Risk factors for recurrence of gastric cancer after curative laparoscopic gastrectomy

Development and validation of nomograms for predicting the prognosis of early and late recurrence of advanced gastric cancer after radical surgery based on post-recurrence survival

In this study, we aimed to explore the risk factors influencing post-recurrence survival (PRS) of early recurrence (ER) and late recurrence (LR) in stage advanced gastric cancer (AGC) patients after radical surgery, respectively, and to develop predictive models in turn. Medical records of 192 AGC patients who recurred after radical gastrectomy were retrospectively reviewed. They were randomly divided into the training and validation set at a ratio of 2:1. Nomograms were built based on risk factors influencing PRS of ER and LR explored by Cox regression analyses, respectively. Concordance index (C-index) values and calibration curves were used to evaluate predictive power of nomograms. Body mass index < 18.5 kg/m2, prealbumin level < 70.1 mg/L, positive lymph nodes ratio ≥ 0.486 and palliative treatment after recurrence were independent risk factors for the prognosis of ER. In contrast, prealbumin level < 170.1 mg/L, CEA ≥ 18.32 μg/L, tumor diameter ≥ 5.5 cm and palliative treatment after recurrence were independent risk factors for the prognosis of LR. The C-index values were 0.801 and 0.772 for ER and LR in the training set, respectively. The calibration curves of validation set showed a C-index value of 0.744 and 0.676 for ER and LR, respectively. Nomograms which were constructed to predict the prognosis of ER and LR of AGC after surgery showed great predictive power and could provide reference for clinicians' treatment strategies to some extent.

A practical recurrence risk model based on Lasso-Cox regression for gastric cancer

INTRODUCTION

Gastric cancer remains huge cancer threat worldwide. Detecting the recurrence of gastric cancer after treatment is especially important in improving the prognosis of patients. We aim to fit different risk models with different clinical variables for patients with gastric cancer, which further provides applicable guidance to clinical doctors for their patients.

METHODS

We collected the primary data from the medical record system in Lanzhou University Second Hospital and further cleaned the primary data via assessing data integrity artificially; meanwhile, detailed conclusion criteria and exclusion criteria were made. We used R software (version 4.1.3) and SPSS 25.0 to analyze data and build models, in which SPSS was used to analyze the correlation and difference of different items in the training set and testing set, and different R packages were used to run LASSO regression, Cox regression and nomogram for variable selection, model construction and model validation.

RESULT

A total of 649 patients were included in our data analysis and model building. In LASSO regression selection, seven variables, pathological stage, tumor size, the number of total lymph nodes, the number of metastatic lymph nodes, intraoperative blood loss (IBL), the level of AFP and CA199, showed their correlation to the dependent variable. The multivariable Cox regression model fitted using these seven variables showed medium prediction ability, with an AUC of 0.840 in the training set and 0.756 in the testing set.

CONCLUSIONS

Pathological stage, tumor size, the number of total lymph nodes, the number of metastatic lymph nodes, IBL, the level of AFP and CA199 are significant in identifying recurrence risk for gastric cancer patients after radical gastrectomy.

Effect of hyperthermic intraperitoneal chemotherapy on survival and recurrence rates in advanced gastric cancer: a systematic review and meta-analysis

BACKGROUND

Around 5-20% of patients who undergo surgery for advanced gastric cancer (AGC), which invades into the muscularis propria or beyond, have peritoneal carcinomatosis. The peritoneal recurrence rate is 10-54%, which is associated with a poor prognosis. The role of hyperthermic intraperitoneal chemotherapy (HIPEC) in AGC with and without peritoneal carcinomatosis is not clearly defined.

METHODS

The authors conducted a meta-analysis, in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, of the clinical trials and high-quality nonrandomized studies evaluating the role of HIPEC in AGC over the last 10 years. The studies were searched in PubMed, EMBASE, MEDLINE, and Cochrane databases between January 2011 to December 2021. Clinical data including overall survival, recurrence free survival, overall recurrence rate, peritoneal recurrence rate, and complications analyzed using RevMan 5.4.

RESULTS

Six randomized controlled trials and 10 nonrandomized studies, comprising a total of 1700 patients were included. HIPEC was associated with significantly improved OS at 3 [odd ratio (OR) 1.89, 95% CI: 1.17-3.05] and 5 years (OR 1.87, 95% CI: 1.29-2.71). HIPEC was associated with reduced overall recurrence (OR 0.49, 95% CI: 0.31-0.80) and peritoneal recurrence (OR 0.22, 95% CI: 0.11-0.47). HIPEC was not associated with increased complications. The occurrence of postoperative renal dysfunction was significantly higher in the HIPEC group (OR 3.94, 95% CI: 1.85-8.38).

CONCLUSION

The role of HIPEC in AGC has evolved over the past decade. HIPEC may improve survival rates and reduce recurrence rates in patients with AGC, without significant increase in complications and with a favorable impact on 3 and 5-year survival.

Meta-Analysis of the Effects of Three-Dimensional Visualized Medical Techniques Hepatectomy for Liver Cancer with and without the Treatment of Sorafenib

Background

The application of medical image three-dimensional (3D) reconstruction technology can provide intuitive 3D image data support for accurate preoperative evaluation, surgical planning, and operation safety. However, there is still a lack of high-quality evidence to support whether 3D reconstruction technology is more advantageous in liver resection. Therefore, this study systematically evaluated the clinical effects of 3D reconstruction and two-dimensional (2D) image-assisted hepatectomy.

Methods

Databases were searched to collect published clinical studies on 3D reconstruction technology and 2D image-assisted liver resection. Data were extracted from the database construction to March 2022 and the risk of bias in the included studies was evaluated. Meta-analysis was performed using RevMan5.3 software.

Results

A total of 13 clinical studies were included, including 1616 patients, 795 in the 2D group and 819 in the 3D group. The meta-analysis showed that the incidence of postoperative complications was lower in the 3D group than in the 2D group (OR = 0.64, 95% CI = 0.49–0.83, P=0.001) and also reduced operation time (SMD = −0.51, 95% CI = −0.74∼−0.27, P < 0.0001), decreased intraoperative blood loss (SMD = −63.85, 95% CI = −98.66–29.04, P=0.0003), decreased incidence of postoperative liver failure (OR = 2.42, 95% CI = 0.99–5.95, P=0.05), decreased postoperative recurrence rate (OR = 0.29, 95% CI = 0.16–0.53, P < 0.0001), and increased postoperative survival rate (OR = 2.19, 95% CI = 1.49–3.23, P < 0.0001).

Conclusions

Current data suggest that 3D reconstruction-assisted hepatectomy can reduce intraoperative blood loss, postoperative complications, and recurrence, and improve postoperative survival. Therefore, the 3D reconstruction technique is worthy of application and promotion in assisted liver resection.

Effects of Laparoscopic versus Open Surgery for Advanced Gastric Cancer after Neoadjuvant Chemotherapy: A Meta-Analysis

Objective

To evaluate the efficacy of laparoscopy and laparotomy after neoadjuvant chemotherapy in the treatment of advanced gastric cancer by meta-analysis.

Methods

Cochrane Library, Embase, and PubMed were searched by computer until December 1, 2021. Literature was screened according to inclusion and exclusion criteria, and relevant data were extracted for meta-analysis using RevMan 5.3.

Results

A total of 1027 patients from 11 literature studies were included in this study, including 413 patients in the laparoscopic group and 614 patients in the open group. Meta-analysis showed that the laparoscopic group had less intraoperative bleeding (SMD = -1.11; 95% CI: -1.75-0.47; P=0.0006), early postoperative exhaust (SMD = -0.45; 95% CI: -0.70-0.20; P=0.0004), and shorter postoperative hospital stay (SMD = 0.97; 95% CI: 1.69∼0.26; P=0.008), but had longer the operation time (SMD = 0.65; 95% CI: 0.52∼0.79; P < 0.00001). There was no significant difference in the number of lymph nodes dissected during operation (SMD = -0.45; 95% CI: -0.42-0.19; P=0.45), the incidence of surgical complications 30 days after operation (OR = 0.78; 95% CI: 0.53∼1.13; P=0.19), time of first defecation (MD = 0.00; 95% CI: -0.10∼0.10; P=0.98), and time of first postoperative feeding (MD = -0.05; 95% CI: -0.22∼0.12; P=0.54) between the two groups. For long-term prognosis, there was no significant difference in the 3-year overall survival rate after operation between the two groups (RR = 0.84; 95% CI: 0.63-1.12; P=0.23).

Conclusion

Compared with the open stomach cancer surgery, laparoscopic gastric cancer surgery has less intraoperative blood loss, shorter hospitalization time, and advantages such as early rehabilitation, postoperative complications rate, and long-term survival, which confirmed the validity and security of the laparoscopic surgery.

Preoperative Low Prealbumin Is Associated With Recurrence in Patients With Stage II/III Gastric Cancer After Laparoscopic D2 Gastrectomy

Background

Postoperative recurrence is associated with poor prognosis in patients with gastric cancer. This study aimed to explore predictive factors contributing to recurrence in patients with stage II/III gastric cancer after laparoscopic D2 gastrectomy.

Methods

This retrospective study was conducted at a single tertiary referral hospital. Patients diagnosed with gastric cancer who met the inclusion criteria were included in the study. The clinicopathological characteristics of the patients were collected. The patients were divided into recurrence and non-recurrence groups. The predictive factors were investigated using univariate and multivariate analyses.

Results

In total, 462 patients were included. The incidence of recurrence was 26.4% (122/462) in all patients. The most common recurrence pattern was haematogenous recurrence. In the multivariate analysis, the independent predictive factors for recurrence were serum prealbumin level (p &lt; 0.001), prognostic nutritional index (p = 0.001), carbohydrate antigen 19-9 (CA19-9) (p &lt; 0.001), number of lymph node metastases (p &lt; 0.001), signet-ring cell carcinoma (p = 0.001), tumor deposit (p = 0.001), and no/incomplete adjuvant chemotherapy (p &lt; 0.001).

Conclusions

Our findings revealed that nutritional status was an independent predictive factor for recurrence in patients with gastric cancer after D2 gastrectomy. We suggest that patients with risk factors for recurrence receive both nutritional support and intense surveillance.

Preoperative Folate Receptor-Positive Circulating Tumor Cells Are Associated With Occult Peritoneal Metastasis and Early Recurrence in Gastric Cancer Patients: A Prospective Cohort Study

Background

The aim of this study is to explore the clinical feasibility of detecting folate receptor-positive circulating tumor cells (FR+ CTCs) for predicting peritoneal metastasis and short-term outcome in gastric cancer patients.

Methods

This is a prospective, single-center, observational study. We applied ligand-targeted enzyme-linked polymerization method to detect preoperative FR+ CTC levels in peripheral blood. We evaluated the diagnostic value of FR+ CTCs and other biomarkers in predicting peritoneal metastasis. Prognostic factors for recurrence-free survival (RFS) were investigated in univariate and multivariate analyses.

Results

A total of 132 patients with gastric cancer and 9 patients with benign disease were recruited. Gastric cancer patients had a significantly higher CTC level compared to that of patients with benign disease (p < 0.01). Combined model including CTC level and other biomarkers presented high sensitivity (100%) and moderate specificity (59.3%) in predicting peritoneal metastasis. Univariate analysis revealed that decreased serum prealbumin, decreased peripheral lymphocyte count, FR+ CTCs, carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and lymph node metastasis were significantly associated with shorter RFS. FR+ CTC level [≥12.6 folate units (FU)/3 ml, hazard ratio (HR) = 6.957, p = 0.005] and CA19-9 (>34 ng/ml, HR = 3.855, p = 0.037) were independent prognostic factors in multivariate analysis.

Conclusions

Our findings for the first time suggested the diagnostic value of preoperative CTC levels in predicting peritoneal metastasis in gastric cancer. Moreover, the FR+ CTC level could be a novel and promising prognostic factor for the recurrence of gastric cancer in patients who underwent surgery.

Clinical Trial Registration

Chinese Clinic Trial Registry, identifier ChiCTR2100050514.

Solitary port-site metastasis 42 months after laparoscopic distal gastrectomy for gastric cancer

We report a case of solitary port-site recurrence after laparoscopy-assisted distal gastrectomy for advanced gastric cancer. A 66-year-old man had previously undergone laparoscopy-assisted gastrectomy with regional lymph-node dissection for advanced gastric cancer, which was a poorly differentiated adenocarcinoma invading the subserosal layer with lymphatic infiltration and no lymph-node metastases. He experienced dull pain in the left upper quadrant of the abdomen 42 months after the surgery. On physical examination, erythematous induration of the skin around the scar of the port insertion was observed in the left upper quadrant of the abdomen. Abdominal ultrasonography and contrast-enhanced computed tomography revealed a subcutaneous lesion with a well-defined mass measuring 3.0 cm in diameter located in the left upper quadrant of the abdomen. A skin biopsy revealed a metastatic adenocarcinoma from gastric cancer. Since there was no evidence of further metastatic lesions in other organs, the patient underwent surgical resection of the metastatic tumor arising at the port site. The abdominal wall tumor was resected with a leaf-skin incision and an adequate safety margin, and the inferior border of the tumor reached the muscular layer, which was resected with the tumor. Pathological examination confirmed the diagnosis of a poorly differentiated adenocarcinoma in the subcutaneous tissue with invasion of the muscle layer at the port site. The postoperative course was uneventful; chemotherapy using oxaliplatin plus S-1 was administered, and the patient was in good health with no evidence of the disease for 3 months postoperatively. Although port-site metastasis after laparoscopic gastrectomy for gastric cancer is a rare recurrence form, we should be aware of this issue, and further studies and assessments of additional cases are needed to establish a treatment strategy.

Upregulation of Linc-ROR Promotes the Proliferation, Migration, and Invasion of Gastric Cancer Cells Through miR-212-3p/FGF7 Axis

Background

Linc-ROR is a long non-coding RNA, that is found aberrantly expressed in various human cancers. We aim here to unveil the role of Linc-ROR in gastric cancer (GC) progression.

Methods

qPCR was used to determine gene expression. Cell viability was measured by CCK-8 assay. Transwell assays were performed to evaluate the GC cells’ migratory and invasive abilities. Xenograft mouse model was conducted to measure tumor growth.

Results

We found that Linc-ROR were overexpressed in GC tissues compared to the adjacent tissues. High Linc-ROR predicts poor prognosis of GC patients. The prediction of bioinformatics online revealed that Linc-ROR could bind to miR-212-3p. Further, dual-luciferase reporter assay confirmed a direct interaction between Linc-ROR and miR-212-3p. Overexpression of miR-212-3p facilitated GC cells’ migration and invasion, while the silencing of miR-212-3p attenuated GC cell migratory and invasive abilities. Moreover, Linc-ROR knockdown significantly suppressed the proliferation, migration, and invasion of GC cells, whereas miR-212-3p antagomir partially reversed Linc-ROR knockdown-induced phenotypes. Fibroblast growth factor 7 (FGF7), a downstream molecule of miR-212-3p, was overexpressed in GC cells. The recovery of FGF7 expression partially reversed the phenotypes caused by Linc-ROR silencing. Mechanistically, silencing of Linc-ROR contributed to the downregulation of CDK4, CDK6, Cyclin D1, N-Cadherin, Vimentin, MMP-9, MMP-2, but caused the upregulation of P21, P27, E-Cadherin, CK-19 in MGC-803 cells; however, FGF7 treatment could reverse the results induced by Linc-ROR silencing. Results in vivo further suggested that Linc-ROR knockdown repressed GC tumor growth, where the expression of miR-212-3p was up-regulated and FGF7 expression was downregulated in tumor tissues of mice.

Conclusion

These findings indicated that Linc-ROR/miR-212-3p/FGF7 axis played an important role in gastric cancer progression. Linc-ROR expression level was associated with the prognosis of GC patients.

Role of prophylactic hyperthermic intraperitoneal chemotherapy in patients with locally advanced gastric cancer

BACKGROUND

Gastric cancer is the second most common malignant tumor in China, ranking third among all malignant tumor mortality rates. Hyperthermic intraperitoneal chemotherapy (HIPEC) has been shown to increase significantly the effectiveness of intraperitoneal chemotherapeutic drugs, prolong the action time of these drugs on intraperitoneal tumor cells, and enhance their diffusion in tumor tissues. HIPEC may be one of the best choices for the eradication of residual cancer cells in the abdominal cavity.

AIM

The aim of this study was to study the role of preventive HIPEC after radical gastrectomy.

METHODS

A prospective analysis was performed with patients with cT₄N_0-3M₀ gastric cancer to compare the effects of postoperative prophylactic HIPEC plus intravenous chemotherapy with those of routine adjuvant chemotherapy. Patients’ medical records were analyzed, and differences in the peritoneal recurrence rate, disease-free survival time, and total survival time between groups were examined.

RESULTS

The first site of tumor recurrence was the peritoneum in 11 cases in the conventional adjuvant chemotherapy group and in 2 cases in the HIPEC group (P = 0.020). The 1-year and 3-year disease-free survival rates were 91.9% and 60.4%, respectively, in the conventional adjuvant chemotherapy group and 92.1% and 63.0%, respectively, in the HIPEC group. The 1-year and 3-year overall survival rates were 95.2% and 66.3%, respectively, in the conventional adjuvant chemotherapy group and 96.1% and 68.6%, respectively, in the HIPEC group. No significant difference in postoperative or chemotherapy complications was observed between groups.

CONCLUSION

In patients with cT₄N_0-3M₀ gastric cancer, prophylactic HIPEC after radical tumor surgery is beneficial to reduce peritoneal tumor recurrence and prolong survival.

Prognostic impact of D2-plus lymphadenectomy and optimal extent of lymphadenectomy in advanced gastric antral carcinoma: Propensity score matching analysis

OBJECTIVE

To investigate the prognostic impact of D2-plus lymphadenectomy including the posterior (No. 8p, No. 12b/p, No. 13, and No. 14v), and para-aortic (No. 16a2, and No. 16b1) lymph nodes (LNs) in subtotal gastrectomy for advanced gastric antral carcinoma.

METHODS

A total of 203 patients with advanced gastric cancer (GC) located in the antrum, who underwent R0 gastrectomy with D2 or D2-plus lymphadenectomy between January 2003 and December 2011 were enrolled. Propensity score matching was used to reduce the strength of the confounding factors to accurately evaluate prognoses. The therapeutic value index (TVI) was calculate to evaluate the survival benefit of dissecting each LN station.

RESULTS

Of 102 patients with D2-plus lymphadenectomy, 21 (20.59%) were pathologically identified as having LN metastases beyond the extent of D2 lymphadenectomy. After matching, the overall survival (OS) was significantly better in the D2-plus than the D2 group (P=0.030). In the multivariate survival analysis, D2-plus lymphadenectomy (hazard ratio, 0.516; P=0.006) was confirmed to significantly improve the survival rate. In the logistic regression analysis, pN stage [odds ratio (OR), 2.533; 95% confidence interval (95% CI), 1.368-4.691; P=0.003] and extent of LNs metastasis (OR, 5.965; 95% CI, 1.335-26.650; P=0.019) were identified as independent risk factors for LN metastases beyond the extent of D2 lymphadenectomy. The TVI of patient with metastasis to LNs station was 7.1 (No. 8p), 5.7 (No. 12p), 5.1 (No. 13), and 7.1 (both No. 16a2 and No. 16b1), respectively.

CONCLUSIONS

D2-plus lymphadenectomy may improve the prognoses of some patients with advanced GC located in the antrum, especially for No. 8p, No. 12b, No. 13, and No. 16.

Comparison of open gastrectomy and the laparoscopic procedure in advanced gastric cancer

INTRODUCTION AND AIM

Gastric cancer is one of the most frequent neoplasias in Peru and worldwide, with surgery as the only potentially curative or palliative treatment. Laparoscopic gastrectomy is the most frequent alternative surgical technique utilized, but one of its main drawbacks is the technical difficulty involved in perigastric lymphadenectomy. The aim of the present study was to evaluate the clinical and surgical characteristics, postoperative complications, and survival rate in patients with advanced gastric cancer that underwent open gastrectomy or laparoscopic gastrectomy at the Hospital Nacional P.N.P "Luis N. Sáenz" in Lima, Peru, within the time frame of 2005 to 2014.

MATERIALS AND METHODS

An analytic, longitudinal, retrospective cohort study was conducted on 482 patients that underwent surgery for gastric cancer, within the time frame of January 2005 to December 2014. The clinical, epidemiologic, and postoperative characteristics were evaluated, and a survival analysis was carried out.

RESULTS

Of the 475 patients included in the study, 236 underwent open gastrectomy and 239 had laparoscopic gastrectomy. Median follow-up time was 61.9 months in the open surgery group and 46.7 months in the laparoscopy group. There were fewer postoperative complications in the laparoscopy group and no statistically significant difference between the two groups in relation to the survival analysis.

CONCLUSIONS

In our study, laparoscopic gastrectomy resulted in fewer postoperative complications, compared with the open procedure, but did not modify overall survival during the follow-up period.

A comprehensive evaluation of clinical efficacy and safety of celecoxib in combination with chemotherapy in metastatic or postoperative recurrent gastric cancer patients: A preliminary, three-center, clinical trial study

AIM

To evaluate the efficacy and safety of celecoxib combined with chemotherapy in the treatment of metastatic or postoperative recurrent gastric cancer.

METHODS

This preliminary, three-center, clinical trial study was conducted between September 2010 and December 2016. In the experimental group (n = 100), patients were treated with celecoxib combined with chemotherapy, and chemotherapy alone was used in the control group. Progression-free survival (PFS) was considered as the primary efficacy parameter. Overall survival (OS), remission rate (RR), quality of life (QOL) and drug safety were considered as the secondary efficacy parameters.

RESULTS

The PFS of the experimental group was 6 months, which was not significantly longer than that of the control group (5 months, P = .73). The average OS was not significantly different between the experimental group (12 months) and the control group (10 months, P = .59). The average OS of the COX-2 positive patients in the experimental group was 14 months and it was significantly longer than the 10-month OS in the control group (P = .01). The PFS of the COX-2 positive patients in the experimental group was 7.5 months, significantly longer than the 5-month PFS of patients in the control group (P < .001). No statistical significance was identified in the incidence of nausea, neutropenia, anorexia, peripheral neurotoxicity, diarrhea, vomiting, asthenia and thrombocytopenia. The EORTC QLQ-C30 questionnaire revealed that the overall QOL of the experimental group was significantly higher than that of the control group (P < .05). No statistical significance was found in the scores of functioning scale between the 2 groups. However, the scores of the symptom scale, especially for pain and fatigue in the experimental group was remarkably higher than that in the control group (P < .05). The overall score of EORTC QLQ-STO22 for the experimental group was considerably higher compared to that for the control group (P < .05). No statistical significance was identified in term of the domains of restrictions on feeding, dysphagia, anxiety, reflux, sense of taste, dry mouth, hair loss and body shape between the 2 groups (P > .05 for all mentioned outcomes).

CONCLUSION

Celecoxib combined with chemotherapy offers more clinical benefits for COX-2 positive advanced gastric cancer patients.

Comparative analysis of robotic gastrectomy and laparoscopic gastrectomy for gastric cancer in terms of their long-term oncological outcomes: a meta-analysis of 3410 gastric cancer patients

BACKGROUND

Data regarding the long-term oncological outcomes of robotic gastrectomy (RG) are limited despite the increased commonality of this method as an alternative for gastric cancer treatment. Here, we conducted a meta-analysis to evaluate the long-term oncological outcomes of RG in comparison to that of laparoscopic gastrectomy (LG).

METHODS

The PubMed, ISI Web of Science, EMBASE, and Cochrane Library databases were comprehensively searched for studies that compared RG and LG in terms of their long-term survival outcomes. The hazard ratios (HRs) of overall survival (OS), disease-free survival (DFS), and relapse-free survival (RFS) were obtained, while the odds ratio (OR) was recorded for the recurrence rate. A sensitivity analysis was performed. Egger's test and Begg's test were applied to evaluate publication bias.

RESULTS

Eight studies were identified and involved 3410 gastric cancer patients (RG, 1009; LG, 2401). The two groups had no significant differences in OS (HR, 0.98; 95% CI, 0.80-1.20; P = 0.81), DFS (HR, 1.36; 95% CI, 0.33-5.59; P = 0.67), RFS (HR, 0.92; 95% CI, 0.72-1.19; P = 0.53), or recurrence rate (OR, 0.92; 95% CI, 0.71-1.19; P = 0.53). Moreover, the two techniques were comparable in length of hospital stay (LOS), postoperative complication rate, 30-day mortality rate, and rate of conversion to open surgery.

CONCLUSIONS

The long-term oncological outcomes, expressed as OS, DFS, RFS, and recurrence rate, were similar between RG and LG. However, more randomized controlled trials with rigorous study designs and patient cohorts are needed to evaluate the oncologic outcomes of RG in patients with gastric cancer.

Soluble PD-L1 Expression in Circulation as a Predictive Marker for Recurrence and Prognosis in Gastric Cancer: Direct Comparison of the Clinical Burden Between Tissue and Serum PD-L1 Expression

BACKGROUND

This study assessed programmed cell death ligand 1 (PD-L1) expression in primary tissues and soluble PD-L1 (sPD-L1) concentration in matched preoperative serum in gastric cancer (GC) patients to perform direct comparison between tissue and serum PD-L1 expression and to clarify the prognostic implication in GC.

METHODS

The study enrolled 180 GC patients who underwent surgery for GC at the authors' institution. The study evaluated tissue PD-L1 expression using immunohistochemistry and quantified sPD-L1 concentration in preoperative serum using enzyme-linked immunosorbent assay in GC patients.

RESULTS

The findings showed that PD-L1 was overexpressed in GC tissues compared with normal mucosa. Tissue PD-L1 expression was significantly higher in the GC patients with advanced T stage, presence of lympho-vascular invasion, lymph node metastasis, and peritoneal metastasis. Furthermore, elevated tissue PD-L1 expression was significantly associated with poor prognosis for overall survival (OS) and disease-free survival (DFS). Serum sPD-L1 was significantly higher in the GC patients than in the healthy volunteers. Although serum sPD-L1 was not correlated with any clinicopathologic factors, the patients with high serum sPD-L1 showed poorer OS and DFS than those with low sPD-L1. Multivariate analyses showed that both elevated tissue PD-L1 and serum sPD-L1 were independent prognostic factors for poor OS [tissue PD-L1: hazard ratio (HR), 4.28; 95% confidence interval (CI), 1.43-12.8; P = 0.0094 vs. serum sPD-L1: HR, 11.2; 95% CI, 3.44-36.7; P = 0.0001] and poor DFS (tissue PD-L1: HR, 6.96; 95% CI, 2.48-19.6; P = 0.0002 vs. serum sPD-L1: HR, 8.7; 95% CI, 3.16-23.9; P < 0.0001) for the GC patients. Furthermore, infiltrative CD8- and Foxp3-positive T cells were significantly increased in the GC patients with elevated tissue PD-L1 expression.

CONCLUSION

Both serum sPD-L1 and tissue PD-L1 expression may serve as predictive biomarkers for recurrence and prognosis in GC patients.

The anticipating value of PLK1 for diagnosis, progress and prognosis and its prospective mechanism in gastric cancer: a comprehensive investigation based on high-throughput data and immunohistochemical validation

Polo-like kinase 1 (PLK1) is a multi-functional protein and its aberrant expression is a driver of cancerous transformation and progression. To increase our understanding of the clinical value and potential molecular mechanism of PLK1 in gastric cancer (GC), we performed this comprehensive investigation. A total of 25 datasets and 12 publications were finally incorporated. Additional immunohistochemistry was conducted to validate the expression pattern of PLK1 in GC. The pooled standard mean deviation (SMD) indicated that PLK1 mRNA was up-regulated in GC (SMD=1.21, 95% CI: 0.65-1.77, P< 0.001). Similarly, the pooled odds ratio (OR) revealed that PLK1 protein was overexpressed in GC compared with normal gastric tissue (OR=12.12, 95% CI: 5.41-27.16, P<0.001). The area under the curve (AUC) of the summary receiver operating characteristic (SROC) curve was 0.86. Furthermore, our results demonstrated that GC patients with PLK1 overexpression were significantly associated with unfavorable overall survival (HR =1.54, 95% CI: 1.30–1.83, P<0.001), lymph node metastasis (OR = 1.78, 95% CI: 1.13–2.80, P=0.013) and advanced TNM stage (OR=1.48, 95% CI: 1.02-2.15, P=0.038). Altogether, 100 similar genes were identified by Gene Expression Profiling Interactive Analysis (GEPIA) and further with gene-set enrichment analysis. These genes were related to gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways relevant to the cell cycle. Gene set enrichment analysis (GSEA) indicated that PLK1 is associated with various cancer-related pathways. Collectively, this study suggests that PLK1 overexpression could play vital roles in the carcinogenesis and deterioration of GC via regulating tumor-related pathways.