and 1.61 times (p=0.004), respectively. An increase in the expression of PD-L1 clone SP142, determined by the CPS method, reduces the chances of death by 1.54 times (p=0.005). CONCLUSION: The survival rate of patients in the group of PD-L1-positive tumors is significantly higher than in patients in the group of PD-L1-negative tumors. Elevated PD-L1 expression, as assessed by the SP263 and SP142 clones, is an important prognostic marker that predicts a higher chance of overall survival for patients, even though these patients are not receiving immune checkpoint inhibitors adjuvant therapy.

[Issues of legal responsibility of the pathologist]. / Voprosy yuridicheskoi otvetstvennosti patologoanatoma.

Medical care refers to a risky type of activity, since as a result of its provision, harm to the patient's health may be caused and prerequisites for the onset of legal (civil, disciplinary, administrative and criminal) liability may arise. The legal liability of a pathologist in the event of an incorrect diagnosis by the attending physician on the basis of an incorrect conclusion of the pathologist may occur due to violations due to low qualifications, frivolity, negligence, failure to comply with the rules, procedures for providing medical care, job descriptions, official duties. If the incorrect conclusion of the pathologist was of an objective nature (for example, in the case of an incorrect interpretation of a diagnostically difficult case), it should go beyond the scope of punishable shortcomings in the activities of the pathologist. The financial responsibility of a pathologist may occur when its burden is placed on a medical organization for harm caused to the life or health of a patient, due to the establishment, among other things, of the legality of the actions (inaction) of a medical worker with whom the medical organization is in an employment relationship. A medical organization, in case of satisfaction of the patient's claims by the court, as a rule, in a regression procedure, may involve the relevant medical worker who caused the harm in the issue of compensation, compensate for their financial and reputational losses. The most important thing in such cases is to resolve the issue of establishing the grounds for bringing a medical worker to responsibility.

Pilot ex vivo study on non-thermal ablation of human prostate adenocarcinoma tissue using boiling histotripsy.

Focused ultrasound technologies are of growing interest for noninvasive ablation of localized prostate cancer (PCa). Here we present the results of the first case study evaluating the feasibility of non-thermal mechanical ablation of human prostate adenocarcinoma tissue using the boiling histotripsy (BH) method on ex vivo tissue. High intensity focused ultrasound field was generated using a 1.5-MHz custom-made transducer with nominal F#=0.75. A sonication protocol of 734 W acoustic power, 10-ms long BH-pulses, 30 pulses per focal spot, 1 % duty cycle, and 1 mm distance between single foci was tested in an ex vivo human prostate tissue sample containing PCa. The protocol used here has been successfully applied in the previous BH studies for mechanical disintegration of ex vivo prostatic human tissue with benign hyperplasia. BH treatment was monitored using B-mode ultrasound. Post-treatment histologic analysis demonstrated BH produced liquefaction of the targeted tissue volume. BH treated benign prostate parenchyma and PCa had similar tissue fractionation into subcellular fragments. The results of the study demonstrated that PCa tumor tissue can be mechanically ablated using the BH method. Further studies will aim on optimizing protocol parameters to accelerate treatment while maintaining complete destruction of the targeted tissue volume into subcellular debris.

Identification of Cancer-Associated Fibroblasts in Metastatic Lymph Nodes of Colorectal Carcinoma.

Cancer-associated fibroblasts (CAF) are a heterogeneous group of tumor microenvironment cells that are barely studied in metastatic lymph nodes. The presence of CAF in regional metastases of colorectal cancer was assessed by using SMA, PDGFRb, and POD markers; the obtained subpopulations were compared with the primary tumor. A total of 26 cases of colon adenocarcinoma with metastases to regional lymph nodes were studied. Duplex immunohistochemical detection (POD+SMA and PDGFRb+SMA) was carried out by the immunohistochemical method. In most cases, POD was absent in metastases (65.4%) and PDGFRb was present (88.5%). The POD and PDGFRb staining in the invasive edge of the tumor did not correlate with metastasis. Attention was drawn to the absence of POD and PDGFRb reactions in a blood vessel embolus, as well as to negative PDGFRb in metastasis in the presence of pronounced PDGFRb in the primary tumor in patients after neoadjuvant therapy.

[Mucins expression in gastric cancer: connection of MUC status with clinical, morphological and prognostic characteristics of the tumor]. / Ekspressiya mutsinov v rake zheludka: svyaz' MUC-statusa s kliniko-morfologicheskimi i prognosticheskimi kharakteristikami opukholi.

OBJECTIVE: Clarification of the prognostic value and relationship of MUC-phenotypes of gastric cancer with clinical and morphological parameters. MATERIAL AND METHODS: Surgical material from 310 patients with a verified diagnosis of gastric cancer was studied. Samples were immunohistochemically stained with antibodies to MUC2, CD10, MUC5AC. The results were compared with clinical and morphological characteristics of gastric cancer and patient survival data. RESULTS: The MUC-null and MUC-mix groups significantly differ in the prevalence of subtotal/total tumors from the MUC-I group (p=0.022 and p=0.007, respectively), where there are significantly fewer such tumors. Tubular tumors were more common in the MUC-null group compared to the MUC-G (p=0.026) and MUC-mix (p=0.006) groups, and there were fewer cases with the presence of "signet-ring" cells in the MUC-null group (p=0.000). When studying the discohesive histological type, the literature data on smaller tumor sizes and a lower frequency of lymph node metastasis for MUC-G status were not confirmed, but a more frequent proximal localization of MUC-I tumors was found (p=0.003). No statistically significant differences in survival were found in the analysis of the total sample. Differences in survival were found only in discohesive cancers, where the best survival was recorded for the MUC-null group, and the worst for the MUC-mix group (p=0.022). MUC status is not an independent predictor of gastric cancer (HR=1.662, p=0.093). CONCLUSION: Between tumors with different MUC statuses, there were differences in localization and belonging to individual histological types. Significant differences in survival were found only for discohesive cancers with MUC-null and MUC-mix statuses. Separation of gastric cancers according to MUC status may have only limited predictive value in selected histological forms of cancer.

[Microsatellite instability in gastric cancer is a predictor of a favorable prognosis]. / Mikrosatellitnaya nestabil'nost' v rake zheludka ­ prediktor blagopriyatnogo prognoza.

OBJECTIVE: Evaluation of the frequency of microsatellite instability in gastric adenocarcinomas in patients of the Russian Federation, determination of the relationship of microsatellite instability with clinical and morphological characteristics and the impact on the prognosis. MATERIAL AND METHODS: We used samples of surgical material from 310 patients with a verified diagnosis of gastric cancer. The age of the patients ranged from 22 to 85 years (mean 63 years). The median follow-up of patients was 83 months. Each sample was immunohistochemically stained with antibodies to microsatellite instability markers MLH1, MSH2, MSH6, and PMS2. The results were compared with the main clinical and morphological characteristics of gastric cancer and data on patient survival. RESULTS: The frequency of detection of MMR-negative tumors in the Russian population is 8.1% of all patients with gastric cancer. It was found that patients with MMR-negative gastric carcinomas are older (mean age 69 years, p=0.008). In this group predominates distal localization of tumors, type 2 according to R. Bormann classification (p=0.010), tubular histological type (p=0.010), intestinal subtype according to P. Lauren classification (p=0.003). There were no significant differences between MMR-negative and MMR-positive tumors in terms of other clinical and morphological parameters (including the stage of the tumor process). The overall median survival of patients with MMR-negative tumors was 76%, which significantly (p=0.013) exceeds that in the group of MMR-positive tumors (36%). It was found that despite significant differences in survival, MMR-status is not an significant prognostic factor in gastric cancer (HR=0.983). CONCLUSION: The established differences in patient survival make it possible to distinguish a group of MMR-negative tumors into a separate pathogenetic subtype of gastric cancer (MSI subtype) based on immunohistochemical studies. This subtype occurs predominantly in elderly patients with tubular gastric adenocarcinomas and is characterized by a favorable prognosis.

[Ergonomic parameters of the pathologist's workplace as important factors in the prevention of occupational musculoskeletal diseases]. / Ergonomicheskie parametry rabochego mesta vracha-patologoanatoma kak vazhnye faktory profilaktiki professional'nykh zabolevanii oporno-dvigatel'nogo apparata.

BACKGROUND: More than 80% of pathologists suffer from various manifestations of disorders of the musculoskeletal system. The daily duties of pathologists include several hours of work at a microscope and a computer. Microscopes are often not optimized for ergonomics and do not allow the doctor to take the correct sitting position, most often working with a microscope requires leaning forward. OBJECTIVE: To study the ergonomic properties of the workplace of a pathologist and develop specific practical recommendations for long-term work at a microscope. MATERIAL AND METHODS: The study included microscopes with an adjustable and non-adjustable angle of inclination of the tube and height-adjustable chairs. We identify following ergonomic parameters: pathologist height; angle of inclination of the back of the chair; angle of inclination of the microscope tube; angle of inclination of the neck; chair height. The study included 21 participants. Statistical processing and analysis were made using single-factor and multifactorial correlation analysis. RESULTS: A strong positive linear correlation was identified (r=0.80; p<0.05) between the height of test person and angle of inclination of the microscope tube. A strong positive linear correlation was established (r=0.91; p<0.05) between the test person height and the angle of inclination of the neck for microscopes with non-adjustable 31°-angle of inclination of the tube. For microscopes with non-adjustable 45°-angle of inclination of the tube a strong polynomial correlation of the second degree (r=0.85; p<0.05) was found. A moderate negative linear correlation was found between the height of the pathologist and his tilt angle neck with both adjustable and non-adjustable tube angle of the microscope. CONCLUSION: In this study for the first-time exact correlation dependencies between key ergonomic parameters of pathologist's workplace were evaluated. This study showed that only microscopes with an adjustable angle of inclination of the tube allow to achieve an optimal body position.

[Multiplex fluorescent imaging of cancer-associated fibroblasts in colorectal cancer]. / Mul'tipleksnaya flyuorestsentnaya vizualizatsiya opukholeassotsiirovannykh fibroblastov v kolorektal'nom rake.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are a heterogeneous cell population in the tumor stroma and have important prognostic and clinical significance for solid tumors, including colorectal cancer. The identification of CAF presents difficulties due to the lack of a unique diagnostic marker. OBJECTIVE: Detection of CAF by multiplex immunohistochemical staining and assessment of their colocalization. MATERIAL AND METHODS: For multiplex IHC staining specimens of 10 colon adenocarcinomas without neoadjuvant treatment were selected. We used «OPAL 7-COLOR MANUAL IHC KIT¼ (Akoya Biosciences, USA) with five antibodies (FAP, PDGFRß, CD31, POD, PCK) for staining and Mantra 2 Quantitative Pathology Imaging System (Akoya Biosciences, USA) for evaluation of results. RESULTS: CD31 and CAF markers (FAP, PDGFRß, POD) are expressed fundamentally in different cells (p<0.0001) in all areas of the tumor (apical, central, invasive margin). Pairs FAP+PDGFRß in all zones demonstrated significantly higher (p<0.0001) square of tandem staining. It shows that these markers are expressed in the same stromal cells (probably CAF). In pair FAP+POD significant colocalization (p=0.011) was detected only in apical zone. We connect this finding rather with active proliferation of population of young fibroblasts in zones of ulceration and granulations than with CAF. CONCLUSION: We evaluated co-localization of CAF markers (FAP, PDGFRß, POD) and endothelial cells (CD31) in different zones of colorectal carcinomas. We showed colocalization of CAF markers for pairs FAP+PDGFRß in all tumor zones and for pair FAP+POD in apical zone.

[PD-L1 expression in EBV-associated gastric carcinomas]. / Ekspressiya PD-L1 v EBV-assotsiirovannom rake zheludka.

OBJECTIVE: Assessment of the incidence of PD-L1 expression in EBV-associated gastric adenocarcinomas, as well as clarification of the clinical and morphological characteristics and median survival of patients with PD-L1-positive EBV-associated gastric cancer. MATERIAL AND METHODS: Samples of surgical material from 127 patients with stomach cancer were studied. Each sample was stained by in situ hybridization using primers for the Epstein-Barr virus-encoded small RNAs (EBER). Expression of PD-L1 was assessed immunohistochemically (PD-L1 SP263, PD-L1 SP142). The results obtained were compared with the main clinical and morphological characteristics of gastric cancer and median survival of patients. RESULTS: The detection rate of PD-L1 SP263 and PD-L1 SP142 in EBV-associated gastric adenocarcinoma in our sample was 100% and 76.9% respectively, thus, PD-L1 expression (SP263, SP142) is significantly more frequently detected in EBV-associated gastric carcinomas. It was found that patients with positive expression of PD-L1 in EBV-associated gastric carcinomas are younger (mean age 56.3 years for SP263 and 55.6 years for SP142), belonging to male gender. In addition, this group is dominated by proximal localization of tumors, ulcerative form of growth, tubular histological type, intermediate subtype according to P. Lauren. These characteristics do not depend on the antibody clone: positive expression of SP142 and SP 263 was detected in the same patients with a few exceptions. The overall median survival of patients with positive PD-L1 status SP263 in EBV-associated gastric carcinomas was 35 months, for patients with positive PD-L1 status SP142 - 25 months. Median survival of SP142 PD-L1 positive patients is higher than overall median survival of PD-L1 negative patients in EBV-associated gastric carcinomas. It was found that PD-L1 status in EBV-associated gastric cancer is not a significant prognostic factor. CONCLUSION: A single PD-L1 status does not significantly affect the prognosis in patients with gastric cancer, including those in the group of EBV-associated carcinomas, and can only be considered in conjunction with 'classic' clinical and morphological characteristics, primarily with the stage of the tumor process, since they determine the prognostic properties of the tumor.

[Study of gastric adenocarcinomas association with the Epstein-Barr virus-encoded small RNAs]. / Issledovanie assotsiatsii adenokartsinom zheludka s malymi virusnymi RNK virusa Epshteina­Barr.

OBJECTIVE: Assessment of the incidence of EBV-associated gastric adenocarcinomas in a sample of Russian patients, as well as clarification of the clinical and morphological characteristics and median survival of patients with EBV-associated gastric cancer. MATERIAL AND METHODS: We used samples of surgical material from 282 patients with a verified diagnosis of gastric cancer. Each sample was stained by in situ hybridization using primers for the Epstein-Barr virus-encoded small RNAs (EBER). The results obtained were compared with the main clinical and morphological characteristics of gastric cancer. RESULTS: The detection rate of EBV-associated gastric adenocarcinoma in our sample was 9.57%. EBER-positive tumors much more often (p=0.021) belong to the intermediate type according to the P. Lauren classification (66.67%) in comparison with EBER-negative tumors (38.82%). EBER-positive tumors significantly more often (p=0.035) belong to high-grade tumors - 75.00% in comparison with EBER-negative tumors (52.13%). The overall median survival of all patients with EBER-positive tumors (53.5 months) was higher compared to the overall median survival of all patients with EBER-negative tumors - 36.5 months (p=0.5379). The median survival of patients with EBER-positive stage III tumors (30.0 months) was also higher compared to that for patients with EBER-negative tumors - 20.0 months (p=0.5622). It was found that a single EBER status is not a significant prognostic factor (HR=1.0143; CI: 0.9897-1.0196). CONCLUSION: Separately taken EBER-status is not a significant independent prognostic factor and can be considered only in conjunction with the «classical¼ clinical and morphological characteristics, primarily with the stage of the tumor process, since it is they that determine the prognostic properties of the tumor.

Epstein-Barr Virus in the Development of Colorectal Cancer (Review).

The study of the influence of the Epstein-Barr virus (EBV) on the development of colorectal cancer is of current interest, particularly in light of the active discussion of the participation of this virus in the carcinogenesis of stomach cancer. In this review, aimed at a fundamental understanding of the processes associated with the impact of EBV on the human body, attention is paid to the issues of the life cycle of the virus, its phases (latent and lytic), as well as proteins that may be detected in each of the phases. The papers reporting on the role of EBV in the development of colorectal cancer have been analyzed. A summary table indicating the population under study, the number of samples, the method, and the result obtained is provided. Given that the primary cells affected by EBV are lymphocytes, it is logical to assume the involvement of this virus in the development of inflammatory bowel diseases. The review cites studies which confirm the presence of virus DNA in tissues in the inflammatory diseases of the colon, including microscopic and ulcerative colitis. To confirm the direct impact of EBV on the development of colorectal cancer, large studies with applying various methods for detecting the virus and the mandatory description of its localization are required. Besides, it is necessary to correlate these data with the clinical and morphological characteristics of EBV.

[Podoplanin`s expression in cancer-associated fibroblasts close to tumor budding of invasive edge]. / Ekspressiya podoplanina v opukholeassotsiirovannykh fibroblastakh vblizi opukholevykh pochkovanii invazivnogo kraya.

INTRODUCTION: Tumor budding was declared as independent prognostic factor for early cancer in 2016. Tumor-associated fibroblasts (CAFs) are one of the main components of tumor microenvironment. Plenty of different markers are used for detection of CAFs, including podoplanin (POD). OBJECTIVE: The aim of this study is to identify correlation between tumor budding, that indicates tumor invasive potential and is considered to be a negative prognostic factor, and CAFs near tumor buds using POD. MATERIAL AND METHODS: 43 cases of colon adenocarcinoma are included in the study. Double staining immunohistochemical technology with PCK and POD was used for detection of tumor budding and evaluation of POD expression near tumor buds. RESULTS: Significant correlations are revealed between tumor budding and depth of tumor invasion (p=0.023)/regional lymph node metastasis (p=0.068), but between POD expression and depth of tumor invasion (p=0.088) only a tendency of correlation is identified. These facts demonstrate critical prognostic value of tumor budding instead POD expression near tumor buds. It was found that intensity of POD expression near tumor buds is statistically analogous to POD expression in the invasive margin (p=0.0016). That means it is not necessary to evaluate POD expression exactly near tumor buds. For the first time stronger POD expression near mucin complexes is reported. That, probably, will allow to use mucin complexes as alternative prognostic factor instead tumor budding, as tumor buds are absent in mucinous adenocarcinoma.

[E-cadherin expression in tumor emboli in gastric cancer]. / Ekspressiya E-kadgerina v opukholevykh embolakh pri rake zheludka.

OBJECTIVE: To determine the level of E-cadherin expression in tumor emboli, to compare it with expression in a tumor, to determine the dependence of E-cadherin expression in tumor emboli on the clinical and morphological characteristics of gastric cancer. MATERIAL AND METHODS: We used samples of surgical material from 280 patients with a verified diagnosis of gastric cancer. E-cadherin expression was determined by immunohistochemical method. The results of the reactions were assessed semi-quantitatively and compared with the main clinical and morphological characteristics of gastric cancer (histological type according to the WHO classification 2019, histological type according to the classification of P. Lauren, clinical stage, depth of invasion (T), number of metastases in lymph nodes (N), presence or/absence of distant metastases (M), tumor localization in the stomach). RESULTS: Among 280 cases of cancer, emboli were detected only in 67 cases, used for further analysis. The rest of the samples were excluded from the analysis, since emboli did not get into the sections during the cutting of immunohistochemical preparations. The expression of E-cadherin in tumor emboli was significantly higher (p<0.001) than in tumor tissue. At the same time, no cases identified where the level of E-cadherin decreased in emboli compared to the tumor. A significant increase in the expression of E-cadherin in tumor emboli compared to the primary tumor was noted for all histological types according to WHO 2019, for intermediate and diffuse types according to the P. Lauren classification (p<0.001). Comparison of expression in emboli and tumors for neoplasms with different depths of invasion (T), different stages and different localizations did not reveal statistically significant differences. An increase in the expression of E-cadherin in emboli compared to tumors was characterized by a higher level of significance in the presence of metastases (N1, N2, N3a, N3b; p<0.001) than in the absence of metastases (N0; p=0.016). CONCLUSION: The study revealed a statistically significant increase in the expression of E-cadherin in tumor emboli compared to the primary tumor, which is evidence of its important role in maintaining the integrity of emboli and tumor dissemination.

[Persistence of Epstein-Barr virus antigens in gastric cancer: characteristic of inflammatory cellular reactions in tumor]. / Persistentsiya antigenov virusa Epshteina­Barr pri rake zheludka: kharakteristika vospalitel'nykh kletochnykh reaktsii v opukholi.

THE AIM OF THE STUDY: Is to establish the relationship between the persistence of viral antigens of the Epstein-Barr virus (EBV) and the cellular composition of the immune microenvironment of tumor tissue and the mucous membrane of peritumoral area in gastric cancer. MATERIAL AND METHODS: We used samples of surgical material from 55 patients with a verified diagnosis of gastric cancer. The expression of CD4, CD8, CD68, CD1a and LMP-1 was assessed. The results were assessed by the morphometric method. We selected three fields of view (magnification x200) in tumor tissue and in peritumoral areas separately and counted an absolute number of cells with positive staining with further calculation of the average number of cells and the median. RESULTS: LMP-1-negative tumors with LMP-1 expression in epithelium of peritumoral area were characterized by the highest density of CD4+ lymphocyte infiltration in the central part of the tumor; the highest density of CD8+ lymphocyte infiltration in the mucous membrane of peritumoral area (p=0.0190); the highest density of infiltration by macrophages in the mucous membrane of peritumoral area (p=0.2492); the highest density of infiltration by CD1a+ cells in the mucous membrane of peritumoral area (p=0.1503). The highest density of infiltration with CD1a+ cells was characteristic for LMP-1-positive and LMP-1-negative tumors (p=0.0813). The persistence of the LMP-1 viral antigen in the glandular epithelium of the peritumoral area in our sample does not have a statistically significant effect on the prognosis of the disease (RR=1.7718; p=0.0885) but there is a tendency towards a negative predictive value. CONCLUSION: High density of infiltration of glandular epithelium of peritumoral area with the expression of LMP-1 by CD4+ and CD8+ lymphocytes is most likely associated with the activation of the cellular immune response and may be one of the signs of the persistence of viral antigens. It was shown for the first time that the phenomenon of persistence of the LMP-1 viral antigen is characterized by a trend towards negative predictive value for patients with gastric cancer.

[Leptin and leptin receptor evaluation in atherosclerotic plaques in patients with type 2 diabetes mellitus].

BACKGROUND: Diabetes mellitus (DM) is a significant predictor of atherosclerosis, cardiovascular disease, and cardiovascular mortality. It is known that atherosclerosis occurs earlier in patients with diabetes, reducing the duration of their life. Leptin as well as other inflammatory markers can contribute to the progression of atherosclerosis in patients with DM, participate in the development of a local inflammatory reaction. AIM: Determine the cells immunophenotype of atherosclerotic plaques in patients with diabetes. MATERIALS AND METHODS: We analyzed 24 patients (20 men and 4 women), who underwent aortofemoral bypass, femoral-tibial bypass or carotid endarterectomy. During the operation, a fragment of the arterial wall with an atherosclerotic plaque was obtained for further immunohistochemical studies. Five histologic plaque characteristics (CD68+, -SMA, CD34, leptin and leptin receptor) were compared. RESULTS: No difference in the expression of CD68 (p=0.922), -SMA (p=0.192), CD34 (p=0.858), leptin receptor (p=0.741) and leptin (p=0.610) in atherosclerotic plaques were observed between patients with and without DM. The lack of significant differences between the two groups was possibly due to the small number of observations with DM. In particular, when assessing the expression of selected markers in atherosclerotic plaques, patients with DM showed significantly more leptin receptors than patients without DM (2160.716 and 1205.88 respectively); and also significantly less CD68+ (0.39 and 0.98 respectively) and -SMA+ (6.5 and 13.5 respectively). CONCLUSION: Based on the expression of CD68, -SMA, CD34, leptin receptor and leptin, no significant differences were observed in atherosclerotic plaque between patients with and without DM. At the same time, despite the limitations of the study (a small number of patients, moderate severity of DM, elderly patients in the DM group), we found a tendency in the increased number of leptin receptors and a decreased number of -SMA+, CD68+ in DM atherosclerotic plaques. Further study needed, taking into account the limitations of this work.

[Changes in the classification of malignant colon epithelial neoplasms. (WHO, 2019, 5th edition)]. / Novoe v klassifikatsii zlokachestvennykh epitelial'nykh opukholei tolstoi kishki. (VOZ, 2019, 5-e izdanie).

There are not many changes compared to 2010 in WHO classification (2019) of colon adenocarcinomas. Cribriform comedo-type adenocarcinoma (ICD-O code: 8201/3), spindle cell carcinoma (8032/3), squamous cell carcinoma (8070/3) are excluded; carcinoma with a sarcomatoid component (8033/3), poorly cohesive carcinoma (8490/3) and adenoma-like adenocarcinoma (8262/3) were added. The important histological characteristics in the conclusion should indicate the presence of lymphatic invasion, intra- and extramural vascular invasion, perineural invasion, grading, «tumor budding¼ and the immune microenvironment. In the 5th edition of the classification a large section has been added regarding molecular diagnostics and molecular prognostic factors of colorectal cancer. Correspondence was found between two different classifications based on two different approaches: genomic (according to DNA analysis) and transcriptomic (according to RNA analysis). According to the genomic classification two large groups of colorectal cancer are distinguished: hypermutated and non-hypermutated cancers that correspond to molecular pathways with the development of microsatellite and chromosomal instabilities, respectively. The section of neuroendocrine tumors did not undergo significant changes. It is not recommended to use the term «carcinoid¼ to refer to a neuroendocrine tumor G1, that is, the term «carcinoid¼ is excluded.

[Claudin-3 expression in gastric cancer]. / Ékspressiia klaudina-3 v rake zheludka.

Claudins are a family of transmembrane proteins which are essential for the formation and maintenance of epithelial tight junctions. Altered expression of claudins may lead to structural and functional damage of tight junctions, which plays an important role in tumorigenesis and cancer progression. The expression of claudin-3 in gastric cancer is not yet well understood. AIM: To evaluate the expression of claudin-3 in gasric cancer and in adjacent normal mucosa and its association with clinical and pathological parameters. SUBJECT AND METHODS: Tissue specimens from a total of 69 patients with gastric cancer were obtained. Immunohistochemical reactions were performed using mouse polyclonal antibodies to claudin-3. RESULTS: The expression of claudin-3 in gastric cancer was significantly higher than in adjacent normal mucosa (p<0,05). The absence of claudin-3 was significantly associated with poor differentiation (p<0,05). An abnormal nuclear expression of claudin-3 was observed in 69.6% cases. A significant association was found between nuclear expression and the absence of membranous claudin-3 expression (p<0,05).

[A new one in the classification of benign colon epithelial tumors (WHO, 2019, 5th edition)]. / Novoe v klassifikatsii dobrokachestvennykh épitelial'nykh opukholei tolstoi kishki (VOZ, 2019, 5-e izdanie.

The 2019 WHO Classification of Benign Colon Epithelial Neoplasms includes serrated dysplasia, adenomatous polyps, and glandular intraepithelial neoplasia. Serrated dysplasia (ICD-O 8213/0 and 8213/2) is former serrated masses. There is an expected change in its terminology: it is proposed to use the term 'sessile serrated lesion' (SSL) instead of that 'sessile serrated polyp/adenoma' that causes a lot of discussion. The 2019 WHO Classification versus the 2010 WHO classification more clearly defines the TSA criteria: slit-like serration and high elongated cells with pronounced eosinophilic cytoplasm and an elongated pencillate nucleus. The traditional adenomas are renamed in the classification; the term 'adenomatous polyps' that still includes tubular, tubulovillous, and villous adenomas is adopted instead of the term 'adenomas'. The criteria for adenomas remain the same (by the area occupied by villous structures). The 5th edition introduces a separate large section devoted to inflammatory bowel disease-associated dysplasia that is defined as obvious epithelial neoplastic changes that are limited to the basement membrane. The diagnosis can only be used for specific lesions, such as Crohn's colitis and ulcerative colitis.

[Cancer-associated fibroblasts and their significance in tumor progression]. / Opukhol'-assotsiirovannye fibroblasty i ikh znachenie v progressii zlokachestvennykh novoobrazovanii.

Carcinogenesis and tumor progression are not caused not only by malignant epithelial cells, but also by the tumor stroma around cancer stem cells which performs regulatory, nutritional and 'framework' functions. It is represented by mesenchymal cells of various types predominantly by cancer-associated fibroblasts (CAF). αSMA, FAP-1, desmin, podoplanin, neuron-glial antigen 2 (NG2), PDGFR-α and -ß are used for CAF identification but there is no universal markers due to the plasticity of the cell population that underlies the subpopulation division CAF. CAF subpopulations are not described for many tumor types. Recently, evidence has accumulated that CAFs mediate many adverse processes in the tumor, including can support stromal inflammation and cause fibrosis. By forming a niche in cancer stem cells, CAFs mediate chemoresistance and the appearance of dormant metastases. The study of the role of CAF will allow not only to form a fundamentally new understanding of the mechanisms of carcinogenesis, but also to create new diagnostic and therapeutic targets for treating tumors.