Dissemination of free cancer cells from the gastric lumen and from perigastric lymphovascular pedicles during radical gastric cancer surgery

Novel nomogram and risk stratification for peritoneal recurrence after curative resection in gastric cancer

Peritoneal recurrence (PR) in gastric cancer after curative resection has poor prognosis. Therefore, we aimed to construct a nomogram to predict PR, and establish PR score for risk stratification to guide adjuvant chemotherapy. A total of 315 patients with gastric cancer after radical surgery were included, and randomly stratified into training group (n = 221) and validation group (n = 94). Univariate and multivariate analyses were used to determine predictive factors of PR. The nomogram was constructed to predict the risk of PR. We utilized the time-dependent area under the receiver operating characteristic (ROC) curves (AUCs), calibration curves, and decision curve analysis (DCA) to evaluate the performance of the nomogram. Multivariate analysis showed that tumor site, N stage, preoperative CEA, and postoperative CA199 were independent predictors of PR. A nomogram was constructed to predict PR based on these factors. The AUC value was 0.755 in the training group and 0.715 in the validation group. The calibration curves showed good agreement between prediction and observation in the training and validation groups. The decision curve analysis displayed a good net benefit of the nomogram. The novel PR score was developed and patients were stratified into the low-, medium-, and high -risk groups. For the high-risk group, postoperative adjuvant chemotherapy significantly improved patients' overall survival (OS) and disease-free survival (DFS). The establishment of nomogram facilitates the prediction of PR after radical gastrectomy, and a novel PR score may help guide adjuvant chemotherapy for gastric cancer.

Comparison of Peritoneal Cytology Results Before and After Resection in Gastric Cancer Patients

OBJECTIVE

Peritoneal cytology is used to detect the peritoneal spread of gastric cancer and to assess survival rate. The aim of this study was to compare the risk factors, recurrence, and survival of gastric cancer patients with positive and negative peritoneal cytology before and after resection.

MATERIALS AND METHODS

Patients with gastric cancer who underwent elective surgery were retrospectively analysed. The study covered a period between September 2018 and September 2020. After applying the exclusion criteria, 57 patients were included in the study. For the purpose of this study, peritoneal cytology was taken from the same three intra-abdominal regions before and after resection from patients with operable gastric cancer.

RESULTS

Of the 57 patients included in the study, 36 (63.2%) were male patients and 21 (36.8%) were female patients. Preoperative or postoperative malignant cytology was detected in 12 patients (21.1%). Tumour diameter was larger in patients with preoperatively detected malignant cytology than in the patients with postoperatively positive malignant cytology (66.67 mm vs. 44.44 mm) (p = 0.006). The recurrence rate was higher in patients with preoperative and postoperative positive cytology than in those with negative cytology (p = 0.019). The survival of patients with preoperative malignant cytology was worse than the survival of patients with preoperative benign cytology (p = 0.011). A significant correlation was found between lymphovascular invasion (+), perineural invasion (+), T4, Stage 3 disease, number of malignant lymph nodes, and preoperative cytology positivity (p <0.05).

CONCLUSION

In our study, we found that the preoperative cytology positivity is associated with lymphovascular invasion positivity, perineural invasion positivity, T4 tumour, Stage 3 disease, and the number of malignant lymph nodes. Postoperative positive cytology was not associated with the same variables. Because of the significant associations in preoperative positivity, fluid samples should be obtained immediately after the abdomen is open and before the tumour is manipulated. If possible, fluid samples should be taken from different quadrants, but if the sample is to be taken from a single quadrant, it should be taken from the pelvis.

Long-term survival outcomes of robotic total gastrectomy for locally advanced proximal gastric cancer: a prospective study

BACKGROUND

Robotic gastrectomy is a safe and feasible approach for gastric cancer (GC); however, its long-term oncological efficacy remains unclear. The authors evaluated the long-term survival outcomes and recurrence patterns of patients with locally advanced proximal GC who underwent robotic total gastrectomy (RTG).

METHODS

This prospective study (FUGES-014 study) enrolled 48 patients with locally advanced proximal GC who underwent RTG between March 2018 and February 2020 at a tertiary referral teaching hospital. Patients who underwent laparoscopic total gastrectomy (LTG) in the FUGES-002 study were enrolled in a 2:1 ratio to compare the survival outcomes between RTG and LTG. The primary endpoint of the FUGES-014 study was postoperative 30-day morbidity and has been previously reported. Here, the authors reported the results of 3-year disease-free survival (DFS), 3-year overall survival (OS), and recurrence patterns.

RESULTS

After propensity score matching, 48 patients in the RTG and 96 patients in the LTG groups were included. The 3-year DFS rates were 77.1% (95% CI: 66.1-89.9%) for the RTG and 68.8% (95% CI: 60.1-78.7%) for the LTG groups ( P =0.261). The 3-year OS rates were not significantly different between the groups (85.4 vs. 74.0%, P =0.122). Recurrence occurred in nine patients (18.8%) in the RTG and 27 (28.1%) patients in the LTG groups ( P =0.234). Recurrence patterns and causes of death were similar between the groups ( P >0.05).

CONCLUSIONS

The oncological outcome of RTG was noninferior to that of LTG. Thus, RTG might be an alternative surgical treatment for locally advanced proximal GC.

Robotic versus laparoscopic distal gastrectomy for resectable gastric cancer: a randomized phase 2 trial

Robotic surgery may be an alternative to laparoscopic surgery for gastric cancer (GC). However, randomized controlled trials (RCTs) reporting the differences in survival between these two approaches are currently lacking. From September 2017 to January 2020, 300 patients with cT1-4a and N0/+ were enrolled and randomized to either the robotic (RDG) or laparoscopic distal gastrectomy (LDG) group (NCT03313700). The primary endpoint was 3-year disease-free survival (DFS); secondary endpoints reported here are the 3-year overall survival (OS) and recurrence patterns. The remaining secondary outcomes include intraoperative outcomes, postoperative recovery, quality of lymphadenectomy, and cost differences, which have previously been reported. There were 283 patients in the modified intention-to-treat analysis (RDG group: n = 141; LDG group: n = 142). The trial has met pre-specified endpoints. The 3-year DFS rates were 85.8% and 73.2% in the RDG and LDG groups, respectively (p = 0.011). Multivariable Cox regression model including age, tumor size, sex, ECOG PS, lymphovascular invasion, histology, pT stage, and pN stage showed that RDG was associated with better 3-year DFS (HR: 0.541; 95% CI: 0.314-0.932). The RDG also improved the 3-year cumulative recurrence rate (RDG vs. LDG: 12.1% vs. 21.1%; HR: 0.546, 95% CI: 0.302-0.990). Compared to LDG, RDG demonstrated non-inferiority in 3-year DFS rate.

Efficacy and Safety of Extensive Intraperitoneal Lavage for Patients with Gastric Cancer - A Systematic Review and Meta-analysis

PURPOSE

Extensive  intraperitoneal lavage (EIPL) is a novel therapeutic intervention that aims to limit the chance of peritoneal metastasis during gastrectomy. Clinical trials on using EIPL after gastrectomy show controversial results. We aimed to summarize the evidence of efficacy and safety for using EIPL after gastrectomy to limit the possibility of peritoneal metastasis and improve survival.

METHODS

A literature search on PubMed, Scopus, Embase, and Web of Sciences was conducted till June 2023 to identify eligible RCTs that assess the efficacy and safety of EIPL after gastrectomy. The hazard ratio with 95% CI was used to determine the survival probability, the risk ratio with 95% CI was used to assess the surgical outcomes, and ROB-2 and GRADE guidelines were used to assess the risk of bias and the certainty of evidence respectively.

RESULTS

Six eligible studies with a total of 1993 patients were included in the meta-analysis. Regarding survival benefits, the survival of the EIPL group did not differ significantly from the non-EIPL group, and the pooled HR of overall survival was 0.86 (95% CI 0.58-1.26) P = 0.44, the disease-free survival was 0.81 (0.58-1.13) P = 0.21, and peritoneal recurrence-free survival was 0.97 (0.79-1.2) P = 0.25. There is no significant association between EIPL and short-term postoperative outcomes. The use of EIPL does not appear to affect postoperative mortality, infection, anastomotic leakage, bleeding, ileus, or hospital stay.

CONCLUSION

Our study yielded insufficient evidence about the survival benefits and surgical outcomes of EIPL in patients with gastric cancer after gastrectomy. Therefore, it is not recommended for treating gastric cancer patients.

Intragastric free cancer cells may be attached to automatic staplers during anastomosis in patients with gastric cancer

BACKGROUND

Automatic staplers are often used to reconstruct the digestive tract during surgeries for gastric cancer. Intragastric free cancer cells adhering to automatic staplers may come in contact with the laparoscopic port area and progress to port site recurrence. This study aimed to investigate the presence/absence of cancer cells adhering to automatic staplers during gastric cancer surgery using cytological examinations. We further determined the positive predictive clinicopathological factors and clinical implications of free cancer cells attached to automatic staplers.

METHODS

This study included 101 patients who underwent distal gastrectomy for gastric cancer. Automatic staplers used for anastomosis in gastric cancer surgeries were shaken in 150 ml of saline solution to collect the attached cells. Papanicolaou stains were performed. We tested the correlation between cancer-cell positivity and clinicopathological factors to identify risk factors arising from the presence of attached cancer cells to the staplers.

RESULTS

Based on the cytology, cancer cells were detected in 7 of 101 (6.9%) stapler washing fluid samples. Univariate analysis revealed that circular staplers, type 1 tumors, and positive lymph nodes were significantly associated with higher detection of free cancer cells adhering to staplers. No significant differences in other factors were detected. Of the seven cases with positive cytology, one developed anastomotic recurrence.

CONCLUSIONS

Exfoliated cancer cells adhered to the automatic staplers used for anastomoses in 6.9% of the staplers used for distal gastrectomies in patients with gastric cancer. Staplers used for gastric cancer surgeries should be handled carefully.

Indocyanine green fluorescence imaging-guided versus conventional laparoscopic lymphadenectomy for gastric cancer: long-term outcomes of a phase 3 randomised clinical trial

Indocyanine green (ICG) fluorescence imaging-guided lymphadenectomy has been demonstrated to be effective in increasing the number of lymph nodes (LNs) retrieved in laparoscopic gastrectomy for gastric cancer (GC). Previously, we reported the primary outcomes and short-term secondary outcomes of a phase 3, open-label, randomized clinical trial (NCT03050879) investigating the use of ICG for image-guided lymphadenectomy in patients with potentially resectable GC. Patients were randomly (1:1 ratio) assigned to either the ICG or non-ICG group. The primary outcome was the number of LNs retrieved and has been reported. Here, we report the primary outcome and long-term secondary outcomes including three-year overall survival (OS), three-year disease-free survival (DFS), and recurrence patterns. The per-protocol analysis set population is used for all analyses (258 patients, ICG [n = 129] vs. non-ICG group [n = 129]). The mean total LNs retrieved in the ICG group significantly exceeds that in the non-ICG group (50.5 ± 15.9 vs 42.0 ± 10.3, P < 0.001). Both OS and DFS in the ICG group are significantly better than that in the non-ICG group (log-rank P = 0.015; log-rank P = 0.012, respectively). There is a difference in the overall recurrence rates between the ICG and non-ICG groups (17.8% vs 31.0%). Compared with conventional lymphadenectomy, ICG guided laparoscopic lymphadenectomy is safe and effective in prolonging survival among patients with resectable GC.

Infrapyloric (No. 206) and greater curvature (No. 204) lymph node metastasis in adenocarcinoma located in the right half of the transverse colon (InCLART Study): protocol for a multicentre prospective observational study

INTRODUCTION

In the case of right-sided transverse colon cancer (RTCC) and hepatic flexure colon cancer (HFCC), there is a potential connection of lymph drainage between mesentery and greater omentum. However, most previous reports have been limited case series with No. 206 and No. 204 lymph node (LN) dissection for RTCC and HFCC.

METHODS AND ANALYSIS

The InCLART Study is a prospective observational study aiming to enrol 427 patients with RTCC and HFCC treated at 21 high-volume institutions in China. The prevalence of infrapyloric (No. 206) and greater curvature (No. 204) LN metastasis and short-term outcomes will be investigated in a consecutive series of patients with T2 or deeper invasion RTCC or HFCC, following the principle of complete mesocolic excision with central vascular ligation. Primary endpoints were performed to identify the prevalence of No. 206 and No. 204 LN metastasis. Secondary analyses will be used to estimate prognostic outcomes, intraoperative and postoperative complications, the consistency of preoperative evaluation and postoperative pathological results of LN metastasis.

ETHICS AND DISSEMINATION

Ethical approval for the study has been granted by the Ruijin Hospital Ethics Committee (approval number: 2019-081) and has been or will be approved successively by each participating centre's Research Ethics Board. The findings will be disseminated in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03936530; https://clinicaltrials.gov/ct2/show/NCT03936530).

Pure endoscopic resection versus laparoscopic assisted procedure for upper gastrointestinal stromal tumors: Perspective from a surgical endoscopist

Management of upper gastrointestinal (UGI) tract gastrointestinal stromal tumor (GIST) has evolved significantly over the past two decades. For GIST size smaller than 5 cm, laparoscopic resection has become the current standard. To avoid postoperative gastric deformity and preserve gastric function, laparoscopic endoscopic cooperative surgery (LECS) was developed and various modifications have been reported and utilized successfully. Pure endoscopic resection techniques have also been reported at a similar period of time, which further push the boundary of incisionless surgery in managing these lesions. Both tunneling and nontunneling exposed type endoscopic full thickness resection are well described procedures for resection of small UGI GIST. In this review, a summary of these procedures is provided, and the pros and cons of each technique from the perspective of a surgical endoscopist are discussed in detail. LECS and endoscopic resection are complementary to each other. The choice of technique should be tailored to the location, morphology, and size of the target lesions, taking into account the experience of the laparoscopic surgeons and endoscopists.

Role of prophylactic HIPEC in non-metastatic, serosa-invasive gastric cancer: a literature review

The role of prophylactic hyperthermic intraperitoneal chemotherapy (p-HIPEC) in serosa invasive gastric cancers without gross or microscopic peritoneal disease, to reduce the rate of peritoneal relapse is an area of ongoing research. Although p-HIPEC is effective in reducing the rate of peritoneal relapse and improving disease free and overall survival with or without adjuvant chemotherapy, when added to curative surgery in locally advanced, non-metastatic gastric cancers, the available literature is at best, heterogeneous, centre-specific and skewed. Apart from that, variations in the systemic therapy used, and the presence of the associated nodal disease further complicate this picture. To evaluate the role of p-HIPEC the PubMed, Cochrane central register of clinical trials, and the American Society of Clinical Oncology (ASCO) meeting library were searched with the search terms, “gastric”, “cancer”, “hyperthermic”, “intraperitoneal”, “chemotherapy”, prophylactic”, “HIPEC” in various combinations, and a critical review of the available evidence was done. Although p-HIPEC is a promising therapy in the management of locally advanced gastric cancers, the current evidence is insufficient to recommend its inclusion into routine clinical practice. Future research should be directed towards identification of the appropriate patient subset and towards redefining its role with current peri-operative systemic therapies.

Intracorporeal hand-sewn anastomosis following pylorus-preserving gastrectomy: surgical technique and short-term surgical outcome

BACKGROUND

Although several procedures for mechanical anastomosis have recently been reported, intracorporeal manually hand-sewn anastomosis for totally laparoscopic pylorus-preserving gastrectomy (TLPPG) is considered technically difficult. Here, we report a new technique for laparoscopic reconstruction using hand-sewn sutures.

METHODS

Together with a proper lymphadenectomy, the stomach was detached and resected using separate two-layer incisions, similar to the original laparotomy method. An approximately 5-cm antral cuff was left in place. The essential concept of this new method was to align the anastomotic site by rotating each clamped gastric stump. This allowed us to perform a secure, hand-sewn, two-layer anastomosis successfully. The short-term surgical outcome after TLPPG was retrospectively compared with that for patients who underwent a conventional laparoscopy-assisted procedure (LAPPG).

RESULTS

Of the 20 consecutive patients who underwent pylorus-preserving gastrectomy in our department between 2014 and 2021, the first 8 patients and the subsequent 12 patients underwent LAPPG and TLPPG, respectively. The operation time was significantly longer in the TLPPG group (median, 302 vs. 269 min). The morbidity was comparable (8.3% in TLPPG vs. 12.5% in LAPPG). Postoperative delayed gastric emptying was only observed in one patient in the LAPPG group. TLPPG reduced the cost of the operation by reducing the number of linear stapler cartridges required.

CONCLUSION

A purely hand-sewn gastrogastrostomy is safe, feasible, and cost-effective, and it omits the need for a mini-laparotomy in the upper abdomen.

Hyperthermic Intraperitoneal Chemotherapy (HIPEC) Combined with Surgery: A 12-Year Meta-Analysis of this Promising Treatment Strategy for Advanced Gastric Cancer at Different Stages

BACKGROUND

This meta-analysis was designed to systematically assess the effectiveness and safety of hyperthermic intraperitoneal chemotherapy (HIPEC) combined with surgery for different stages of advanced gastric cancer (AGC) during the last 12 years.

METHODS

The Cochrane Library, PubMed, Embase, Web of Science, and China National Knowledge Infrastructure (CNKI) were searched online, and papers were retrieved from other sources. Next, randomized controlled trials (RCTs) and high-quality nonrandomized controlled trials (NRCTs) were selected for this analysis. The meta-analysis was conducted with RevMan5.4 software.

RESULT

The 10 RCTs and 13 NRCTs selected for the study included 1892 patients. The overall survival rates were higher in the HIPEC group at 1 year (risk ratio [RR], 0.52; P = 0.004) and 3 years (RR, 0.63; P < 0.00001) than in the control group for the patients without peritoneal cancer, and the HIPEC group had a significant reduction in the recurrence rate (RR, 0.60; p < 0.00001). Among the patients with peritoneal carcinomatosis (PC), the HIPEC group had significantly higher overall survival rates at 1 year (RR, 0.62; P = 0.00001), 2 years (RR, 0.85; P = 0.002), and 3 years (RR, 0.87; P = 0.0001), with an increase in the overall median survival time of 4.67 months. The two groups showed no statistically significant difference in terms of complications for patients with PC (RR, 1.03; P = 0.93) or without PC (RR, 1.15; P = 0.51).

CONCLUSION

For local AGC without PC, standard surgery combined with prophylactic HIPEC could prolong survival and reduce the recurrence rate without more complications. The prognosis of this treatment strategy for patients with PC is closely related to patient selection. Complete cytoreduction combined with therapeutic HIPEC could prolong survival.

Three-year outcomes of the randomized phase III SEIPLUS trial of extensive intraoperative peritoneal lavage for locally advanced gastric cancer

Whether extensive intraoperative peritoneal lavage (EIPL) after gastrectomy is beneficial to patients with locally advanced gastric cancer (AGC) is not clear. This phase 3, multicenter, parallel-group, prospective randomized study (NCT02745509) recruits patients between April 2016 and November 2017. Eligible patients who had been histologically proven AGC with T3/4NxM0 stage are randomly assigned (1:1) to either surgery alone or surgery plus EIPL. The results of the two groups are analyzed in the intent-to-treat population. A total of 662 patients with AGC (329 patients in the surgery alone group, and 333 in the surgery plus EIPL group) are included in the study. The primary endpoint is 3-year overall survival (OS). The secondary endpoints include 3-year disease free survival (DFS), 3-year peritoneal recurrence-free survival (reported in this manuscript) and 30-day postoperative complication and mortality (previously reported). The trial meets pre-specified endpoints. Estimated 3-year OS rates are 68.5% in the surgery alone group and 70.6% in the surgery plus EIPL group (log-rank p = 0.77). 3-year DFS rates are 61.2% in the surgery alone group and 66.0% in the surgery plus EIPL group (log-rank p = 0.24). The pattern of disease recurrence is similar in the two groups. In conclusion, EIPL does not improve the 3-year survival rate in AGC patients.

Molecular Cytology by One-Step Nucleic Acid Amplification (OSNA) Assay of Peritoneal Washings during D2 Gastrectomy in Advanced Gastric Cancer Patients: Preliminary Results

The presence of peritoneal free cancer cells (FCC) in gastric cancer (GC) patients is a poor prognostic factor. D2 gastrectomy may induce exfoliated FCC spread from the primary tumour or involved lymph nodes (LN). Conventional cytology for FCC detection has several limitations, whereas prophylactic use of extensive intraoperative peritoneal lavage (IPL) does not improve survival. A prospective single-arm observational study was conducted to verify whether D2 gastrectomy causes an intraoperative increase of FCC in peritoneal fluid. Twenty-seven GC patients underwent D2 gastrectomy, followed by objective quantitative measurements of CK19 mRNA level reflecting FCC with One-Step Nucleic Acid Amplification (OSNA) assay. The IPL with 3000 mL of saline was performed twice: (1) after gastrectomy with D2 lymphadenectomy and (2) after alimentary tract reconstruction. The IPL samples were analysed by initial cytology and four (1-4) consecutive OSNA assays. Initial OSNA measurement (1) revealed positive results (≥24.6 cCP/μL) in 7 (29.6%) patients. Subsequent OSNA measurements showed a significant decrease in the FCC level after D2 gastrectomy (1 vs. 2; p = 0.0012). The first IPL induced a non-significant increase in the FCCs (2 vs. 3, p = 0.3300), but the second IPL reversed it to normal levels (3 vs. 4, p = 0.0.0574). The OSNA assay indicates a temporal intraoperative increase in the peritoneal FCC in advanced GC patients undergoing D2 gastrectomy. Two consecutive IPLs are necessary to reverse the increase of CK19 mRNA level in peritoneal washings.

Clinical implications of Indocyanine Green Fluorescence Imaging-Guided laparoscopic lymphadenectomy for patients with gastric cancer: A cohort study from two randomized, controlled trials using individual patient data

BACKGROUND

The value of indocyanine green (ICG) fluorescence imaging in tracing metastatic lymph nodes (LNs) has rarely been reported. We aimed to evaluate the clinical implications of fluorescence imaging-guided lymphadenectomy and the sensitivity of fluorescent lymphography to detect metastatic LN stations in gastric cancer (GC).

MATERIALS AND METHODS

This analysis pooled data from two randomized controlled trials (FUGES-012 and FUGES-019 studies) on laparoscopic ICG tracer-guided lymphadenectomy for GC between November 2018 and October 2020. Patients who received ICG injection using either the intraoperative subserosal or preoperative submucosal approaches 1 day before surgery and underwent fluorescence imaging-guided lymphadenectomy were defined as the ICG group. Patients who underwent conventional lymphadenectomy without ICG injection and intraoperative imaging were defined as the non-ICG group.

RESULTS

Among 514 enrolled patients, the ICG and non-ICG groups included 385 and 129, respectively. A significantly higher mean number of LNs was retrieved in the ICG group than in the non-ICG group (49.9 vs. 42.0, P < 0.001). The ICG group showed a lower LN noncompliance rate than that in the non-ICG group (31.9% vs. 57.4%, P < 0.001). The sensitivity of fluorescence imaging for detecting all metastatic LN stations was 86.8%. The negative predictive value was 92.2% for nonfluorescent stations. For detecting all metastatic stations, subgroup analysis revealed 97.7%, 91.7%, 86.2%, and 84.3% sensitivities for pT1, pT2, pT3, and pT4a tumors, respectively. Regardless of gastrectomy type, the diagnostic accuracy for detecting all metastatic stations in the D1+ and D2 stations for cT1-cT2 disease reached 100%.

CONCLUSION

ICG fluorescence imaging, using either the subserosal or submucosal approaches, assisted in the thorough dissection of potentially metastatic LNs, as recommended for individualized laparoscopic lymphadenectomy for GC.

Does Extended Intraoperative Peritoneal Lavage Really Bring Benefit on Patients With Gastric Cancer? A Meta-Analysis of Published Clinical Trials

Purpose

The purpose of the current meta-analysis is to analyze whether extended intraoperative peritoneal lavage (EIPL) can bring benefit on short-term outcomes or survival for patients undergoing curative gastrectomy for gastric cancer.

Methods

The PubMed, Embase, and Cochrane Library databases were searched from inception to May 3, 2021, to find eligible studies. Postoperative complications, overall survival (OS), disease-free survival (DFS), and peritoneal recurrence-free survival (PRFS) were compared between EIPL group and No EIPL group.

Results

A total of five randomized controlled trials with 1,790 patients were included in the current meta-analysis. No difference was found in baseline information (p > 0.05). After pooling up the data of overall postoperative complications, no significant difference was found between EIPL group and No EIPL group (OR = 0.88, 95% CI = 0.51 to 1.53, P = 0.65). Furthermore, there was no significant difference between EIPL group and No EIPL group in terms of OS (HR = 0.77, 95% CI = 0.36 to 1.64, P = 0.49), DFS (HR = 0.97, 95% CI = 0.71 to 1.33, P = 0.87), and PRFS (HR = 1.03, 95% CI = 0.74 to 1.43, P = 0.86). In terms of subgroup analysis of OS, no significant difference was found as well (HR = 1.05, 95% CI = 0.82 to 1.34, P = 0.69).

Conclusions

EIPL did not bring benefit in terms of short-term outcomes or survival. Therefore, EIPL is not recommended for patients undergoing curative gastrectomy for gastric cancer.

Intraperitoneal Chemotherapy Using Fluorouracil Implants Combined With Radical Resection and Postoperative Adjuvant Chemotherapy for Stage III Gastric Cancer: A Multi-Center, Randomized, Open-Label, Controlled Clinical Study

Background

Reducing peritoneal recurrence after radical surgery is an important choice to improve the prognosis of patients with advanced gastric cancer. Intraoperative intraperitoneal chemotherapy has the potential to be a promising treatment strategy. In the present study, we conducted a multi-center, randomized, controlled clinical study to evaluate the efficacy and safety of intraoperative intraperitoneal chemotherapy using sustained-release fluorouracil implants plus radical gastrectomy and adjuvant chemotherapy for cTNM stage III gastric cancer.

Methods

The patients were randomized into intraperitoneal chemotherapy group (sustained-release fluorouracil implants administration after standard D2 radical gastrectomy, and followed by XELOX adjuvant chemotherapy) and control group (standard D2 radical gastrectomy, and followed by XELOX adjuvant chemotherapy). A total of 122 patients from three centers were enrolled from September 2015 to February 2017.

Results

One hundred and two eligible patients completed the treatment course. The median follow-up time was 41.7 months (36.1–52.9 months). The 3-year progression-free survival rate and overall survival of patients in the intraperitoneal chemotherapy group were 43.9% and 49.1%, respectively, which were significantly better than those of the control group, 31.0% and 38.4%. In the intraperitoneal chemotherapy group, the number of cases with peritoneal recurrence was significantly less than that of the control group, 9 cases (17.3%) vs. 19 cases (44.2%). There were neither significant differences between the groups in the incidence of hematogenous metastasis, lymph node metastasis, nor local metastasis.

Conclusion

For cTNM stage III gastric cancer, intraoperative sustained-release fluorouracil implants after radical resection combined with postoperative adjuvant chemotherapy, could significantly reduce the risk of peritoneal recurrence and prolong PFS.

The benefits of surgery plus extensive intraoperative peritoneal lavage (EIPL) for patients with gastric cancer compared with surgery alone: a systematic review and meta-analysis

This study aims to synthesize the benefits of surgery plus extensive intraoperative peritoneal lavage (EIPL) for patients with gastric cancer compared with surgery alone. We searched Pubmed, Embase, Web of Science, Cochrane library, ClinicalTrials.gov and World Health Organization International Clinical Trials Registry Platform (ICTRP) for randomized controlled trials from 2000 to 2021 according to the inclusion and exclusion criteria. The reference lists of studies meeting the criteria were also screened for additional studies. The quality of these studies was assessed by the Cochrane Collaboration Risk of Bias Tool. An inverse-variance random-effects model of DerSimonian and Laird was used to synthesize the HRs and corresponding 95% CIs of short-term outcomes: hospital mortality and postoperative complications. For long-term outcomes (peritoneal recurrence and 3-year or 5-year overall survival rate), narrative synthesis was used. 4 of 43 studies were included for quantitative analysis. For short-term outcomes, the pooled HRs of hospital mortality and postoperative complications are 0.422 (95%CI: 0.037, 4.790) and 0.774 (95%CI: 0.376, 1.592). For long-term outcomes, despite the inconsistent results, patients receiving EPIL did not have reduced peritoneal recurrence and 3-year or 5-year overall survival rate. Compared with surgery alone, surgery plus EIPL does not have more benefits for patients with gastric cancer.

Long-term prognosis of patients with cancer-related genes detected in postoperative peritoneal washings obtained during curative gastrectomy

BACKGROUND

Cancer cells in intraoperative peritoneal washings (PW) indicate increased peritoneal recurrence. Detection of CEA or CK20 genes indicates poor prognosis. We assessed long-term prognosis of patients with amplification of cancer-related genes in PW obtained intraoperatively during curative gastric cancer surgery.

METHODS

PW was collected before and immediately after curative gastrectomy. CEA, CK20, TFF1, MUC2, and FABP1-mRNA were selected as marker genes for reverse transcription polymerase chain reaction. Peritoneal recurrence-free survival (PRFS) and overall survival (OS) after >7-year follow-up were examined using the Kaplan-Meier method.

RESULTS

Of 138 patients who underwent gastrectomy with negative cytological findings at laparotomy, 80 patients showed negative cancer-related gene amplification in preoperative PW. Fifty-eight patients were excluded due to positive gene amplification, which suggested presence of preoperative peritoneal cancer cells. The 80 patients had mRNA amplification in PW after surgery. Amplification of multiple and single cancer-related marker genes was observed in 38 and 21 patients; 21 cases had marker-negative results. Five-year PRFS was 69.1%, 95.2%, and 100% in multi-marker-positive, single marker-positive, and marker-negative cases, respectively. Multi-marker-positive patients had significantly worse PRFS than the other groups (p < 0.05). Multivariate analysis in the Cox proportional hazards model identified multi-marker-positivity as an independent prognostic factor for PRFS (hazard ratio, 7.6; 95% confidence interval, 1.07-62.63; p = 0.046), and multi-marker-positive patients had significantly worse OS than other groups (p < 0.01).

CONCLUSION

Multi-marker cancer-related gene amplification in PW is associated with worse prognosis in PRFS and OS even after a long follow-up; PRFS can be stratified by the number of genes amplified.

Assessment of Robotic Versus Laparoscopic Distal Gastrectomy for Gastric Cancer: A Randomized Controlled Trial

OBJECTIVE

To evaluate the short-term outcomes of patients with GC who received RDG or LDG.

SUMMARY BACKGROUND DATA

Despite the increasing use of RDG in patients with GC, its safety and efficacy compared to those of LDG have not been elucidated in a randomized controlled trial.

METHODS

Three hundred patients with cT1-4a and N0/+ between September 2017 and January 2020 were enrolled in this randomized controlled trial at a high-volume hospital in China. The short-term outcomes were compared between the groups.

RESULTS

The modified intention-to-treat analysis included data from 283 patients (RDG group: n = 141) and (LDG group: n = 142). Patients in the RDG group exhibited faster postoperative recovery, milder inflammatory responses, and reduced postoperative morbidity (9.2% vs 17.6%, respectively, P = 0.039). Higher extraperigastric lymph nodes (LNs) were retrieved in the RDG group (17.6 ± 5.8 vs 15.8 ± 6.6, P = 0.018) with lower noncompliance rate (7.7% vs 16.9%, respectively, P = 0.006). Additionally, patients in the RDG group were more likely to initiate adjuvant chemotherapy earlier [median (interquartile range) postoperative days: 28 (24-32) vs 32 (26-42), P = 0.003]. Although total hospital costs were higher in the robotic group than in the laparoscopic group, the direct cost was lower for RDG than for LDG (all P < 0.001).

CONCLUSIONS

RDG is associated with a lower morbidity rate, faster recovery, milder inflammatory responses, and improved lymphadenectomy. Additionally, faster postoperative recovery in the RDG group enables early initiation of adjuvant chemotherapy. Our results provide evidence for the application of RDG in patients with GC.

Laparoscopic infrapyloric lymph nodes dissection through the right bursa omentalis approach for gastric cancer

BACKGROUND

A complete dissection of infrapyloric lymph nodes is the key to a curative gastrectomy, which can be sometimes technically challenging in laparoscopic surgery.

METHODS

One hundred and eighteen patients with gastric cancer undergoing laparoscopic gastrectomy with D2 lymphadenectomy in which the infrapyloric lymph nodes were dissected through the right bursa omentalis approach were included. The clinicopathologic characteristics and surgical outcomes were analyzed retrospectively.

RESULTS

The laparoscopic gastrectomy with D2 lymphadenectomy was successful in all 118 patients with no open conversion. The mean operation time was 246.6 ± 45.7 min. The mean estimated blood loss was 87.0 ± 35.9 mL. Postoperative complications occurred in 17.8% of the patients, which were treated successfully with conservative therapy or aspiration in all. There were no No.6 lymphadenectomy-associated complications, such as injury of transverse colon, vessels of mesocolon, pancreas or duodenum, no pancreatitis, pancreatic leakage or postoperative hemorrhage. The mean postoperative hospital stay was 9.6 ± 3.7 days. On average, the total lymph nodes harvested were 36.8 ± 12.9, in which the ones from the infrapyloric area were 5.1 ± 3.1.

CONCLUSION

Laparoscopic dissection of infrapyloric lymph nodes through the right bursa omentalis approach seems to be feasible and safe, facilitating a more complete No.6 lymphadenectomy for gastric cancer.

Extended intraoperative peritoneal lavage as prophylactic peritoneal recurrence for locally advanced gastric cancer: a prospective randomized trial

BACKGROUND

To demonstrate whether extensive intraoperative peritoneal lavage (EIPL) could yield better results in overall survival and less recurrence, regardless of peritoneal cytology, compared to standard peritoneal lavage (SPL).

METHODS

A prospective randomised multicenter study including 94 patients (47 per arm) to detect a 20% difference in 3-year overall survival in patients with locally advanced tumours without peritoneal carcinomatosis. Three samples of peritoneal fluid were obtained (at the beginning, the end of procedure and after the assigned peritoneal lavage). Clinicopathological and surgical data were analysed by group. Postoperative complications, location of recurrence and surgical approach were evaluated. Overall survival was calculated by the Kaplan-Meier method and the uni/multivariate analysis for prognostic factors was carried out using Cox regression analysis.

RESULTS

A total of 86 patients were analysed (4 excluded per group). No statistical differences were observed in clinicopathological or surgical data between groups, considering both groups well-balanced for analysis. Overall survival at 3 years was 64.3% for SPL vs. 62.3% for EIPL (p 0.421). Only three patients had at least one positive peritoneal cytology (1:2). There were no differences regarding postoperative complications (SPL: 37.2% vs. EIPL: 32.5%, p 0.65) or between location of recurrence and number of recurrences. The number of recurrences did not differ between surgical approaches, but locoregional and peritoneal recurrences were fewer with the laparoscopic approach (p 0.048).

CONCLUSIONS

The regular use of extensive peritoneal lavage in patients with locally advanced gastric cancer, regardless of peritoneal cytology, has not been effective as prophylaxis of peritoneal recurrence or better survival.

Effects of Laparoscopic Radical Gastrectomy on Peritoneal Micrometastases of Gastric Cancer

BACKGROUND

Some reports asserted that the stimulation of ultrasonic scalpel and the persistent state of carbon dioxide (CO2) pneumoperitoneum in laparoscopic surgery may affect the adhesion and invasion of gastric cancer (GC) cells. This study aimed to reveal the effects of laparoscopic radical gastrectomy on peritoneal micrometastases (PM) of GC.

MATERIALS AND METHODS

Fifty-three patients who underwent laparoscopic radical gastrectomy for GC were enrolled in the study. The expressions of carcinoembryonic antigen (CEA) mRNA and dopa decarboxylase (DDC) mRNA in peritoneal lavage fluid were detected by reverse transcription-polymerase chain reaction. The positive rates of CEA mRNA and DDC mRNA in preoperative peritoneal lavage fluid (pre-CEA, pre-DDC) were compared with those in postoperative lavage fluid (post-CEA, post-DDC). The correlation between the expressions of pre-CEA and pre-DDC and clinicopathologic factors and disease-free survival was analyzed.

RESULTS

There was no significant difference in the positive rates of pre-CEA and pre-DDC compared with those of post-CEA and post-DDC (all P>0.05). The positive rates of pre-CEA and pre-DDC increased with the increase of TNM stage, deepening of invasion, lymph node metastasis, and serosal invasion (all P<0.05), but had no correlation with tumor location, size, degree of differentiation, nerve invasion, and vascular invasion (all P>0.05). The disease-free survival in the combined positive patients was lower than that in the negative patients.

CONCLUSIONS

Laparoscopic radical gastrectomy for GC is safe and feasible, without increasing the risk of PM. The PM of GC may be associated with late tumor stage, deep infiltration, lymph node metastasis, and serosal invasion.

Transrectal laparoscopy using flexible endoscopy with a submucosal tunneling method: Porcine survival model

OBJECTIVES

Transrectal laparoscopy (TRLS) using a flexible endoscope was recently proposed for peritoneal observation. Although previous studies have reported its feasibility, follow-up durations were insufficient to ascertain technical safety. Moreover, knowledge about the technical feasibility of collecting peritoneal cytological lavage or ascites during TRLS is limited. Thus, this study aimed to confirm the safety and efficacy of TRLS in a porcine survival model.

METHODS

After creating artificial ascites in 10 animals, TRLS was performed as follows: submucosal tunnel creation on the anterior wall of the rectum, intentional perforation at the distal end of the tunnel, endoscopic ascites collection and intraperitoneal observation, and clip closure at the mucosal incision site. The pigs were administered antibiotics orally for 7 days after TRLS and killed for histological evaluation and bacterial culture after 28 days of observation.

RESULTS

The technical success rates of insertion into the abdominal cavity, ascites collection, and clip closure were 100%. All frequent anatomical sites for peritoneal dissemination including the stomach, subdiaphragmatic space, and pelvic space were fully observable without adverse events. The median procedure time was 36.3 min. Full 28-day survival was observed in all cases without any infection. The autopsies showed no infection, including abscess formation. Bacterial cultures of the peritoneal cavity were negative 28 days after TRLS in all cases.

CONCLUSIONS

Transrectal laparoscopy enabled ascites collection and intraperitoneal observation without adverse events. All animals survived without peritonitis. Therefore, TRLS can be an option for intraperitoneal examination.

Artificial intelligence: A new budding star in gastric cancer

The pursuit of health has always been the driving force for the advancement of human society, and social development will be profoundly affected by every breakthrough in the medical industry. With the arrival of the information technology revolution era, artificial intelligence (AI) technology has been rapidly developed. AI has been combined with medicine but it has been less studied with gastric cancer (GC). AI is a new budding star in GC, and its contribution to GC is mainly focused on diagnosis and treatment. For early GC, AI’s impact is not only reflected in its high accuracy but also its ability to quickly train primary doctors, improve the diagnosis rate of early GC, and reduce missed cases. At the same time, it will also reduce the possibility of missed diagnosis of advanced GC in cardia. Furthermore, it is used to assist imaging doctors to determine the location of lymph nodes and, more importantly, it can more effectively judge the lymph node metastasis of GC, which is conducive to the prognosis of patients. In surgical treatment of GC, it also has great potential. Robotic surgery is the latest technology in GC surgery. It is a bright star for minimally invasive treatment of GC, and together with laparoscopic surgery, it has become a common treatment for GC. Through machine learning, robotic systems can reduce operator errors and trauma of patients, and can predict the prognosis of GC patients. Throughout the centuries of development of surgery, the history gradually changes from traumatic to minimally invasive. In the future, AI will help GC patients reduce surgical trauma and further improve the efficiency of minimally invasive treatment of GC.

Extensive peritoneal lavage with saline after curative gastrectomy for gastric cancer (EXPEL): a multicentre randomised controlled trial

BACKGROUND

Peritoneal recurrence of gastric cancer after curative surgical resection is common and portends a poor prognosis. Early studies suggest that extensive intraoperative peritoneal lavage (EIPL) might reduce the risk of peritoneal recurrence and improve survival. We aimed to evaluate the survival benefit of EIPL in patients with gastric cancer undergoing curative gastrectomy.

METHODS

In this open-label, phase 3, multicentre randomised trial, patients aged 21-80 years with cT3 or cT4 gastric cancer undergoing curative resection were enrolled at 22 centres from South Korea, China, Japan, Malaysia, Hong Kong, and Singapore. Patients were randomly assigned to receive surgery and EIPL (EIPL group) or surgery alone (standard surgery group) via a web-based programme in random permuted blocks in varying block sizes of four and six, assuming equal allocation between treatment groups. Randomisation was stratified according to study site and the sequence was generated using a computer program and concealed until the interventions were assigned. After surgery in the EIPL group, peritoneal lavage was done with 1 L of warm (42°C) normal 0·9% saline followed by complete aspiration; this procedure was repeated ten times. The primary endpoint was overall survival. All analyses were done assuming intention to treat. This trial is registered with ClinicalTrials.gov, NCT02140034.

FINDINGS

Between Sept 16, 2012, and Aug 3, 2018, 800 patients were randomly assigned to the EIPL group (n=398) or the standard surgery group (n=402). Two patients in the EIPL group and one in the standard surgery group withdrew from the trial immediately after randomisation and were excluded from the intention-to-treat analysis. At the third interim analysis on Aug 28, 2019, the predictive probability of overall survival being significantly higher in the EIPL group was less than 0·5%; therefore, the trial was terminated on the basis of futility. With a median follow-up of 2·4 years (IQR 1·5-3·0), the two groups were similar in terms of overall survival (hazard ratio 1·09 [95% CI 0·78-1·52; p=0·62). 3-year overall survival was 77·0% (95% CI 71·4-81·6) for the EIPL group and 76·7% (71·0-81·5) for the standard surgery group. 60 adverse events were reported in the EIPL group and 41 were reported in the standard surgery group. The most common adverse events included anastomotic leak (ten [3%] of 346 patients in the EIPL group vs six [2%] of 362 patients in the standard surgery group), bleeding (six [2%] vs six [2%]), intra-abdominal abscess (four [1%] vs five [1%]), superficial wound infection (seven [2%] vs one [<1%]), and abnormal liver function (six [2%] vs one [<1%]). Ten of the reported adverse events (eight in the EIPL group and two in the standard surgery group) resulted in death.

INTERPRETATION

EIPL and surgery did not have a survival benefit compared with surgery alone and is not recommended for patients undergoing curative gastrectomy for gastric cancer.

FUNDING

National Medical Research Council, Singapore.

Injured tissues favor cancer cell implantation via fibrin deposits on scar zones

Aim

Evaluation of fibrin role on cancer cells implantation in injured tissues and studying the molecular mechanism of cancer cell interaction with the peritoneal damage.

Material and methods

Mouse colon cancer (CT26) and human mesothelial cells (HMCs) were used. CT26 cells were implanted on injured peritoneal zones. Icodextrin was used as a lubricant. For in vitro studies, fibrin clots from human plasma were used. The cell-fibrin interaction was observed by optical, electronic, and confocal microscopies. Aprotinin was used as a plasmin inhibitor. Hemostasis impact quantified by (1) the fibrin degradation product D-Dimer and PAR expression in HMCs; (2) the expression of plasminogen activator (PA) and its inhibitor (PAI-1) in cancer cells by qPCR and in supernatants through ELISA after in vitro HMC incubation with 2U of thrombin for 24 h.

Results

(i) Cancer cell lines were adhered and implanted into the wound area in vivo in both the incision and peeling zones of the peritoneum and on the fibrin network in vitro. (ii) Icodextrin significantly inhibited cancer nodule formation in the scar and the incision or peritoneal damaged zones after surgery. (iii) In in vitro studies, cancer cell interaction with the fibrin clot generated a lysed area, causing an increase in plasmin-dependent fibrinolysis measured by D-dimer levels in the supernatants that was inhibited by aprotinin. (iv) Aprotinin inhibited cell-fibrin interaction and invasion. (v) Thrombin upregulates PAI-1 and downregulates PA expression in HMC.

Conclusion

Injured tissues favor cancer cell implantation through generated fibrin. Fibrin-cancer cells adhesion can be inhibited by icodextrin.

Combined Analysis of Intragastric Malignant Exfoliation and Ca 72.4 Concentration in Stomach Adenocarcinoma: The "GL1 Ca 72.4" Parameter

INTRODUCTION/OBJECTIVE

Differently from other digestive malignancies, gastric cancer (GC) pathobiology is still little known and understood. Recently, cytopathology and molecular biology on gastric juice/gastric lavage (GJ/GL) of GC patients have provided novel and interesting results in terms of screening, diagnosis, prognosis, and therapy. However, entertaining cytologic examination and molecular test as a unified solo-run test is previously unreported. Our aim was to assess the new parameter "GL Ca 72.4" for GC patients.

METHODS

Between April 2012 and July 2013, GJ/GL obtained from 37 surgical GC patients were tested for the presence/absence (GL1/GL0) of exfoliated malignant cells along with the intragastric concentration of Ca 72.4 (normal value <6.49 ng/mL: Ca 72.4n; elevated level ≥6.49 ng/mL: Ca 72.4+).

RESULTS

At a median follow-up of 79.3 months, all the GC alive patients were "GL0 Ca 72.4n." The "GL1 Ca 72.4+" parameter, in comparison with GL0 Ca 72.4n, strongly correlated with deeper tumor invasion (p = 0.027), severe nodal metastasis (p = 0.012), worst metastatic node ratio (p = 0.041), higher number of metastatic lymph nodes (30 vs. 20 nodes, p = 0.014), angiolymphatic invasion (p = 0.044), advanced stage (p = 0.034), and adjuvant therapy (p = 0.044). The Kaplan-Meier model showed that GL1 Ca 72.4+ subjects had shorter overall survival (OS) than GL0 Ca 72.4n cases (9.7 vs. 43.2 months, respectively, p = 0.042). At univariate analysis, the GL1 Ca 72.4+ parameter resulted a significant prognostic factor for OS (p = 0.023).

CONCLUSIONS

The combined cyto-molecular parameter "GL1 Ca 72.4+" appears to be a strong indicator of aggressive tumor behavior and a significant prognostic factor of poor survival for GC patients.

Free cancer cells in gastric cancer - methods of detection, clinical and prognostic importance (meta-analysis)

Gastric cancer (GC) is one of the most common malignant cancers worldwide. Intraperitoneal dissemination is the typical mechanism of the formation of metastases in GC. The diagnosis of the presence of intraperitoneal free cancer cells (IFCCs) is treated equally to the M (metastasis) category according to the 8^th edition of the TNM classification by the American Joint Committee on Cancer. IFCCs are cells which have detached from the primary tumour through exfoliation into the peritoneal cavity. The source of IFCCs may be iatrogenic due to improper surgical technique during resection of the tumour and may lead to intraperitoneal dissemination. Cytological examination of peritoneal lavage is considered as a gold standard in the confirmation of the presence of IFCCs; however, its sensitivity is very low. In order to increase the sensitivity and reliability of the examination, molecular biology techniques should be applied. In the case of detection of the presence of IFCCs in patients with GC, the patient should be qualified for chemotherapy, or possibly the use of hyperthermic intraperitoneal chemotherapy should be considered.

Short-Term Clinical Outcomes After Laparoscopic and Robotic Gastrectomy for Gastric Cancer: a Propensity Score Matching Analysis

BACKGROUND

The different advantages of laparoscopic gastrectomy (LG) and robotic gastrectomy (RG), two new minimally invasive surgical techniques for gastric cancer, remain controversial.

PURPOSE

To compare the short-term clinical outcomes of LG and RG.

METHODS

A retrospective, single-center comparative study of 1044 patients (LG = 750, RG = 294) was conducted. Patients undergoing LG and RG were matched (2:1 ratio) according to sex, age, BMI, extent of gastric resection, and pathologic stage. The primary outcomes were morbidity and mortality and perioperative recovery parameters; major types of complications were also analyzed.

RESULTS

After matching, 798 patients (LG = 532, RG = 266) were included. Both the LG and RG groups showed similar overall complication rates (LG = 12.8% vs RG = 12.4%) and operative mortality (LG = 0.4% vs RG = 0.4%). Compared to those who underwent LG, patients undergoing RG had significantly longer operative times (236.92 ± 57.28 vs 217.77 ± 65.00 min, p < 0.001), higher total costs (US$16,241.42 vs US$12,497, p < 0.001), less operative blood loss (77.07 ± 64.37 vs 103.68 ± 86.92 ml, p < 0.001), higher numbers of retrieved lymph nodes (32.0 vs 29.9, p < 0.001), and higher rates of retrieving more than 16 lymph nodes (94.0 vs 85.5%; p < 0.001). No significant differences between groups were noted in terms of the rate of reoperation, time until a soft diet was consumed, or length of hospital stay. The major complication and readmission rates were similar in both groups.

CONCLUSION

RG and LG produced similar short-term clinical outcomes, indicating that RG is a safe and beneficial surgical procedure.

Digestive tract reconstruction options after laparoscopic gastrectomy for gastric cancer

In addition to the popularity of laparoscopic gastrectomy (LG), many reconstructive procedures after LG have been reported. Surgical resection and lymphatic dissection determine long-term survival; however, the election of a reconstruction procedure determines the postoperative quality of life for patients with gastric cancer (GC). Presently, no consensus exists regarding the optimal reconstructive procedure. In this review, the current state of digestive tract reconstruction after LG is reviewed. According to the determining influence of the tumor site on the procedures of surgical resection and reconstruction, we divide these reconstruction procedures into three categories consistent with the resection procedures. We focus on the technical tips of every reconstruction procedure and examine the surgical outcomes (length of surgery and blood loss) and postoperative complications (anastomotic leakage and stricture) to facilitate gastrointestinal surgeons to understand the merits and demerits of every reconstruction procedure.

Deep neural network-assisted computed tomography diagnosis of metastatic lymph nodes from gastric cancer

BACKGROUND

Artificial intelligence-assisted image recognition technology is currently able to detect the target area of an image and fetch information to make classifications according to target features. This study aimed to use deep neural networks for computed tomography (CT) diagnosis of perigastric metastatic lymph nodes (PGMLNs) to simulate the recognition of lymph nodes by radiologists, and to acquire more accurate identification results.

METHODS

A total of 1371 images of suspected lymph node metastasis from enhanced abdominal CT scans were identified and labeled by radiologists and were used with 18,780 original images for faster region-based convolutional neural networks (FR-CNN) deep learning. The identification results of 6000 random CT images from 100 gastric cancer patients by the FR-CNN were compared with results obtained from radiologists in terms of their identification accuracy. Similarly, 1004 CT images with metastatic lymph nodes that had been post-operatively confirmed by pathological examination and 11,340 original images were used in the identification and learning processes described above. The same 6000 gastric cancer CT images were used for the verification, according to which the diagnosis results were analyzed.

RESULTS

In the initial group, precision-recall curves were generated based on the precision rates, the recall rates of nodule classes of the training set and the validation set; the mean average precision (mAP) value was 0.5019. To verify the results of the initial learning group, the receiver operating characteristic curves was generated, and the corresponding area under the curve (AUC) value was calculated as 0.8995. After the second phase of precise learning, all the indicators were improved, and the mAP and AUC values were 0.7801 and 0.9541, respectively.

CONCLUSION

Through deep learning, FR-CNN achieved high judgment effectiveness and recognition accuracy for CT diagnosis of PGMLNs.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, No. ChiCTR1800016787; http://www.chictr.org.cn/showproj.aspx?proj=28515.

Randomized clinical trial of extensive intraoperative peritoneal lavage versus standard treatment for resectable advanced gastric cancer (CCOG 1102 trial)

BACKGROUND

A survival benefit of extensive intraoperative peritoneal lavage (EIPL) has been reported in patients with gastric cancer with positive peritoneal cytology. The hypothesis of this study was that EIPL may reduce peritoneal recurrence in patients with advanced gastric cancer who undergo surgery with curative intent.

METHODS

This was an open-label, multi-institutional, randomized, phase 3 trial to assess the effects of EIPL versus standard treatment after curative gastrectomy for resectable gastric cancer of T3 status or above. The primary endpoint was disease-free survival (DFS); secondary endpoints were overall survival, peritoneal recurrence-free survival and incidence of adverse events.

RESULTS

Between July 2011 and January 2014, 314 patients were enrolled from 15 institutions and 295 patients were analysed (145 and 150 in the EIPL and no-EIPL groups respectively). The 3-year DFS rate was 63·9 (95 per cent c.i. 55·5 to 71·2) per cent in the EIPL group and 59·7 (51·3 to 67·1) per cent in the control group (hazard ratio (HR) 0·81, 95 per cent c.i. 0·57 to 1·16; P = 0·249). The 3-year overall survival rate was 75·0 (67·1 to 81·3) per cent in the EIPL group and 73·7 (65·9 to 80·1) per cent in the control group (HR 0·91, 0·60 to 1·37; P = 0·634). Peritoneal recurrence-free survival was not significantly different between the two groups (HR 0·92, 0·62 to 1·36; P = 0·676). No intraoperative complications related to EIPL were observed.

CONCLUSION

EIPL did not improve survival or peritoneal recurrence in patients who underwent gastrectomy for advanced gastric cancer. Registration number: 000005907 (http://www.umin.ac.jp/ctr/index.htm).

Laparoscopic endoscopic cooperative surgery (LECS) for the gastrointestinal tract: Updated indications

Laparoscopic and endoscopic cooperative surgery (LECS) is a procedure combining laparoscopic gastric resection with endoscopic submucosal dissection for local resection of gastric tumors with appropriate, minimal surgical resection margins. The LECS concept was initially developed from the classical LECS procedure for gastric submucosal tumor resection. Many researchers reported that classical LECS was a safe and feasible technique for resection of gastric submucosal tumors, regardless of tumor location, including the esophagogastric junction. Recently, LECS was approved for insurance coverage by Japan's National Health Insurance plan and widely applied for gastric submucosal tumor resection. However, the limitations of classical LECS are the risk of abdominal infection, scattering of tumor cells in the abdominal cavity, and tumor cell seeding in the peritoneum. The development of modified LECS procedures, such as inverted-LECS, non-exposed endoscopic wall-inversion surgery, a combination of laparoscopic and endoscopic approaches to neoplasia with a non-exposure technique, and closed-LECS, has almost resolved these drawbacks. This has led to a recent increase in the indication of modified LECS to include patients with gastric epithelial neoplasms. The LECS concept is also beginning to be applied to tumor excision in other organs, such as the duodenum, colon and rectum. Further evolution of LECS procedures is expected in the future. Sentinel lymph node mapping could also be combined with LECS, resulting in a portion of early gastric cancers being treated by LECS with sentinel node mapping.

Robotic total gastrectomy with π-shaped esophagojejunostomy using a linear stapler as a novel technique

OBJECTIVE

To evaluate the intraoperative and short-term postoperative outcomes of a novel robotic intracorporeal π-shaped esophagojejunostomy (EJS) after D2 total gastrectomy (TG) using the Da Vinci robotic surgical system for intracorporeal anastomosis after TG.

BACKGROUND

Intracorporeal π-shaped EJS, using a linear stapler, was recently reported for laparoscopic total gastrectomy in patients with gastric cancer. However, robotic intracorporeal π-shaped EJS using a linear stapler has not been reported. This report aimed to describe the use of a novel technique for π-shaped EJS using the Da Vinci robotic system.

METHODS

Robotic intracorporeal π-shaped esophagojejunostomy after total gastrectomy was performed in 11 consecutive patients diagnosed with early gastric cancer, and their perioperative outcomes were analyzed.

RESULTS

All the operations were successful without conversion to open or laparoscopic surgery and postoperative complications. The total number of patients was 11 (7 males and 4 females). The mean age of the patients was 63.36 ± 10.56 years old. Seven patients were diagnosed with cardia cancer, 3 patients were diagnosed with gastric body cancer, and 1 patient was diagnosed with gastric antrum cancer. The patients' mean proximal resection margin was 3.18 ± 1.17 cm, the distal resection margin was 6.18 ± 1.40 cm, the mean length of the incision was 4.55 ± 0.69 cm, the mean operative time was 287.27 ± 30.69 min, the mean day of first flatus was 3.27 ± 0.79 days, the mean day of the start of diet was 2.91 ± 0.94 days, the mean postoperative hospital stay was 11.45 ± 5.13 days, and the mean operative blood loss was 47.27 ± 31.33 ml. No complications were observed during anastomosis, and the median anastomosis time was 19.5 min. The mean number of lymph node dissections was 17.91 ± 4.59, the mean number of positive lymph nodes was 0.45 ± 0.69, all patients were diagnosed with stage I-II gastric cancer, and the mean maximum diameter of the tumor was 2.67 ± 1.30 cm. All the patients had a smooth hospital discharge.

CONCLUSION

A novel robotic gastrectomy with intracorporeal π-shaped EJS for esophagojejunal anastomosis described and shows acceptable resulted. This technique has the potential to offer better short-term surgical outcomes and overcomes the drawbacks of laparoscopy with a decreased risk of complications during and after surgery.

Gastric washing by distilled water can reduce free gastric cancer cells exfoliated into the stomach lumen

PURPOSE

Intragastric free cancer cells in patients with gastric cancer have rarely been studied. The purpose of this study was to investigate the detection rate of intragastric free cancer cells in gastric washes using two types of solutions during endoscopic examination. We further clarified risk factors affecting the presence of exfoliated free cancer cells.

METHODS

A total of 175 patients with gastric cancer were enrolled. Lactated Ringer's solution (N = 89) or distilled water (DW; N = 86) via endoscopic working channel was sprayed onto the tumor surface, and the resultant fluid was collected for cytological examination. We compared the cancer-cell positivity rate between the two (Ringer and DW) groups. We also tested the correlation between cancer-cell positivity and clinicopathological factors in the Ringer group to identify risk factors for the presence of exfoliated cancer cells.

RESULTS

The cancer-cell positivity rate was significantly higher in the Ringer group than that in the DW group (58 vs 6%). Cytomorphology in the Ringer group was well maintained, but not in the DW group. The larger tumor size (≥ 20 mm) and positive lymphatic involvement were significant risk factors of exfoliated free cancer cells.

CONCLUSIONS

Cancer cells can be highly exfoliated from the tumor surface into the gastric lumen by endoscopic irrigation in large gastric cancer with lymphatic involvement. Gastric washing by DW can lead to cytoclasis of free cancer cells; therefore, it may minimize the possibility of cancer-cell seeding in procedures carrying potential risks of tumor-cell seeding upon transluminal communication, such as endoscopic full-thickness resection and laparoscopy-endoscopy cooperative surgery.

Interaction between Medical Treatment and Minimally Invasive Surgical Treatment for the Malignancies of the Digestive Tract

Recently, endoscopic diagnosis and treatment methods for early cancer in the digestive tract have made rapid progress. As for surgery, laparoscopic and thoracoscopic techniques have achieved rapidly advancing development in the last 2 decades. Early detection of the malignant lesion and the evolution of endoscopic and surgical device enabled in performing the minimally invasive surgery. Collaboration of medical treatment and minimally invasive surgery for advanced cancer is ongoing in the case of some conditions and in a few institutes. In this review, the contents of the core symposia on "Interaction between medical treatment and minimally invasive surgical treatment for the malignancies of the digestive tract", held at the 11, 12 and 13th annual meeting of the Japanese Gastroenterological Association, are summarized. At each annual meeting, the core symposium focused primarily on gastric, colorectal, and esophageal cancer treatment. For gastric cancer, endoscopic resection and laparoscopic surgery were 2 important key words. For colorectal cancer, multidisciplinary therapy was a major key word. And for esophageal cancer, endoscopic resection, chemoradiotherapy, thoracoscopic surgery and salvage surgery were key words. Patients' survival and quality of life are expected to further advance as a result of the collaboration of such therapeutic modalities.

Robotic Versus Laparoscopic Gastrectomy for Locally Advanced Gastric Cancer

Robotic gastrectomy (RG) has progressed rapidly in the last decade, overcoming many obstacles in laparoscopic technology. We compared surgical performance and short-term clinical outcomes between RG and laparoscopic gastrectomy (LG). In total, 163 patients with gastric cancer were randomly treated with RG (n=102) or LG (n=61). D2 lymphadenectomy was achieved in all patients. Digestive tract reconstruction in the RG group was performed by intracorporeal hand sewing, but extracorporeal anastomosis in the LG group was performed with a 25-mm circular stapler or linear stapler. Compared with the LG group, the RG group had less intraoperative blood loss (P=0.005) and more lymph nodes retrieved (P=0.000). Postoperative complications between the 2 groups were not significantly different during the 11-month follow-up (P=0.063). Compared with LG, RG is a feasible and safe approach with minimally invasive, satisfactory intracorporeal digestive tract reconstruction, and fast recovery. Multicenter randomized controlled studies of larger numbers of patients are needed.

Detection of carcinoembryonic antigen in peritoneal fluid of patients undergoing laparoscopic distal gastrectomy with complete mesogastric excision

Background

Surgery for gastric cancer may result in free intraperitoneal cancer cells. This study aimed to determine whether laparoscopic gastrectomy with complete mesogastric excision (D2 + CME) reduces the number of free intraperitoneal cancer cells.

Methods

Patients with gastric cancer who had a conventional D2 or D2 + CME laparoscopic distal gastrectomy between April 2015 and February 2017 were included in the study. Intraoperative peritoneal washings were collected before and after tumour resection. Reverse transcriptase–quantitative real-time PCR for carcinoembryonic antigen (CEA) was used to assess the presence of gastric cancer cells.

Results

Eighty-five patients underwent conventional D2 lymphadenectomy and 76 had the D2 + CME procedure. Of 161 peritoneal fluid samples obtained before gastrectomy, 137 (D2, 72; D2 + CME, 65) had low CEA expression indicative of no cancer cells. After gastrectomy, high CEA expression was detected in 23 of the 72 samples (32 per cent) from patients in the D2 group, and in ten of the 65 samples (15 per cent) from the D2 + CME group. In the overall cohort, mean CEA expression level after gastrectomy was lower in the D2 + CME group than in the D2 group (P = 0·0038). In patients with low CEA expression before gastrectomy, disease-free survival in the D2 + CME group was better than that in the D2 group (P = 0·033).

Conclusion

Laparoscopic distal gastrectomy with complete mesogastric excision reduces the number of free intraperitoneal cancer cells and is associated with a better disease-free survival than conventional D2 gastrectomy.

Characteristics and survival outcomes related to the infra-pyloric lymph node status of gastric cancer patients

BACKGROUND

To study metastasis to the infra-pyloric (no. 6) lymph nodes and their subgroups and the related risk factors of gastric cancer patients.

METHODS

Gastric cancer patients who underwent gastrectomy with complete postoperative pathological information on the no. 6 lymph node station and its subgroups from January 1, 2008, to December 31, 2011, were included. The clinicopathological characteristics and survival outcomes were analyzed.

RESULTS

A total of 121 patients were included; they had 6.1 ± 7.7 positive lymph nodes, and 35.1 ± 14.2 lymph nodes were examined. The overall lymph node positivity rate was 67.8% (82/121) with a positivity rate of 28.1% (34/121) for the no. 6 lymph nodes. The metastasis rate was 6.6% for the no. 6a nodes, 6.6% for the no. 6b nodes, and 21.5% for the no. 6c nodes. Also, no. 8a (OR = 1.329, p = 0.017) and no. 9 (OR = 1.250, p = 0.022) nodal positivity and lower third tumor location (OR = 1.278, p = 0.001) were independent risk factors for no. 6 lymph nodal metastasis. There was a significant survival difference between patients with positive and negative no. 6 lymph nodes and patients with metastasis to other lymph node stations (p <  0.001).

CONCLUSIONS

Patients with no. 6 lymph node metastasis have poor survival outcomes. Complete infra-pyloric lymphadenectomy is necessary and crucial for gastric cancer patients.

Robotic oesophago-gastric cancer surgery

A postoperative complications rate of nearly 50% has compelled oesophago-gastric practice to adopt minimally invasive techniques such as robotic surgery

Tumor manipulation during pancreatic resection for pancreatic cancer induces dissemination of tumor cells into the peritoneal cavity: a systematic review

BACKGROUND

Intraoperative tumor manipulation may induce the dissemination of occult peritoneal tumor cells (OPTC) into the peritoneal cavity.

METHODS

A systematic review was performed in the PubMed, Embase and Cochrane databases from inception to March 15, 2017. Eligible were studies that analyzed the presence of OPTC in peritoneal fluid, by any method, both before and after resection in adults who underwent intentionally curative pancreatic resection for histopathologically confirmed pancreatic ductal adenocarcinoma in absence of macroscopic peritoneal metastases.

RESULTS

Four studies with 138 patients met the inclusion criteria. The pooled rate of OPTC prior to tumor manipulation was 8% (95% CI 2%-24%). The pooled detection rate of OPTC in patients in whom OPTC became detectable only after tumor manipulation was 33% (95% CI 15-58%). Only one study (28 patients) reported on survival, which was worse in patients with OPTC (median 11.1 months versus 30.3 months; p = 0.030).

CONCLUSION

This systematic review suggests that tumor manipulation induces OPTC in one third of patients with pancreatic cancer. Since data on survival are lacking, future studies should determine the prognostic consequences of tumor manipulation, including the potential therapeutic effect of 'no-touch' and minimally invasive resection strategies.

Preoperative gastric lavage in gastric cancer patients undergoing surgical, endoscopic or minimally invasive treatment: An oncological measure preventing peritoneal spillage of intragastric cancer cells and development of related metastases

In addition to classical metastatic pathways, recently gastric cancer was described having an alternative route called "endoluminal exfoliation". Provisional analyses demonstrated, in fact, this kind of shedding is associated with several clinico-pathological features indicative of aggressive behavior and resulted to be an independent prognostic factor entailing poor prognosis. Compared with non-sowing counterparts, in fact, patients affected with exfoliating early and advanced gastric carcinomas met with shorter overall survival, disease free survival, progression free survival and time to tumor progression. In spite of these interesting results, however, the clinico-pathological and oncological significance of this unconventional metastatic route is still to be clarified. Such an investigation is further urged by the increasing widespread employment of minimally invasive treatments for gastric cancer which include a wide spectrum of intragastric interventions and maneuvers. Indeed, endoscopic mucosal resection, endoscopic submucosal dissection, endoscopic full-thickness resection, intragastric laparoscopic surgery and hybrid procedures all take place inside of the stomach. However, iatrogenic perforations can occur during execution of these treatments leading to spillage of malignant cells from gastric to the peritoneal cavity or trocar insertion sites. Furthermore, many other gastric conditions and interventions can collide with endogastric presence of floating cancer cells: spontaneous ulceration or perforation, laparotomy surgery, gastrointestinal occlusion, diverticula. Viability, migration and intraluminal transportability of the intragastric floating cancer cells represents another original and intriguing topic. All these considerations led us to entertain the hypothesis that removing the exfoliated cancer cells from the gastric lumen could save patients from the dreaded potential risk of spillage. Performing gastric lavage before starting any kind of tumor intervention could be the most appropriate procedure to adopt with prophylactic intent. Should our speculation prove to be clinically significant, preoperative gastric lavage should be pointed out as a simple but cogent method useful for preventing oncological mishaps such as spillage of gastric cancer cells and development of related recurrences or metastases.

Potential for peritoneal cancer cell seeding in endoscopic full-thickness resection for early gastric cancer

BACKGROUND AND AIMS

During endoscopic full-thickness resection (EFTR) for cancers, whether exposure of the lumen to the abdominal cavity during the procedure is acceptable is controversial because of the potential risk of tumor cell seeding. To assess the possibility of transplantation as a result of contact with tumor cells during the procedure, we prospectively investigated the ability of cancer cells to be detached by touching the tumor surface.

METHODS

In 48 patients with a single early gastric cancer resected by endoscopic submucosal dissection, stamp cytology was performed by touching the surface of the specimens to glass slides. Samples were obtained from cancerous and noncancerous areas, constituting the study and control groups, respectively. The detection rate of malignant class IV or V (C-IV/C-V) samples was investigated with Papanicolaou staining. The rate of CD44v9-positive cases, a cancer stem cell marker, was assessed in C-IV/C-V samples with immunohistochemical staining.

RESULTS

Detection rates of C-IV/C-V samples in the cancerous group (53/192 slides, 27.6%) differed significantly from those of the C-IV/C-V samples in the noncancerous group (0/96 slides, 0%). Among the 53 slides of C-IV/C-V samples in the cancerous group, CD44v9 cells were expressed in 18 slides (34.0%).

CONCLUSIONS

These data suggest that cancer cells, including cancer stem cells, in early gastric cancers are easily detached via contact with the tumor surface. In EFTR, a nonexposure approach is recommended to avoid the risk of iatrogenic cancer cell seeding via contact with and transplantation of cancer cells.

Impact of an Ultrasonically Activated Device in Robot-Assisted Distal Gastrectomy

Objective

Robot-assisted gastrectomy is increasingly used for the treatment of gastric cancer, although it remains a time-consuming procedure. An ultrasonically activated device might be useful to shorten operation times. This study therefore assessed the effect of ultrasonically activated device use on procedural times and on other early surgical outcomes.

Methods

Consecutive patients (N = 42) who underwent robot-assisted distal gastrectomy for gastric cancer were included. Clinicopathological characteristics and early surgical outcomes were compared between robotic-assisted gastrectomy procedures using an ultrasonically activated device (U group, n = 21) and those without it (NU group, n = 21).

Results

There were no significant differences in patient characteristics between the groups; however, the median operation time was significantly less in the U group than in the NU group (291 vs 351 minutes, P = 0.006). In detail, the median duration of console time until dividing the duodenum was less in the U group (70 vs 102 minutes, P < 0.001). Estimated blood loss, incidence of postoperative morbidity, and duration of postoperative hospital stay were not different between the groups.

Conclusions

An ultrasonically activated device reduced the operation time of robot-assisted gastrectomy without increasing blood loss and morbidity.