Evaluation of Peroperative and Oncological Results in Laparoscopic Surgery of Gastric Cancer in Elderly Patients: Single-Center Study

Elderly patients with stage II gastric cancer do not benefit from adjuvant chemotherapy

BACKGROUND

With the aging of the population, the burden of elderly gastric cancer (EGC) increases worldwide. However, there is no consensus on the definition of EGC and the efficacy of adjuvant chemotherapy in patients with stage II EGC. Here, we investigated the effectiveness of adjuvant chemotherapy in defined EGC patients.

METHODS

We enrolled 5762 gastric cancer patients of three independent cohorts from the Sixth Affiliated Hospital of Sun Yat-sen University (local), the Surveillance, Epidemiology, and End Results (SEER), and the Asian Cancer Research Group (ACRG). The optimal age cutoff for EGC was determined using the K-adaptive partitioning algorithm. The defined EGC group and the efficacy of adjuvant chemotherapy for them were confirmed by Cox regression and Kaplan-Meier survival analyses. Furthermore, gene set variation analyses (GSVA) were performed to reveal pathway enrichment between groups.

RESULTS

The optimal age partition value for EGC patients was 75. In the local, SEER, and ACRG cohorts, the EGC group exhibited significantly worse overall survival and cancer-specific survival than the non-EGC group (P < 0.05) and was an independent risk factor. Stratified analyses based on chemotherapy showed that EGC patients derived little benefit from adjuvant chemotherapy. Furthermore, GSVA analysis revealed the activation of DNA repair-related pathways and downregulation of the p53 pathway, which may partially contribute to the observed findings.

CONCLUSION

In this retrospective, international multi-center study, 75 years old was identified as the optimal age cutoff for EGC definition, and adjuvant chemotherapy proved to be unbeneficial for stage II EGC patients.

Identification of optimal primary tumor resection candidates for metastatic gastric cancer: Nomograms based on propensity score matching

BACKGROUND

This study sought to develop and validate nomograms for screening patients with metastatic gastric cancer (mGC) who are candidates for primary tumor resection (PTR) and evaluating the prognosis of mGC patients after PTR.

METHODS

From 2010 to 2016, we screened mGC patients with complete data from the Surveillance, Epidemiology, and End Results (SEER) database. Depending on whether or not PTR was performed, we categorized patients into surgery and non-surgery groups. A 1:1 propensity score matching (PSM) analysis was used to balance the characteristics of the two groups. The endpoints were overall survival (OS) and cancer-specific survival (CSS). Two predictive nomograms were developed using logistic regression to assess the likelihood of benefit. Two additional prognostic nomograms were developed to assess prognosis in mGC patients after PTR by Cox regression. Finally, nomograms were evaluated using a variety of methodologies.

RESULTS

Our study included 3594 mGC patients who met the criteria. PTR was associated with improved OS and CSS time (median OS time after PSM: 15 vs. 7 months, P < 0.05; median CSS time after PSM: 17 vs. 7 months, P < 0.05). The OS-related predictive nomogram, including age, histologic type, grade, T stage, and chemotherapy, was developed. Moreover, the CSS-related predictive nomogram, including age, histologic type, grade, and chemotherapy, was developed. Sex, histologic type, grade, T stage, N stage, and chemotherapy were found to be correlated with OS. Furthermore, the CSS correlated with histologic type, grade, T stage, N stage, and chemotherapy. Both predictive and prognostic nomograms were found to be valuable and reliable after different types of validation.

CONCLUSION

Predictive nomograms were developed and validated for identifying the optimal PTR mGC candidates. Prognostic nomograms were developed and validated for assessing the prognosis of mGC patients after PTR.

miR-125a-5p promotes gastric cancer growth and invasion by regulating the Hippo pathway

OBJECTIVE

This study was carried out to explore the potential involvement of miR-125a-5p in the oncogenic effects of EphA2, TAZ, and TEAD2 and the activity of the Hippo signaling pathway in gastric cancer progression.

METHODS

In vitro transfection of miR-125a-5p mimics or inhibitors, qRT-PCR, colony formation assays, and cell invasion assays were used to assess the effect of miR-125a-5p on the growth and invasion in gastric cancer (GC). Male nude mice bearing tumors derived from human GC cells were used for evaluating the effects of miR-125a-5p on tumor growth. Luciferase reporter assay, immunofluorescence, immunohistochemistry, qRT-PCR, and immunoblotting were performed to explore the role of miR-125a-5p in the epithelial-mesenchymal transition (EMT) and association among miR-125a-5p, EphA2, TAZ, and TEAD2 in GC cells.

RESULTS

MiR-125a-5p enhanced GC cell viability and invasion in vitro, whereas inhibition of miR-125a-5p using a specific inhibitor and antagomir suppressed cancer cell invasion and tumor growth. Moreover, inhibition of miR-125a-5p reversed EMT in vitro. miR-125a-5p upregulated the expression of EphA2, TAZ, and TEAD2, promoted TAZ nuclear translocation, and induced changes in the activity of the Hippo pathway by enhancing the expression of TAZ target genes. Finally, miR-125a-5p was overexpressed in late-stage GCs, and positive correlations were observed with its targets EphA2, TAZ, and TEAD2.

CONCLUSION

miR-125a-5p can promote GC growth and invasion by upregulating the expression of EphA2, TAZ, and TEAD2.