Expression of LGR5, FZD7, TROY, and MIST1 in Perioperatively Treated Gastric Carcinomas and Correlation with Therapy Response

Wnt signaling in gastric cancer: current progress and future prospects

Levels of the Wnt pathway components are abnormally altered in gastric cancer cells, leading to malignant cell proliferation, invasion and metastasis, poor prognosis and chemoresistance. Therefore, it is important to understand the mechanism of Wnt signaling pathway in gastric cancer. We systematically reviewed the molecular mechanisms of the Wnt pathway in gastric cancer development; and summarize the progression and the challenges of research on molecular agents of the Wnt pathway.

Clinical Implications and Prognostic Value of Leucine-Rich G Protein-Coupled Receptor 5 Expression as A Cancer Stem Cell Marker in Malignancies: A Systematic Review and Meta-Analysis

Leucine-rich G protein-coupled receptor 5 (LGR5) is a marker of cancer stem cells (CSCs) in various cancers. Based on different studies, conflicting reports exist on correlation between LGR5 expression and poor prognosis/ clinicopathological parameters in cancer patients. Therefore, our purpose in conducting this study was to investigate correlation between LGR5 expression and outcomes of cancer patients under study through a systematic review and meta-analysis. Relevant articles were searched and collected using EMBASE, PubMed, Science Direct, and Scopus databases until December 21, 2022. This study was conducted to examine correlation between LGR5 expression and different clinical outcomes, such as recurrence-free survival (RFS), disease-free survival (DFS), overall survival (OS), and clinicopathological characteristics of the included cancer patients. To achieve this, hazard ratios (HRs) with 95% confidence intervals (CIs) and odds ratios (ORs) with 95% CIs were used as statistical measures. A meta-analysis was conducted using STATA 12.0 software. Finally, 53 studies including 9523 patients met the inclusion criteria. Significantly, high-level expression of LGR5 was related to poor prognosis in terms of OS, higher tumor stage, presence of distant metastasis, and presence of lymph node metastasis. It was discovered through subgroup analysis that several factors, including the study area, evaluation method, and type of cancer, can influence the correlation between LGR5 expression and negative prognosis in cancer patients. According to the results of our study, LGR5 overexpression was related to poor OS in cancer patients. In addition, clinicopathological data indicated an unfavorable prognosis in cancer patients with high LGR5 expression. In conclusion, LGR5 may serve as a potential prognostic marker for predicting survival in certain cancer types.

Pre-therapeutic molecular biomarkers of pathological response to neoadjuvant chemotherapy in gastric and esophago-gastric junction adenocarcinoma: A systematic review and meta-analysis

PURPOSE

Multimodal treatment is the standard of care in patients with locally advanced gastric cancer. Unfortunately, the response rate after neoadjuvant treatment remains limited. The ability to predict the response has a potential to improve patient outcomes by promoting a more individualized approach. We sought to describe the current state of research in pre-treatment molecular biomarkers of response to neoadjuvant therapy in gastric adenocarcinoma available for testing before the initiation of treatment and to perform a systematic review and meta-analysis in order to summarize and evaluate the potential methods.

METHODS

A systematic MEDLINE, EMBASE and CENTRAL literature search was conducted to extract articles on potentially predictive molecular biomarkers of pathological response to neoadjuvant therapy in patients with gastric- and esophago-gastric junction adenocarcinoma. Fixed and random effects models were used to undertake the meta-analysis when appropriate.

RESULTS

Data on predictive biomarkers was reported in 38 studies. These articles described 47 biomarkers showing statistical significance. After evaluation of all reported biomarkers, 3 of them met the inclusion criteria for meta-analysis. The meta-analysis results indicate that >5 ​ng/mL pre-therapeutic serum concentration of carcinoembryonic antigen (CEA; norm <5 ​ng/mL) is significantly associated with tumor response (RR ​= ​5.13, 95% CI 2.53-10.43, P ​= ​0.026).

CONCLUSION

Previous studies describe a large number of candidate biomarkers. Our meta-analysis indicated pre-therapeutic serum concentration of CEA >5 ​ng/mL as a potential and easy-accessible biomarker available for use before initiation of treatment. However, it could be only an additional tool for complex qualification for neoadjuvant therapy.

Impact of Cancer Stem Cells on Therapy Resistance in Gastric Cancer

Gastric cancer (GC) is the fourth leading cause of cancer death worldwide, with an average 5-year survival rate of 32%, being of 6% for patients presenting distant metastasis. Despite the advances made in the treatment of GC, chemoresistance phenomena arise and promote recurrence, dissemination and dismal prognosis. In this context, gastric cancer stem cells (gCSCs), a small subset of cancer cells that exhibit unique characteristics, are decisive in therapy failure. gCSCs develop different protective mechanisms, such as the maintenance in a quiescent state as well as enhanced detoxification procedures and drug efflux activity, that make them insusceptible to current treatments. This, together with their self-renewal capacity and differentiation ability, represents major obstacles for the eradication of this disease. Different gCSC regulators have been described and used to isolate and characterize these cell populations. However, at the moment, no therapeutic strategy has achieved the effective targeting of gCSCs. This review will focus on the properties of cancer stem cells in the context of therapy resistance and will summarize current knowledge regarding the impact of the gCSC regulators that have been associated with GC chemoradioresistance.

Role of Frizzled receptor expression on patients' survival with gastrointestinal cancers: A systematic review with meta-analysis

BACKGROUND

Frizzled receptors (FZD) play a pivotal role in the initiation and progression of a wide array of cancers. Dysregulated expression of FZD receptors is correlated with higher metastasis and invasive potential, as well as short survival in many malignancies. In this meta-analysis, we aimed to verify the prognostic value of FZD receptor expression on patients' survival with different types of gastrointestinal (GI) cancers, including gastric, colorectal, and esophageal cancers.

METHODS

A systematic search was performed using PubMed, Scopus, and Web of Science from 2000 to November 2020. Fourteen studies, including 2997 patients met our inclusion criteria, in which nine articles were considered FZD7 while the rest were about other FZD members. The fixed-effect model was used to estimate the pooled hazard ratio (HR) and the 5-year overall survival (OS) rate. We used the Newcastle-Ottawa scale of cohort articles to determine the quality of included studies.

RESULTS

The results showed that high expression of FZD receptors is associated with the poor survival in patients with GI cancers (HR= 1.83, 95% CI: 1.5-2.17). Moreover, multivariate analysis indicated that FZD receptors could be considered as an independent prognostic factor (HR = 1.76, 95% CI: 1.37-2.16).

CONCLUSION

According to our results, overexpression of FZD receptors predicts a poor prognosis in patients with GI cancers and could be used as a useful therapeutic target.