Adjuvant radiotherapy for gastric cancer-end of the road?

Hypoxia-based critical gene biomarkers as prognostic reporters for gastric adenocarcinoma

BACKGROUND

Gastric cancer is the most common malignant tumour of the digestive system, yet there is a lack of reported prognostic biomarkers for STAD patients.

METHODS

Transcriptomic expression data of STAD from GEO database, single cell sequencing data from OMIX gastric cancer database. Conservative molecular typing of gastric cancer was constructed using non-negative matrix factorization (NMF). The abundance of 28 immune cells in the tumour samples was assessed using ssGSEA. The R package "oncoPredict" was used to predict chemotherapy response. TIDE website for immunotherapy response prediction. Finally, single cell analysis was performed to clarify the specific type annotation of STAD cells and to analysis their spatial expression.

RESULTS

Hypoxia-score demonstrated excellent prognostic discrimination in TCGA gastric cancer samples. Among multiple deconvolution-based algorithms for immune infiltration, Hypoxia-score presented a general immunosuppressive efficacy across multiple datasets, as evidenced by a broad negative correlation with immune cell infiltration. By the likelihood that each group may have specific drug sensitivity to multiple chemotherapeutic and targeted agents. Results showed that high-risk scoring patients were more sensitive to Staurosporine, Sabutoclax, and AZD8055, while low-risk patients were more sensitive to Bortezomib, Dactinomycin, Docetaxel, Daporinad, Sepantronium, and bromide. In the immunotherapy cohort, the Hypoxia-score presented the ability to discriminate for immunotherapy efficacy. The distribution of Hypoxia-score in single-cell descending space was calculated using AddModuleScore and was found to be distributed across the various cell types annotated in the single-cell analysis. It is suggested that various cells in the tumour microenvironment are involved in hypoxia gene set processes to varying degrees.

CONCLUSION

The Hypoxia-score proves to be a valuable tool for assessing the prognosis of gastric cancer patients and guiding drug treatments, providing significant guidance for clinical diagnosis and treatment in the context of gastric cancer.

Development and validation of nomogram models to predict radiotherapy or chemotherapy benefit in stage III/IV gastric adenocarcinoma with surgery

Objectives

The advanced gastric adenocarcinoma (GAC) patients (stage III/IV) with surgery may have inconsistent prognoses due to different demographic and clinicopathological factors. In this retrospective study, we developed clinical prediction models for estimating the overall survival (OS) and cancer-specific survival (CSS) in advanced GAC patients with surgery.

Methods

A retrospective analysis was conducted using the Surveillance, Epidemiology, and End Results (SEER) database. The total population from 2004 to 2015 was divided into four levels according to age, of which 179 were younger than 45 years old, 695 were 45-59 years old, 1064 were 60-74 years old, and 708 were older than 75 years old. There were 1,712 men and 934 women. Univariate and multivariate Cox regression analyses were performed to identify prognostic factors for OS and CSS. Nomograms were constructed to predict the 1-, 3-, and 5-year OS and CSS. The models' calibration and discrimination efficiency were validated. Discrimination and accuracy were evaluated using the consistency index, area under the receiver operating characteristic curve, and calibration plots; and clinical usefulness was assessed using decision curve analysis. Cross-validation was also conducted to evaluate the accuracy and stability of the models. Prognostic factors identified by Cox regression were analyzed using Kaplan-Meier survival analysis.

Results

A total of 2,646 patients were included in our OS study. Age, primary site, differentiation grade, AJCC 6th_TNM stage, chemotherapy, radiotherapy, and number of regional nodes examined were identified as prognostic factors for OS in advanced GAC patients with surgery (P < 0.05). A total of 2,369 patients were included in our CSS study. Age, primary site, differentiation grade, AJCC 6th_TNM stage, chemotherapy, radiotherapy, and number of regional nodes examined were identified as risk factors for CSS in these patients (P < 0.05). These factors were used to construct the nomogram to predict the 1-, 3-, and 5-year OS and CSS of advanced GAC patients with surgery. The consistency index and area under the receiver operating characteristic curve demonstrated that the models effectively differentiated between events and nonevents. The calibration plots for 1-, 3-, and 5-year OS and CSS probability showed good consistence between the predicted and the actual events. The decision curve analysis indicated that the nomogram had higher clinical predictive value and more significant net gain than AJCC 6th_TNM stage in predicting OS and CSS of advanced GAC patients with surgery. Cross-validation also revealed good accuracy and stability of the models.

Conclusion

The developed predictive models provided available prognostic estimates for advanced GAC patients with surgery. Our findings suggested that both OS and CSS can benefit from chemotherapy or radiotherapy in these patients.

System Analysis Based on Lipid-Metabolism-Related Genes Identifies AGT as a Novel Therapy Target for Gastric Cancer with Neoadjuvant Chemotherapy

Gastric cancer (GC) is one of the most common causes of cancer-related deaths worldwide, and chemotherapy is still a standard strategy for treating patients with advanced GC. Lipid metabolism has been reported to play an important role in the carcinogenesis and development of GC. However, the potential values of lipid-metabolism-related genes (LMRGs) concerning prognostic value and the prediction of chemotherapy responsiveness in GC remains unclear. A total of 714 stomach adenocarcinoma patients were enrolled from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. Using univariate Cox and LASSO regression analyses, we developed a risk signature based on LMRGs that can distinguish high-GC-risk patients from low-risk patients with significant differences in overall survival. We further validated this signature prognostic value using the GEO database. The R package “pRRophetic” was applied to calculate the sensitivity of each sample from high- and low-risk groups to chemotherapy drugs. The expression of two LMRGs, AGT and ENPP7, can predict the prognosis and response to chemotherapy in GC. Furthermore, AGT significantly promoted GC growth and migration, and the downregulation of AGT enhanced the chemotherapy response of GC both in vitro and in vivo. Mechanistically, AGT induced significant levels of epithelial–mesenchymal transition (EMT) through the PI3K/AKT pathway. The PI3K/AKT pathway agonist 740 Y-P can restore the EMT of GC cells impaired by AGT knockdown and treatment with 5-fluorouracil. Our findings suggest that AGT plays a key role in the development of GC, and targeting AGT may help to improve the chemotherapy response of GC patients.

Overview of Chemotherapy for Gastric Cancer

Gastric cancer (GC) is one of the most clinically challenging cancers worldwide. Over the past few years, new molecular-targeted agents and immunotherapy have markedly improved GC prognosis. Human epidermal growth factor receptor 2 (HER2) expression is a key biomarker in first-line chemotherapy for unresectable advanced GC. Further, the addition of trastuzumab to cytotoxic chemotherapy has extended the overall survival of patients with HER2-positive advanced GC. In HER2-negative GC, the combination of nivolumab, an immune checkpoint inhibitor, and a cytotoxic agent has been demonstrated to prolong the overall survival of GC patients. Ramucirumab and trifluridine/tipiracil, which are second- and third-line treatments for GC, and trastuzumab deruxtecan, an antibody-drug conjugate for HER2-positive GC, have been introduced in clinics. New promising molecular-targeted agents are also being developed, and combination therapy comprising immunotherapy and molecular-targeted agents is expected. As the number of available drugs increases, it is important to understand the target biomarkers and drug characteristics and select the optimal therapy for each patient. For resectable disease, differences in the extent of standard lymphadenectomy between Eastern and Western countries have led to different standard treatments: perioperative (neoadjuvant) and adjuvant therapy. This review aimed to summarize recent advances in chemotherapy for advanced GC.

Is there still a place for radiotherapy in gastric cancer?

Stomach cancer is an aggressive disease and represents a global health problem. The majority of patients with localised disease present with locally advanced cancer that requires multimodality treatment. Chemoradiotherapy delivered after D2 gastrectomy has been evaluated in a number of clinical studies and best evidence, thus far, does not support its use in the post-operative setting. Data from currently recruiting and ongoing trials with exploratory translational endpoints are eagerly awaited to direct the use of chemoradiotherapy in the neoadjuvant setting. Radiotherapy can be effective in the palliation of symptoms associated with advanced gastric cancer. Furthermore, Stereotactic Body Radiotherapy has the potential to provide long term disease control in a proportion of gastric cancer patients with oligometastatic liver disease.

Radiosensitizing effects of pyrogallol-loaded mesoporous or-ganosilica nanoparticles on gastric cancer by amplified ferroptosis

Radiotherapy (RT) incorporated multidisciplinary treatment is producing excellent clinical results, but its efficacy in treating late-stage gastric cancer is constrained by radioresistance and RT-related toxicity. Especially, since reactive oxygen species are the pivotal effectual molecules of ionizing radiation, improving ROS production by nanoparticles and other pharmacological modulation to amplify oxidation of polyunsaturated fatty acids and subsequent ferroptotic cell death is shown to enhance cancer cell radioresponse. Herein, we constructed a nanosystem by loading Pyrogallol (PG), a polyphenol compound and ROS generator, into mesoporous organosilica nanoparticles named as MON@pG. The nanoparticles exhibit proper size distribution with amplified ROS production and substantial glutathione depletion under X-ray radiation in gastric cancer cell line. Meanwhile, MON@PG enhanced radiosensitivity of gastric cancer in xenograft tumor model by ROS-mediated accumulation of DNA damage and apoptosis. Furthermore, this augmented oxidative process induced mitochondrial dysfunction and ferroptosis. In summary, MON@PG nanoparticles show the capacity to improve RT potency in gastric cancer by disrupting redox balance and augmenting ferroptosis.

The Regulatory Network of Gastric Cancer Pathogenesis and Its Potential Therapeutic Active Ingredients of Traditional Chinese Medicine Based on Bioinformatics, Molecular Docking, and Molecular Dynamics Simulation

Objective. This study aims to investigate the functional gene network in gastric carcinogenesis by using bioinformatics; besides, the diagnostic utility of key genes and potential active ingredients of traditional Chinese medicine (TCM) for treatment in gastric cancer have been explored. Methods. The Cancer Genome Atlas and Gene Expression Omnibus databases have been applied to analyze the differentially expressed genes (DEGs) between gastric cancer and normal gastric tissues. Then, the DEGs underwent Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses using the Metascape database. The STRING database and the Cytoscape software were utilized for the protein-protein interaction network of DEGs and hub genes screening. Furthermore, survival and expression analyses of hub genes were conducted using Gene Expression Profiling Interactive Analysis and Human Protein Atlas databases. By using the Comparative Toxicogenomics Database, the hub genes interconnected with active ingredients of TCM were analyzed to provide potential information for the treatment of gastric cancer. After the molecular docking of the active ingredients of TCM to specific hub gene receptor proteins, the molecular dynamics simulation GROMACS was applied to validate the conformation of the strongest binding ability in the molecular docking. Results. A total of 291 significant DEGs were found, from which 12 hub genes were screened out. Among these hub genes, the expressions of five hub genes including COL1A1, COL5A2, MMP12, SERPINE1, and VCAN were significantly correlated with the overall survival. Furthermore, four potential therapeutic active ingredients of TCM were acquired, including quercetin, resveratrol, emodin, and schizandrin B. In addition, the molecular docking results exhibited that the active ingredients of TCM formed stable binding with the hub gene targets. SERPINE1 (3UT3)-Emodin and COL1A1 (7DV6)-Quercetin were subjected to molecular dynamics simulations as conformations of continuing research significance, and both were found to be stably bound as a result of the interaction of van der Waals potentials, electrostatic, and hydrogen bonding. Conclusion. Our findings may provide novel insights and references for the screening of biomarkers, the prognostic evaluation, and the identification of potential active ingredients of TCM for gastric cancer treatment.

The correlation of serum sirt6 with clinical outcome and prognosis in patients with gastric cancer

BACKGROUND

We aimed to evaluate the correlation between serum sirtuin 6 (sirt6) level and clinicopathological characteristics and prognosis of gastric cancer (GC) patients.

METHODS

The serum sirt6 levels of subjects (135 cases of GC, 68 cases of atrophic gastritis, 60 cases of healthy controls) were analyzed by enzyme-linked immunosorbent assay. The predictive and prognostic values of sirt6 serum level for GC were determined by performing receiver operating characteristic curve (ROC), Kaplan-Meier analysis, as well as univariate and multivariate Cox regression, respectively.

RESULTS

GC patients showed lower sirt6 serum levels than that of atrophic gastritis patients and healthy control. Taking the healthy control as a reference, the area under the ROC curve (AUC) of sirt6 serum level for diagnosing GC was 0.955 with a sensitivity of 91.85% and a specificity of 90.0%. Based on ROC analysis using atrophic gastritis as the state variable, serum sirt6 had a high diagnostic efficiency for GC (AUC = 0.754). Serum sirt6 was related to the clinicopathological features (tumor size, Lauren's classification, tumor node metastasis staging, lymph node metastasis) and overall survival (log-rank χ2 = 12.22, P < .001). The AUC of serum sirt6 predicting death in GC patients was 0.731. At the optimal cutoff value (16.83 ng/mL), the sensitivity and specificity of sirt6 were 59.57% and 79.55%, respectively. Moreover, lower sirt6 level as independent risk factor was revealed to affect prognosis of GC patients (P = .018).

CONCLUSION

Serum sirt6 level was positively associated with the tumor stage and metastasis conditions, which could be served as diagnostic and predictive biomarkers in GC.

Modification of erythrocytes by internalizing Arg-Gly-Asp (iRGD) in boosting the curative effect of radiotherapy for gastric carcinoma

BACKGROUND

Radiation resistance remains the leading cause of radiotherapy (RT) failure. The development of tumor-specific targeted sensitizers is key to overcoming radiation resistance. Our early data showed that cancer cell penetration was simulated by internalizing arginine-glycine-aspartic acid (iRGD), and the irradiation efficacy was improved. The present study aims to design and fabricate iRGD-modified red blood cell (RBCs) for tumor targeting and RT enhancement, and to evaluate its safety and efficacy in vivo.

METHODS

1,2-Distearoyl-sn-glycero-3-phosphoethanolamine-poly ethylene glycol-iRGD (DSPE-PEG-iRGD) was used to modify RBCs by a lipid-insertion method without direct chemical bioconjugation. Fluorescent dyes were used to trace the functional RBCs through confocal microscopy examination. In vitro stability evaluation was performed using cell culture medium incubation for 48 h followed by fluorescence decay assay. Furthermore, a subcutaneous cancer cell mouse model was constructed with MKN-45 cells for target efficacy and RT enhancement evaluation with DSPE-PEG-iRGD-modified RBCs (RBC-iRGD).

RESULTS

Successful construction of RBC-iRGD was verified by the presence of the yellow fluorescence, and an approximately 10⁸ iRGD molecules were labeled on a single RBC. The final RBC-iRGD showed good stability without any hemolytic effects in the cell culture medium. Moreover, higher fluorescence intensity and decreased liver and spleen accumulation could be observed in RBC-iRGD compared to RBC + iRGD in vivo. The RBC-iRGD exerted enhanced radiosensitivity in subcutaneous gastric tumor mice.

CONCLUSIONS

The RBC-iRGD exerted good tumor-targeting efficacy and favorable effects for RT enhancement in vivo.

Neoadjuvant Chemoradiotherapy for Locally Advanced Gastric Cancer: Where Are We at?

Simple Summary

More than 50% of gastric cancer are at least locally advanced at presentation. For such patients, a multimodal approach rather than mere surgical resection leads to better long-term prognosis. Neoadjuvant chemoradiotherapy is one of the common treatment strategies for local advanced gastric cancer. Based on the experience and evidence from esophago-gastric cancers, the incorporation of systemic and locoregional therapy has shown superior disease control and reduced local recurrence. However, the optimal chemotherapy regimen, patient selection, technical consideration and potential biomarkers are still under investigation. Furthermore, the comparison of neoadjuvant chemoradiotherapy with neoadjuvant/perioperative chemotherapy is also an important issue to be answered. In the review article, we addressed the current available evidence to provide a comprehensive understanding and the use of neoadjuvant chemoradiotherapy for locally advanced gastric cancer. Future studies and ongoing trials will be necessary to determine the best candidate and the role of newer systemic and radiation therapies in such patients. NCRT is a feasible treatment option for LAGC, with the ability to achieve favorable disease control and enable higher radical resection rates over those afforded by perioperative chemotherapy or surgery alone. Large clinical trials examining the comparative efficacy of NCRT and NCT are underway. The discrepancy between the satisfactory pCR rates associated with NCRT and the nonsignificant association between NCRT and survival warrants further exploration. Furthermore, newer therapies such as immunotherapy and adaptive radiotherapy may be implemented in con-junction with NCRT, and the development of useful biomarkers may ultimately lead to the de-velopment of personalized treatments for LAGC. These research directions may lead to the dis-covery of the optimal approach to administering NCRT to patients with LAGC. They may also aid in the determination of the optimal candidates for undergoing NCRT.

Abstract

Locally advanced gastric cancer (LAGC) has a poor prognosis with surgical resection alone, and neoadjuvant treatment has been recommended to improve surgical and oncological outcomes. Although neoadjuvant chemotherapy has been established to be effective for LAGC, the role of neoadjuvant chemoradiotherapy (NCRT) remains under investigation. Clinical experience and research evidence on esophagogastric junction adenocarcinoma (e.g., cardia gastric cancers) indicate that the likelihood of achieving sustainable local control is higher through NCRT than through resection alone. Furthermore, NCRT also has an acceptable treatment-related toxicity and adverse event profile. In particular, it increases the likelihood of achieving an R0 resection and a pathological complete response (pCR). Moreover, NCRT results in higher overall and recurrence-free survival rates than surgery alone; however, evidence on the survival benefits of NCRT versus neoadjuvant chemotherapy (NCT) remains conflicting. For noncardia gastric cancer, the efficacy of NCRT has mostly been reported in retrospective studies, and several large clinical trials are ongoing. Consequently, NCRT might play a more essential role in unresectable LAGC, for which NCT alone may not be adequate to attain disease control. The continual improvements in systemic treatments, radiotherapy techniques, and emerging biomarkers can also lead to improved personalized therapy for NCRT. To elucidate the contributions of NCRT to gastric cancer treatment in the future, the efficacy, potential toxicity, predictive biomarkers, and clinical considerations for implementing NCRT in different types of LAGC were reviewed.

Systemic therapy for gastric cancer: Perioperative strategies and beyond

Each year, gastric cancer claims the lives of hundreds of thousands of patients worldwide. Despite surgical resection, the risk of residual disease, micrometastatic disease, and disease recurrence remain elevated. Herein, we review systemic therapy strategies in the neoadjuvant, adjuvant, and metastatic settings, including novel uses of immunotherapy, targeted therapies and cytotoxic chemotherapies, for the treatment of gastric cancer.

Union is strength: Textbook outcome with perioperative chemotherapy compliance decreases the risk of death in advanced gastric cancer patients

PURPOSE

Perioperative chemotherapy (POC) in advanced gastric cancer (GC) patients significantly increases the curative resection rate and overall survival (OS). Textbook outcome (TO) represents a composite of surgical quality metrics strongly associated with improved OS. However, the current definition of TO after resection for GC does not include POC. Herein we propose to supplement the current description of TO with an additional feature, POC compliance. The present study aimed to evaluate prognostic impact of thus defined textbook oncological outcome (TOO) among patients undergoing gastrectomy for advanced GC.

PATIENTS AND METHODS

We collected data from a prospectively maintained database of all patients operated for GC between 2010 and 2020 in our institution. Patients with histologically confirmed and resectable advanced GC but without distant metastases, in whom multimodal treatment was planned by institutional MDT were included.

RESULTS

A total of 194 patients were analyzed. In the multivariate analysis, patients with TOO had a 50 % lower risk of death than patients without TOO (medians: NR vs 42 months; HR = 0.50, p = 0.0109). Patients treated with POC had a 43 % lower risk of death than patients treated with only preoperative chemotherapy (medians: 78 vs 33 months; HR = 0.57, p = 0.0450). Patients with a pathological response (PR) in the primary tumor had a 59 % lower risk of death than patients without PR (medians: NR vs 36 months; HR = 0.41, p = 0.0229). POC combined with TO surgery significantly decreased the risk of death in advanced GC patients (medians: NR vs 42 months; HR = 0.35, p = 0.0258).

CONCLUSION

Since TOO is associated with improved survival, it may serve as a multimodal treatment quality parameter in patients with advanced GC.

[Neoadjuvant and perioperative treatment of gastric cancer, current studies and new biomarkers]

According to current German and European clinical practice guidelines perioperative chemotherapy is the recommended standard of care for localized gastric cancer beyond early cancers, i.e. in stage IB (T2 N0 M0 and T1 N1 M0) or greater. For patients who are able to tolerate intensive chemotherapy, the FLOT regimen (5-fluorouracil, folinic acid, oxaliplatin, docetaxel) should be administered preoperatively and postoperatively for four cycles each. Locally advanced nonmetastatic adenocarcinoma of the esophagogastric junction (AEG) should be treated with perioperative chemotherapy as for gastric cancer or alternatively with neoadjuvant chemoradiotherapy. The best approach for AEG is currently being investigated in ongoing clinical trials. The recommendation of perioperative treatment applies to all histopathological subtypes of gastric cancer. The article summarizes the contemporary data and provides an outlook on current progress in the field of medicinal perioperative treatment.