A comparative study on perioperative outcomes between robotic versus laparoscopic D2 total gastrectomy.

OBJECTIVE: Robotic surgery has been increasingly used worldwide owing to its advanced features. However, the significant benefits of robotic total gastrectomy (RTG) over laparoscopic total gastrectomy (LTG) have yet to be demonstrated. We conducted a prospective cohort study to compare the safety and efficacy of robotic and laparoscopic total gastrectomy (LTG) with D2 lymphadenectomy for AGC. METHODS: Between March 26, 2018 and July 30, 2021, 155 patients between 18 and 80 years of age with locally advanced gastric cancer (cT2-4a, N0/+, M0) were enrolled. The perioperative outcomes within 30 days after surgery were compared between the RTG (n = 69) and LTG (n = 73) groups on a per-protocol (PP) basis. Postoperative complications were evaluated according to the Clavien-Dindo classification. RESULTS: The overall postoperative morbidity rate was 21.74% in the RTG group and 28.77% in the LTG group with no significant difference (P = 0.44), RTG was associated with a lower incidence of pneumonia (4.35% vs. 15.07%, P = 0.047). No mortality was observed in either group. There was no significant difference in the total operative time (284.48 vs. 271.73 min, P = 0.171), but RTG was associated with a lower estimated volume of blood loss (110 vs. 150 ml, P < 0.001) and more total retrieved lymph nodes (LNs) (41.36 vs 35.1, P = 0.019), more extraperigastric LNs (14.91 vs. 12.19, P = 0.024) and more LNs in the suprapancreatic areas (14.68 vs. 11.82, P = 0.017). The laboratory data (amylase, inflammatory, Albumin and T lymphocyte levels) of the RTG group were better than those of the LTG group. CONCLUSION: According to the results of this prospective cohort study, for patients with locally advanced gastric cancer, Robotic surgery has advantages over laparoscopic surgery for radical total gastrectomy with D2 lymphadenectomy performed by well-trained doctors.

Laparoscopic versus open gastrectomy for serosa-invasive gastric cancer: A single-center retrospective cohort study.

BACKGROUND: Whether laparoscopic gastrectomy is suitable for patients with serosa-invasive gastric cancer remains controversial. We performed this study to evaluate the short- and long-term outcomes after laparoscopic gastrectomy compared with after open gastrectomy. METHODS: We retrospectively analyzed 906 consecutive patients with serosa-invasive gastric cancer from January 2004 to December 2014 in our center, who underwent laparoscopic gastrectomy or open gastrectomy with D2 lymphadenectomy. After propensity score matching, 334 patients were included in each group. Surgical conditions and short- and long-term results were compared. RESULTS: Laparoscopic gastrectomy was associated with less estimated blood loss and longer operation time, while the number of harvested lymph nodes was not significantly different between laparoscopic gastrectomy and open gastrectomy. Patients who underwent laparoscopic gastrectomy had an earlier time to first flatus, first diet, and first ambulation and were discharged earlier. Overall and pulmonary postoperative complication rates were lower in the laparoscopic gastrectomy group. With a minimum follow-up of 60 months, the 5-year overall survival was 39.3% in the laparoscopic gastrectomy group and 34.3% in the open gastrectomy group, and the 5-year disease-free survival was 36.4% in the laparoscopic gastrectomy group and 32.7% in the open gastrectomy group. Laparoscopic gastrectomy was associated with better 5-year overall survival in patients aged ≥60 years. The overall recurrence rates and patterns were not significantly different between the 2 groups. CONCLUSION: Laparoscopic gastrectomy is an alternative surgical approach for patients with serosa-invasive gastric cancer in terms of short-term outcomes and long-term survival, and it might be more advantageous for certain populations.

Long-term oncologic outcomes of robotic versus laparoscopic gastrectomy for locally advanced gastric cancer: a propensity score-matched analysis of 1170 patients.

BACKGROUND: The robotic surgical system has several technical advantages over laparoscopic instruments. The technical feasibility and safety of robotic gastrectomy (RG) for gastric cancer have been reported by increasing number of studies. However, the long-term survival and recurrence outcomes after RG for locally advanced gastric cancer (AGC) have seldom been reported. This study aimed to compare long-term oncologic outcomes for patients with locally AGC after RG or laparoscopic gastrectomy (LG). METHODS: This study comprised 1170 patients underwent RG or LG, respectively, for locally AGC between March 2010 and February 2017. The primary outcome was the 3-year disease-free survival (DFS). The secondary endpoint included 3-year overall survival (OS) and recurrence patterns. One-to-one propensity score matching (PSM) was performed to reduce confounding bias. The outcomes were compared in PSM cohort. RESULTS: After PSM, a well-balanced cohort of 816 patients (408 in each group) were included in the analysis. The 3-year DFS rate was 76.2% in the robotic group and 70.1% in the laparoscopic group (P = 0.076). The 3-year OS rates was 76.7% in the robotic group and 73.3% in the laparoscopic group (P = 0.246). In the subgroup analyses for potential confounding variables, neither 3-year DFS nor 3-year OS survival were significantly different between the two groups (all P > 0.05). The two groups showed similar recurrence patterns within 3 years after surgery (P > 0.05). CONCLUSION: For patients with locally AGC, RG can result in comparable long-term survival outcomes without an increase in recurrence rate.

Incidence and risk factors of postoperative complications after robotic gastrectomy for gastric cancer: an analysis of 817 cases based on 10-year experience in a large-scale center.

BACKGROUND: In this study, we investigated the incidence and risk factors for postoperative complications after robotic gastrectomy (RG) in patients with gastric cancer. METHODS: A total of 817 patients who underwent RG for gastric cancer between March 2010 and August 2019 were analyzed retrospectively. Postoperative complications were categorized according to the Clavien-Dindo classification, and possible risk factors were evaluated. RESULTS: Among 817 patients who underwent RG, overall, severe, local and systemic complication rates were 13.8, 4.2, 7.0 and 6.9%, respectively. Multivariable analysis revealed that an age of 70 years or older (P < 0.001) and multiorgan resection (P = 0.031) were independent risk factors for the occurrence of overall complications. Multivariable analysis showed that an age of 70 years or older (P = 0.005) and surgeons' experience ≤ 25 cases (P = 0.004) were independent risk factors for severe complications. Regarding local complications, an age of 70 years or older (P < 0.001), multiorgan resection (P = 0.010) and surgeons' experience ≤ 25 cases (P = 0.005) were identified as independent risk factors. An age of 70 years or older (P < 0.001), a BMI of 25 or higher (P = 0.045) and the presence of comorbidity (P = 0.029) were identified as independent risk factors for systemic complications. CONCLUSIONS: The present study demonstrated that RG is a safe and feasible procedure for the treatment of gastric cancer, and it has an acceptable postoperative morbidity. Elderly patients and insufficient surgeon experience were two major risk factors for the occurrence of complications following RG. We suggest that surgeons choose patients in good condition during their RG learning phase to reduce learning-associated morbidity.

A Meta-Analysis of the Association Between the VEGF +936C>T Gene Polymorphism and Digestive System Cancer Susceptibility.

Background: We aimed to evaluate the association between the vascular endothelial growth factor (VEGF) gene +936C>T polymorphism and digestive system tumors using a meta-analysis. Methods: Studies of the association between the VEGF+936C>T polymorphism and digestive system tumors published before December 2019 were searched in PubMed, EMBASE, Web of Sciences, the Chinese Biological and Medical Database (CBM), and the China National Knowledge Infrastructure (CNKI). The odds ratio and the corresponding 95% confidence interval were used as the effect indicators. A meta-analysis of original data was performed with different genetic models using the Stata 13.0 software. The reliability of the association was evaluated using the heterogeneity test, sensitivity analysis, false-positive report probability (FPRP), and bias test. Results: This meta-analysis included 37 publications with a total of 8568 digestive system tumor patients and 10,870 cases in the control populations. The overall combined analyses showed that the VEGF+936C>T gene polymorphism was significantly correlated with digestive system cancer susceptibility with the T allele increasing the risk of digestive system cancers. A stratified analysis based on ethnicity showed that the VEGF+936C>T gene polymorphism significantly increased the risk of digestive system tumors in both Asian and Caucasian populations. Additional stratified analyses based on tumor type showed that the VEGF +936C>T gene polymorphism was associated with colorectal cancer, oral cancer, and esophageal cancer. The sensitivity analysis (p < 0.2) and FPRP results also confirmed the reliability of these associations. Conclusions: This meta-analysis supported previous findings that the VEGF +936C>T gene polymorphism is significantly associated with an increased risk of the development of digestive system malignant tumors. This association still requires large-scale epidemiological studies for further validation.

Deep sequencing of circulating tumor DNA detects molecular residual disease and predicts recurrence in gastric cancer.

Identifying locoregional gastric cancer patients who are at high risk for relapse after resection could facilitate early intervention. By detecting molecular residual disease (MRD), circulating tumor DNA (ctDNA) has been shown to predict post-operative relapse in several cancers. Here, we aim to evaluate MRD detection by ctDNA and its association with clinical outcome in resected gastric cancer. This prospective cohort study enrolled 46 patients with stage I-III gastric cancer that underwent resection with curative intent. Sixty resected tumor samples and 296 plasma samples were obtained for targeted deep sequencing and longitudinal ctDNA profiling. ctDNA detection was correlated with clinicopathologic features and post-operative disease-free (DFS) and overall survival (OS). ctDNA was detected in 45% of treatment-naïve plasma samples. Primary tumor extent (T stage) was independently associated with pre-operative ctDNA positivity (p = 0.006). All patients with detectable ctDNA in the immediate post-operative period eventually experienced recurrence. ctDNA positivity at any time during longitudinal post-operative follow-up was associated with worse DFS and OS (HR = 14.78, 95%CI, 7.991-61.29, p < 0.0001 and HR = 7.664, 95% CI, 2.916-21.06, p = 0.002, respectively), and preceded radiographic recurrence by a median of 6 months. In locoregional gastric cancer patients treated with curative intent, these results indicate that ctDNA-detected MRD identifies patients at high risk for recurrence and can facilitate novel treatment intensification studies in the adjuvant setting to improve survival.

Establishing high-accuracy biomarkers for colorectal cancer by comparing fecal microbiomes in patients with healthy families.

Colorectal cancer (CRC) causes high morbidity and mortality worldwide, and noninvasive gut microbiome (GM) biomarkers are promising for early CRC diagnosis. However, the GM varies significantly based on ethnicity, diet and living environment, suggesting varied GM biomarker performance in different regions. We performed a metagenomic association analysis on stools from 52 patients and 55 corresponding healthy family members who lived together to identify GM biomarkers for CRC in Chongqing, China. The GM of patients differed significantly from that of healthy controls. A total of 22 microbial genes were included as screening biomarkers with high accuracy in additional 46 cases and 40 randomly selected healthy adults in Chongqing (area under the receive-operation curve (AUC) = 0.905, 95% CI 0.832-0.977). The classifier based on the identified 22 biomarkers also performed well in the cohort from Hong Kong (AUC = 0.811, 95% CI 0.715-0.907) and French (AUC = 0.859, 95% CI 0.773-0.944) populations. Quantitative PCR was applied for measuring three selected biomarkers in the classification of CRC patients in independent Chongqing population containing 30 cases and 30 controls and the best biomarker from Coprobacillus performed well with high AUC (0.930, 95% CI 0.904-0.955). This study revealed increased sensitivity and applicability of our GM biomarkers compared with previous biomarkers significantly promoting the early diagnosis of CRC.

The long-term clinical outcomes of robotic gastrectomy for gastric cancer: a large-scale single institutional retrospective study.

BACKGROUNDS AND PURPOSE: Robotic surgery has been applied in gastric carcinoma over a decade. Although a series of studies were performed to investigate the short-term outcomes of robot-assisted gastrectomy, few papers were in view of long-term outcomes. The current study was aimed to explore the oncological outcomes of robotic gastrectomy for gastric cancer patients. METHODS: A total of 606 gastric cancer patients who underwent robot-assisted gastrectomy during March 2010 through March 2017, were enrolled in this research. The clinicopathologic characteristics, surgical procedures along with follow-up information and prognostic factors were recorded in detail. The disease-free survival and overall survival rates were tested by Kaplan-Meier analysis. RESULTS: All the patients underwent the robotic surgery including 15 proximal gastrectomies, 403 distal gastrectomies, 169 total gastrectomies and 19 remnant gastrectomies. Fifiy-six (9.24%) patients were lost in the follow-up process (3-87 months, a media of 42 months). There were 119 recurrences observed, including 55 local recurrences, 51 peritoneal metastasis and 13 distant metastasis. The 3-year disease-free survival and overall survival were 73.60% and 74.24%, while the 5-year disease-free survivorship and overall survival rates were 68.73% and 69.33%. The 5-year overall survival rates grouped based on TNM stage were 96.58% for IA, 88.16% for IB, 87.03% for IIA, 80.62% fo IIB, 58.50% for IIIA, 48.62% for IIIB, 45.32% for IIIC and 17.03% for IV. CONCLUSION: Robot-assisted gastrectomy is a valuable procedure for gastric cancer patients. Beside its feasibility and safety, it reveals an acceptable long-term clinical outcome.

Interleukin-23 promotes the migration and invasion of gastric cancer cells by inducing epithelial-to-mesenchymal transition via the STAT3 pathway.

Chronic inflammation is associated with all stages of cancer development. Moreover, a proinflammatory microenvironment resulted from chronic inflammation is considered to be an essential component of cancer. Interleukin-23 (IL-23) is a general proinflammatory factor; and is involved in tumor-associated inflammation in gastric cancer (GC). However, the direct effect of IL-23 on GC cells has been rarely reported. The aim of the study was to clarify the direct role of IL-23 in regulating GC progression, and to identify the underlying mechanism. In this study, Positive expression of IL-23R was observed in GC tissues and cell lines by using immunohistochemistry or immunofluorescence. In western blots, the expression of IL-23R was higher in GC tissues compared with adjacent normal tissues. Furthermore, IL-23R positive GC tissues were closely related with larger tumor size and worse T stage and clinical stage. By performing in vitro experiments, we found that IL-23 binding to its receptor promoted the migration and invasion of BGC-823 cells in vitro. Moreover, IL-23 induced the activation of STAT3 and epithelial-to-mesenchymal transition (EMT) in BGC-823 cells. Knocking down STAT3 in BGC-823 cells attenuated the effect of IL-23 on EMT and cell migration and invasion. Taken together, our study has firstly demonstrated the positive expression of IL-23R in human GC tissues and cell lines. IL-23 binding to its receptor promotes the migration and invasion of GC cells by inducing EMT through the STAT3 signaling pathway. This work provides a new mechanism for the oncogenic role of IL-23 on GC progression.

HIF-1α induces the epithelial-mesenchymal transition in gastric cancer stem cells through the Snail pathway.

Substantial evidence suggests that the epithelial-mesenchymal transition (EMT) phenotype is associated with the invasive characteristics of cancer stem cells (CSCs),which possess an EMT phenotype that may predominate in tumor invasion and metastasis. However, the mechanisms for the generation and regulation of these CSCs have not been clearly defined. As hypoxia and EMT-related factors may have important functions in EMT-like CSCs, the aim of this study was to investigate the effects of hypoxia on these cells. CSCs were established from the gastric cancer cell lines MGC-803 and SGC7901, and the relationship between hypoxia and EMT-like CSCs was investigated in gastric cancer. After hypoxia treatment, some gastric CSCs exhibited a marked increase in hypoxia-inducible factor-1α (HIF-1α)expression and increased migration and invasion capabilities compared with the normoxic control. These CSCs were defined by activation of the mesenchymal cell marker Vimentin and by inhibition of the epithelial cell marker E-cadherin. Our analyses also show that HIF-1α was responsible for activating EMT via increased expression of the transcription factor Snail in gastric CSCs. Moreover, inhibition of Snail by shRNA reduced HIF-1α-induced EMT in gastric CSCs. The results demonstrated that hypoxia-induced EMT-like CSCs rely on HIF-1αto activate Snail, which may result in recurrence and metastasis of gastric cancer.

Increased chemokine receptor IL-17RA expression is associated with poor survival in gastric cancer patients.

BACKGROUND: Previous researchers have identified that the chemokine interleukin-17 (IL-17) was associated with survival time of patients with gastric cancer, but the roles of its receptors (IL-17R) in gastric cancer remain unknown. Our studies were designed to clarify the function of IL-17RA and to explore their potential role in gastric cancer. MATERIALS AND METHODS: The expression of IL-17RA was determined in primary gastric cancer tissues (n=101) using Real-time RT-PCR, immunohistochemistry, and western blotting. To investigate the functional significance of IL-17RA expression, IL-17RA expression and clinical parameters, multivariate survival was analyzed in patients with gastric cancer. RESULTS: IL-17RA was overexpression in gastric cancer tissues compared with adjacent normal tissues (P<0.05). The elevated expression level of IL-17RA was observed correlated significantly with tumor progression (P=0.003), Lymphatic invasion (P=0.019), lymphoid nodal status (P=0.001), distant metastasis (P<0.001) of gastric cancer patients, TNM stage (P=0.0013) and was one of the independent prognostic factors for patient's overall survival. CONCLUSIONS: These results demonstrated that the expression of IL-17RA plays an important role in gastric cancer progression, migration and prognosis of gastric cancer. The IL-17-IL-17RA signaling mechanism may be a potential novel target.