The impact of preoperative ASA-physical status on postoperative complications and long-term survival outcomes in gastric cancer patients

Construction of an immune-related gene signature for overall survival prediction and immune infiltration in gastric cancer

BACKGROUND

Treatment options for patients with gastric cancer (GC) continue to improve, but the overall prognosis is poor. The use of PD-1 inhibitors has also brought benefits to patients with advanced GC and has gradually become the new standard treatment option at present, and there is an urgent need to identify valuable biomarkers to classify patients with different characteristics into subgroups.

AIM

To determined the effects of differentially expressed immune-related genes (DEIRGs) on the development, prognosis, tumor microenvironment (TME), and treatment response among GC patients with the expectation of providing new biomarkers for personalized treatment of GC populations.

METHODS

Gene expression data and clinical pathologic information were downloaded from The Cancer Genome Atlas (TCGA), and immune-related genes (IRGs) were searched from ImmPort. DEIRGs were extracted from the intersection of the differentially-expressed genes (DEGs) and IRGs lists. The enrichment pathways of key genes were obtained by analyzing the Kyoto Encyclopedia of Genes and Genomes (KEGGs) and Gene Ontology (GO) databases. To identify genes associated with prognosis, a tumor risk score model based on DEIRGs was constructed using Least Absolute Shrinkage and Selection Operator and multivariate Cox regression. The tumor risk score was divided into high- and low-risk groups. The entire cohort was randomly divided into a 2:1 training cohort and a test cohort for internal validation to assess the feasibility of the risk model. The infiltration of immune cells was obtained using 'CIBERSORT,' and the infiltration of immune subgroups in high- and low-risk groups was analyzed. The GC immune score data were obtained and the difference in immune scores between the two groups was analyzed.

RESULTS

We collected 412 GC and 36 adjacent tissue samples, and identified 3627 DEGs and 1311 IRGs. A total of 482 DEIRGs were obtained. GO analysis showed that DEIRGs were mainly distributed in immunoglobulin complexes, receptor ligand activity, and signaling receptor activators. KEGG pathway analysis showed that the top three DEIRGs enrichment types were cytokine-cytokine receptors, neuroactive ligand receptor interactions, and viral protein interactions. We ultimately obtained an immune-related signature based on 10 genes, including 9 risk genes (LCN1, LEAP2, TMSB15A mRNA, DEFB126, PI15, IGHD3-16, IGLV3-22, CGB5, and GLP2R) and 1 protective gene (LGR6). Kaplan-Meier survival analysis, receiver operating characteristic curve analysis, and risk curves confirmed that the risk model had good predictive ability. Multivariate COX analysis showed that age, stage, and risk score were independent prognostic factors for patients with GC. Meanwhile, patients in the low-risk group had higher tumor mutation burden and immunophenotype, which can be used to predict the immune checkpoint inhibitor response. Both cytotoxic T lymphocyte antigen4+ and programmed death 1+ patients with lower risk scores were more sensitive to immunotherapy.

CONCLUSION

In this study a new prognostic model consisting of 10 DEIRGs was constructed based on the TME. By providing risk factor analysis and prognostic information, our risk model can provide new directions for immunotherapy in GC patients.

Preoperative Risk Factors and Prognostic Impact of Postoperative Complications Associated with Total Gastrectomy

INTRODUCTION

We evaluated the risk factors for patients with gastric cancer (GC) undergoing total gastrectomy (TG) that predict postoperative complications, including anastomotic leakage, postoperative pneumonia, and heart disease.

METHODS

We collected 106 patients who received TG for GC between May 2009 and May 2017 at Gunma University Graduate School of Medicine, including clinicopathologic, surgical, postoperative complication, laboratory test, and physiologic test data.

RESULTS

Of 106 patients, 92 (86.8%) had no complications, and 14 (13.2%) had complications. Univariate analyses revealed that a high American Society of Anaesthesiologists physical status (ASA-PS) and neutrophil-lymphocyte ratio (NLR) of ≥3.5 significantly correlated with postoperative complications. Multivariate analyses showed that high ASA-PS was an independent prognostic factor of postoperative complications. The cancer recurrence rate was 34.8% in the noncomplication group and 71.4% in the complication group.

CONCLUSION

Patients with postoperative complications are prone to recurrence and poor prognosis. For patients with high-risk GC with poor ASA-PS and high NLR, more thorough perioperative management is essential.

Dismal prognosis of elderly gastric cancer patients who underwent gastrectomy with American Society of Anesthesiologists (ASA) 3

BACKGROUND

Although the American Society of Anesthesiologists (ASA) score of 3 is relatively common in elderly patients, there have been few debates on the indications for gastrectomy in elderly gastric cancer (GC) patients with ASA3. Therefore, this study aimed to investigate gastrectomy's clinical relevance in elderly patients with GC and ASA3.

METHODS

We retrospectively analyzed 228 consecutive elderly GC patients (aged ≥ 75 years) without prior treatments who underwent curative gastrectomy between 2013 and 2017.

RESULTS

Thirty-three patients with ASA3 showed significantly poorer prognosis than those with ASA1 and 2 (p = 0.004). The multivariate Cox proportional hazards model showed that ASA3 (p = 0.021) and pStage (p = 0.007) were independent prognostic factors, respectively. Elderly GC patients with pStage III and ASA3 exhibited uniquely dismal prognosis (p < 0.001); however, several survivors were still confirmed. Postoperative complications (PCs) were only the final remnant independent prognostic factor (p = 0.020) among the 33 elderly GC patients with ASA3, where dead patients included cancer-specific and other deaths, especially pneumonia. PCs were independently associated with prognostic nutritional index (PNI) (< 42.7) in elderly GC patients, and the most frequent complication was pneumonia, which was significantly associated with ASA3 and marginally associated with PNI in a multivariate analysis.

CONCLUSIONS

ASA3 has a dismal prognosis after curative gastrectomy in the elderly GC patients, but the number of survivors was confirmed. Curative gastrectomy is not considered contraindicated even in elderly GC with ASA3. Preoperative malnutrition is associated with PCs, which proposing preoperative nutritional intervention in the context of treatment strategy for the elderly GC patients with ASA3.

[BUB1 gene is highly expressed in gastric cancer:analysis based on Oncomine database and bioinformatics]

OBJECTIVE

To investigate the expression of BUB1 gene in gastric cancer.

METHODS

Oncomine, GEPIA, BioGPS and Kaplan-Meier Plotter databases were used to analyze the difference of BUB1 gene expression between gastric cancer tissue and normal gastric tissue. The association of BUB1 expression level with the prognosis of gastric cancer patients was also analyzed. The Cancer Cell Line Encyclopedia (CCLE) was explored to analyze the expression of BUB1 in T cells and B cells in gastric cancer patients, and the String database was used to generate the network map of BUB1-related proteins and functional annotation of gene ontology (GO). The related pathways of KEGG were analyzed. Tumor immune assessment resource (TIMER) database was used to analyze the expression of BUB1 in immune infiltration and its effect on prognosis of gastric cancer patients. To further verify the results of gene chip analysis in Oncomine database, we collected 30 pairs of surgical specimens of gastric adenocarcinoma and adjacent tissues from patients admitted to the First Affiliated Hospital of Chengdu Medical College from March, 2018 to July, 2019. The results of BUB1 gene expression in Oncomine database were verified by PCR and immunohistochemistry.

RESULTS

Oncomine, GEPIA and BioGPS analyses showed that BUB1 was highly expressed in gastric cancer compared with normal gastric tissue. Kaplan-Meier survival analysis showed that the progression-free survival time (HR=0.52, 95% CI:0.41-0.67, P &lt; 0.05) and the overall survival time (HR=0.67, 95% CI:0.55-0.82, P &lt; 0.05) were prolonged in gastric cancer patients with a high expression of BUB1. Through String data collection, BUB1-related proteins were mainly enriched in 13 cellular components, 4 molecular functions and 12 biological processes, involving 4 signal pathways. TIMER database analysis showed that CD4⁺ T cells and macrophages with high expressions of BUB1 mRNA in the immune microenvironment were associated with a favorable 5-year survival outcome of patients with gastric cancer. In the surgical specimens, real-time quantitative PCR showed that the expression level of BUB1 mRNA was significantly higher in gastric cancer tissues than in the adjacent gastric mucosa tissues, and immunohistochemical results demonstrated positive BUB1 staining in the gastric cancer tissues.

CONCLUSIONS

BUB1 gene is highly expressed in gastric cancer. BUB1 may reduce tumor immunosuppression and helps to evaluate the prognosis of patients with gastric cancer.