Intraoperative dissemination during gastrectomy for gastric cancer associated with serosal invasion

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.

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.

Prediction of serosal invasion in gastric cancer: development and validation of multivariate models integrating preoperative clinicopathological features and radiographic findings based on late arterial phase CT images

BACKGROUND

To develop and validate multivariate models integrating endoscopic biopsy, tumor markers, and CT findings based on late arterial phase (LAP) to predict serosal invasion in gastric cancer (GC).

METHODS

The preoperative differentiation degree, tumor markers, CT morphological characteristics, and CT value-related and texture parameters of 154 patients with GC were analyzed retrospectively. Multivariate models based on regression analysis and machine learning algorithms were performed to improve the diagnostic efficacy.

RESULTS

The differentiation degree, carbohydrate antigen (CA) 199, CA724, CA242, and multiple CT findings based on LAP differed significantly between T1-3 and T4 GCs in the primary cohort (all P < 0.05). Multivariate models based on regression analysis and random forest achieved AUCs of 0.849 and 0.865 in the primary cohort, respectively.

CONCLUSION

We developed and validated multivariate models integrating endoscopic biopsy, tumor markers, CT morphological characteristics, and CT value-related and texture parameters to predict serosal invasion in GCs and achieved favorable performance.

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.

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.

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.

Use of peritoneal washing cytology for the detection of free peritoneal cancer cells before and after surgical treatment of gastric adenocarcinoma

AIM

Cytological detection of peritoneal-free gastric cancer cells is considered as the gold standard with variable sensitivity. Seeding of cancer cells after radical surgery for gastric cancer is a controversial issue. In this study, it was aimed to detect the rate of positive peritoneal washing cytology and the incidence of spreading of tumor cells after radical surgery.

MATERIALS AND METHODS

Patients with pathologically proven and surgically treated gastric adenocarcinoma were enrolled. Three peritoneal washing samples were examined cytologically: at the beginning, after completion of resection, and before closure of the abdomen. Identification of peritoneal-free gastric cancer cells was regarded as the main outcome.

RESULTS

Thirty-four patients with a mean age of 60.7 ± 12 years were enrolled. T3 and N0 were the most common stages seen in 16 (47%) and 12 patients (35.3%), respectively. There were two positive results (5.9%) as the first peritoneal sample. Considering T3- or N-positive patients, the incidence increased to 9.1%. There was no conversion of negative to positive cytology. Cytological positivity remained only in one case (2.9%) after the second and the third peritoneal samples.

CONCLUSION

Rate of positive peritoneal washing cytology in patients with gastric cancer is influenced by clinicopathological findings and the technique used. Use of cytology alone is thought to be failed to detect free cancers cells within the peritoneal cavity.

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.

Extensive peritoneal lavage after curative gastrectomy for gastric cancer (EXPEL): study protocol of an international multicentre randomised controlled trial

Peritoneal recurrence after gastrectomy for gastric cancer is common and the prognosis is dismal. Recent evidence suggests that extensive peritoneal lavage with large volume of normal saline after surgery before abdominal closure can reduce the risk of peritoneal recurrence and improve overall survival. This study aims to evaluate the benefit of extensive intraoperative peritoneal lavage. This is a prospective, open-label, multicentre randomised controlled trial involving 15 international centres in China, Korea, Japan, Malaysia and Singapore. Patients with cT3/4 stomach cancer undergoing curative resection are randomised to either extensive peritoneal lavage (10 l of saline) or standard lavage (≤2 l of saline). The primary outcome is overall survival and secondary outcomes include disease-free survival and peritoneal recurrence. The minimum sample size is 600 subjects with 300 per arm completing 3 years follow-up. The data will be analysed on an intention-to-treat basis, assuming a two-sided test with a 5% level of significance.

Blockade of potassium ion transports enhances hypotonicity-induced cytocidal effects in gastric cancer

Background

Peritoneal lavage with distilled water has been used for surgeries of various cancers to reduce peritoneal recurrence. This study examined whether blockade of potassium ion transports enhances hypotonicity-induced cytocidal effects in gastric cancer (GC).

Results

A potassium channel blocker inhibited the occurrence of regulatory volume decrease (RVD) induced by mild hypotonic stimulation, and significantly enhanced cytocidal effects on GC cells. Incubating MKN45 cells with hypotonic solutions containing a potassium channel blocker significantly reduced the formation of peritoneal metastases in nude mice.

Methods

The three human GC cell lines (HGC-27, Kato III, and MKN45) were exposed to mild hypotonic solutions, and the effects of blockade of potassium ion transports during hypotonic stimulation on cell volume changes and cell viabilities were examined. In the in vivo study, MKN45 cells stimulated with mild hypotonic solutions were intraperitoneally injected into nude mice, and the effects of blockade of potassium ion transports during hypotonic stimulation on the formation of peritoneal metastases were evaluated.

Conclusions

Blockade of potassium ion transports enhances hypotonicity-induced cytocidal effects on GC cells, which may contribute to development of a novel lavage method for further reduction of peritoneal recurrence in GC.

Assessment of Hyperthermic Intraperitoneal Chemotherapy to Eradicate Intraperitoneal Free Cancer Cells

OBJECTIVE: To assess the effect of hyperthermic intraperitoneal chemotherapy (HIPEC) to eradicate intraperitoneal free cancer cells and to explore the feasibility of cytological cure for peritoneal carcinomatosis (PC). METHODS: The peritoneal lavage fluid (or ascites) from 50 PC patients was collected before and after intraoperative HIPEC, respectively, for conventional cytology test, and conventional and real-time quantitative reverse transcript polymerase chain reaction detecting carcinoembryonic antigen (CEA) mRNA and cytokeratin-20 (CK20) mRNA. The blood samples 3 days before and 7 days after intraoperative HIPEC were also collected for detecting the serum tumor markers, including CEA, carbohydrate antigen (CA) 125, and CA19-9. RESULTS: The positive rate of conventional cytology test before HIPEC versus after HIPEC was100.0% versus 22.0% (P = .000). The positive rates of CEA mRNA and CK20 mRNA before HIPEC versus after HIPEC were 100.0% versus 86.0% (P = .012) and 100.0% versus 96.0% (P = .495), respectively. Moreover, after HIPEC, 18 (36.0%) patients had a decline in CEA mRNA (P = .000), and 17 (34.0%) patients had a decline in CK20 mRNA (P = .000). The positive rates of serum CEA, CA125, and CA199 before HIPEC versus after HIPEC were 52.0% versus 28.0% (P = .014), 52.0% versus 44.0% (P = .423), and 40.0% versus 28.0% (P = .205), respectively. CONCLUSION: HIPEC could effectively eradicate intraperitoneal free cancer cells and partially achieve cytological cure for PC.