Marina V. Zavyalova

Background: Preventing metastasis is important for improving the survival rates of patients with non-small-cell lung cancer (NSCLC). Our previous investigation suggested that premalignant epithelial changes in small bronchi distant from the primary tumor serve as predictive markers of NSCLC metastasis. Specifically, isolated basal cell hyperplasia (iBCH) is associated with a high risk of distant metastasis, whereas basal cell hyperplasia combined with squamous metaplasia (BCH + SM) correlates with a low risk of distant metastasis. Methods: This exploratory study included patients enrolled both retrospectively and prospectively. A total of 83 NSCLC patients were stratified into two groups: iBCH (high metastatic risk, n = 59, including 37 metastatic events) and BCH + SM (low metastatic risk, n = 24, including 6 metastatic events). Paired peripheral blood and tumor samples from NSCLC patients with iBCH and BCH + SM were subjected to whole exome sequencing. Bioinformatic analysis included tumor mutation quantification, detection of regions with enriched mutations, mutational signatures profiling, and evaluation of metastasis-free survival and hazard ratio modeling. Results: Patients with iBCH were characterized by a higher prevalence of single nucleotide variants and a lower frequency of frameshift mutations. Single-nucleotide indels (mainly insertions) were more frequent in patients with BCH + SM. Additionally, ID1, ID3, ID11, and ID13 mutational signatures were significantly enriched in patients with BCH + SM. Moreover, the combination of SBS3, SBS4, DBS1, DBS2, DBS6, ID8, and ID23 signatures was linked to distant metastasis in NSCLC patients. Finally, a multivariable logistic regression model for assessing the probability of distant metastasis in NSCLC was developed based on the histological subtype, the bronchial lesion, and mutational signature. Conclusions: NSCLC with high and low risk of distant metastasis defined by bronchial lesions have specific mutational landscapes.

Aim. To study the co-expression patterns of molecular biological subtype (MBS) markers on individual circulating tumor cells (CTCs) in luminal subtypes of breast cancer (BC) and their association with the expression of stemness and epithelial – mesenchymal transition (EMT) markers. Materials and methods. The study analyzed venous blood and primary tumor biopsies from 51 BC patients (N1– 4N0–3M0), including 21 cases with luminal A, 19 cases with luminal B (HER2–), and 11 cases with luminal B (HER2+) MBS. Flow cytometry was used to assess the expression of CD45, EpCAM, N-/E-cadherin, CD44, CD24, CD133, Her2neu, ER, PR, and Ki67 in CTCs before therapy initiation. Statistical analysis was performed using Statistica 10.0 ( p < 0.05). Results. In luminal A and B (HER2–) primary tumor MBS, phenotypic conversion of CTCs was observed, characterized by the emergence of HER2+ CTCs, which were often ER-negative and exhibited various coexpression patterns of stemness markers. The key practical finding was the identification of a metastasis-associated CTC phenotype in luminal HER2– MBS: CD45–EpCAM+ER–PR–Her2neu+Ki67–. This phenotype corresponds to the classical HER2+ subtype at the level of a single cell. Conclusion. The study results support the feasibility of determining MBS marker expression on a single CTC for predicting the risk of hematogenous metastasis in luminal A and B (HER2–) primary tumor MBS and for optimizing treatment strategies.

Lymphangitic carcinomatosis is one of the most severe forms of tumor progression. It is characterized by the massive spread of tumor emboli, composed of cells with reduced adhesive capacity to the endothelium, through the lymphatic vessels. Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta­Analyses) guidelines, 394 scientific papers were screened. Of those, 292 English-language publications met the criteria for analysis. A total of 39 articles (including three in Russian) relevant to the topic of this review were included. Due to the highly diverse localization of lymphangitic carcinomatosis and its polymorphic symptoms, diagnosis remains challenging and is associated with the risk of erroneous and often delayed decision-making. Data on lymphangitic carcinomatosis are still scarce, and its developmental mechanisms are not fully understood. However, systematizing knowledge about its possible clinical and morphological manifestations and studying the molecular and genetic mechanisms of its development could serve as a basis for identifying key prognostic markers and developing targeted therapies for this currently prognostically unfavorable form of tumor progression.

Objective: to study the expression of alpha-6/beta-4 integrin and laminin-332 in lymph node-positive luminal a breast cancer. Material and Methods. Surgical specimens from 110 patients with luminal a breast cancer (T1–2N0–3M0), who were treated at Tomsk Cancer Research Institute from 2016 to 2022, were analyzed. All patients were divided into two groups: those without lymph node metastases (n=81) and those with lymph node metastases (n=29). The immunohistochemical study was performed according to a standard procedure using antibodies to integrin alpha-6 subunit (ITGA6), integrin beta-4 subunit (ITGB4) and gamma-2 subunit of laminin-332 (LAMG2). Histological samples were digitized using whole-slide scanners. The scanned slices were analyzed using SlideViver V2.8 and QuantCenter software tools. Results. The positive expression of ITGB4 (66 % and 19 %; χ2=22.088; pConclusion. The expression of alpha-6/beta-4 integrin and laminin-332 correlates with lymph node metastasis, and the expression of gamma-2 subunit of lamnin-332 can serve as a marker for lymph node metastasis.

Despite advances in modern oncology, in Russia, 36% of gastric cancers are detected at an advanced stage, with a one-year mortality rate of 39.6%. One of the most common causes of death from gastric cancer is peritoneal carcinomatosis. Synchronous peritoneal carcinomatosis is diagnosed in 18–26% of cases. Metachronous carcinomatosis occurs in 7–39% of patients 8.5–26 months after the primary tumor is removed. To date, there are no effective treatments for peritoneal carcinomatosis. Tumors accompanied by peritoneal carcinomatosis are often resistant to systemic chemotherapy. Cytoreductive surgeries and intraperitoneal chemotherapy are not always possible or successful for all patients.This review focuses on analyzing the molecular and genetic mechanisms of peritoneal carcinomatosis in gastric cancer and presents an original hypothesis suggesting that peritoneal carcinomatosis occurs when tumor cells acquire the ability to autonomously exist in a matrix-independent state in the ascitic fluid without undergoing apoptosis (anoeucsis). Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, 10,025 scientific papers were identified, of which 228 English-language and 323 Russian-language publications met the analysis criteria. Twenty-nine articles (including four Russian-language ones) relevant to the topic of this review were included in the review. It is assumed that the identification of key molecules associated with the matrixindependent existence of tumor cells could serve as the basis for the development of technologies for predicting peritoneal carcinomatosis, as well as for the development of new targeted therapy for metastatic gastric cancer.

Laminins are a family of high-molecular-weight heterotrimeric glycoproteins of the extracellular matrix that play a key structural role in basement membranes. Although mutations in intracellular proteins remain the primary drivers of carcinogenesis, the role of changes in the expression and spatial distribution of laminins in the development of malignant neoplasms is gaining increasing importance. Primary focus is given to the patterns of laminin alterations in carcinomas of various localizations, as well as their role in the acquisition of invasive and metastatic potential by tumor cells. Furthermore, the prognostic significance of different laminin isoforms is discussed.

Objective. To identify in situ stages of entosis in non-small cell lung cancer (NSCLC) tissue and to assess the impact of neoadjuvant chemotherapy (NACT) on their frequency. Material and methods. The study included 9 patients with morphologically verified NSCLC (stage T1—2N0—1M0—1) classified according to the WHO classification (2021). Four patients received NACT (vinorelbine + carboplatin), while five underwent surgery without prior therapy. Histological specimens were examined using Whole Slide Imaging (Pannoramic Mirax Midi, Carl Zeiss, Germany) and analyzed with Panoramic Viewer software. Entotic events were identified according to Mackay’s criteria. Statistical analysis was performed using the Mann—Whitney U test. Results. All five lysosomal stages of entosis were successfully identified in situ. Stage II was the most frequently observed. In patients treated with NACT, Stage III was more common, suggesting a slowing of this phase, while the frequency of Stage V was significantly lower (p=0.01). A trend toward an overall increase in entotic events after NACT was noted; however, when normalized to tumor section area, no significant differences between groups were detected. For the first time in situ, variants of entomammoptosis were identified, including binucleated “loser” cells and mitosis of the internalized cell. Conclusion. Neoadjuvant chemotherapy does not increase the overall frequency of entosis in NSCLC tissue but alters the distribution of stages, prolonging Stage III and reducing the completion of the process at Stage V. The results expand current understanding of the role of entosis in tumor cell adaptation and the development of drug resistance in NSCLC.

Aim. To study the proliferative activity of non-small cell lung cancer with tumor spread through air spaces. Materials and methods. The study included 88 patients with stage IA-IIIA non-small cell lung cancer. The operative material was evaluated. Histologic and immunohistochemical examination was performed according to the standard technique. Antibodies to Ki67 (clone SP6, Cell Marque) were used. On digitized preparations using automated system Pannoramic MIDI with software Slide Viver V2.8. and multi-module platform Quant Center (3D HISTECH, Hungary) we counted the percentage of cells with positive nuclear expression of Ki67 in the tumor as a whole and in the area of spreading. Statistical processing was performed using the STATISTICA 10.0 software package. Differences at p < 0.05 were considered statistically significant. Results. The percentage of Ki67 expression in the tissue of the primary tumor node was higher in cases with the presence of tumor spread through air spaces, including stage IA lung adenocarcinoma. The percentage of Ki67 expression in the area of air space spread of the tumor was higher compared to the percentage of expression in the tumor as a whole. Higher proliferative activity in the zone of tumor air space spread was observed in cases with extensive spread compared to cases with a limited variant of air space spread. Conclusion. The results obtained complement the existing data on the mechanisms of tumor spread through air spaces as a form of invasive growth and one of the variants of tumor progression characteristic of lung cancer.

The review provides a basic description of extracellular matrix proteins and their corresponding receptors expressed by tumor cells that are involved in key mechanisms of metastasis. According to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, 479 of the initially identified 8,112 publications met the inclusion criteria (212 in English and 267 in Russian). The final analysis included 38 articles relevant to the topic of this review, three of which were in Russian. The presented data expand the fundamental knowledge about the molecular mechanisms of metastasis and can be used as a basis for the development of targeted anticancer compounds.

Distant metastasis is the leading cause of death from breast cancer. Тhe mechanism of metastasis may be associated with aberrant expression of αv and β3 integrin subunits in primary tumor cells. Purpose of the study : to evaluate the presence and localization of the expression of αv and β3 integrin subunits in primary breast cancer cells. Material and Methods . Тhe study included 49 women with Т1–4N0–3M0 invasive ductal breast carcinoma. Тhe median age of the patients was 50 years (range: 43 to 60 years). Biopsy samples of the primary tumor were examined. Тhe expression of estrogen and progesterone receptors, c-erB-2 (Her2/ neu), Ki67, CD51 (integrin αV), CD61 (integrin β3) were assessed using immunohistochemistry. Results. Тhe expression of αV integrin (CD51) and β3 integrin (CD61) was studied in relation to key clinical parameters. Тhe Т4 criterion and the presence of regional lymph node metastasis were associated with the expression of αV integrin in the cytoplasm of primary tumor cells. Тhe N3 criterion was associated with the presence of the expression of β3 integrin in the cytoplasm of primary tumor cells. Тhe frequency of positive cytoplasmic expression of β3 integrin subunit was approximately the same in cases with and without hematogenous metastases. Conclusion. Тhe Т4 criterion and the presence of regional lymph node metastasis are associated with the expression of αV integrin subunit in the cytoplasm of primary tumor cells. Тhe N3 criterion is associated with the expression of β3 integrin subunit in the cytoplasm of primary tumor cells.