Percutaneous Peritoneal Lavage for the Rapid Staging of Gastric and Pancreatic Cancer

Safety and feasibility of percutaneous abdominal lavage cytology screening (PACS) prior to surgical resection for pancreatic cancer

PURPOSE

This study aimed to evaluate the feasibility, safety, diagnostic yield, and technical aspects of percutaneous abdominal lavage cytology screening (PACS) in patients with resectable pancreatic cancer.

METHODS

This single-center, retrospective study included patients with resectable pancreatic cancer who underwent PACS before pancreatectomy between May 2022 and October 2023. The technical success rate, position of the drainage tube, volume of fluid administered, volume of fluid retrieved, fluid retrieval rate, and adverse events were evaluated. The cytological results of PACS were compared with those of surgical peritoneal lavage performed during pancreatectomy.

RESULTS

Forty-four patients were enrolled in this study. The technical success rate for PACS was 100%. Drainage tube placement was outside the pouch of Douglas in all patients in the right-sided abdominal approach group (n = 10), whereas the placement was in the pouch of Douglas in all patients in the suprapubic approach group (n = 34). The mean volume of fluid administered, mean volume of fluid retrieved, and fluid retrieval rate were 185.0 ± 22.9 ml vs. 97.1 ± 32.0 ml (p < 0.001), 36.8 ± 25.6 ml vs. 50.5 ± 21.6 ml (p = 0.059), and 19.0 ± 12.4% vs. 54.9 ± 21.9% (p < 0.001) in the right abdominal approach and suprapubic approach groups, respectively. No adverse events were reported. The cytological results were benign in 42 patients; no discrepancy was observed in the results of surgical peritoneal lavage (n = 36).

CONCLUSION

PACS is a feasible and safe procedure that can be performed before pancreatectomy in patients with resectable pancreatic cancer. the suprapubic approach may be ideal and PACS could be a screening method to detect carcinomatous peritonitis.

Exosomal ROR1 in peritoneal fluid identifies peritoneal disseminated PDAC and is associated with poor survival

Background

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest forms of cancer and peritoneal dissemination is one major cause for this poor prognosis. Exosomes have emerged as promising biomarkers for gastrointestinal cancers and can be found in all kinds of bodily fluids, also in peritoneal fluid (PF). This is a unique sample due to its closeness to gastrointestinal malignancies. The receptor tyrosine kinase-like orphan receptor 1 (ROR1) has been identified as a potential biomarker in human cancers and represents a promising target for an immunotherapy approach, which could be considered for future treatment strategies. Here we prospectively analyzed the exosomal surface protein ROR1 (exo-ROR1) in PF in localized PDAC patients (PER-) on the one hand and peritoneal disseminated tumor stages (PER+) on the other hand followed by the correlation of exo-ROR1 with clinical-pathological parameters.

Methods

Exosomes were isolated from PF and plasma samples of non-cancerous (NC) (n = 15), chronic pancreatitis (CP) (n = 4), localized PDAC (PER-) (n = 18) and peritoneal disseminated PDAC (PER+) (n = 9) patients and the surface protein ROR1 was detected via FACS analysis. Additionally, soluble ROR1 in PF was analyzed. ROR1 expression in tissue was investigated using western blots (WB), qPCR, and immunohistochemistry (IHC). Exosome isolation was proven by Nano Tracking Analysis (NTA), WB, Transmission electron microscopy (TEM), and BCA protein assay. The results were correlated with clinical data and survival analysis was performed.

Results

PDAC (PER+) patients have the highest exo-ROR1 values in PF and can be discriminated from NC (p <0.0001), PDAC (PER-) (p <0.0001), and CP (p = 0.0112). PDAC (PER-) can be discriminated from NC (p = 0.0003). In plasma, exo-ROR1 is not able to distinguish between the groups. While there is no expression of ROR1 in the exocrine pancreatic tissue, PDAC and peritoneal metastasis show expression of ROR1. High exo-ROR1 expression in PF is associated with lower overall survival (p = 0.0482).

Conclusion

With exo-ROR1 in PF we found a promising diagnostic and prognostic biomarker possibly discriminating between NC, PDAC (PER-) and PDAC (PER+) and might shed light on future diagnostic and therapeutic concepts in PDAC.

Techniques of staging laparoscopy and peritoneal fluid assessment in gastric cancer: a systematic review

BACKGROUND

Staging laparoscopy for gastric cancer is recommended to assess the tumor's locoregional extension and exclude peritoneal disease. As there is no consensus on optimizing the procedure's diagnostic accuracy, we aimed to systematically review the literature on operative techniques, followed by peritoneal lavage fluid assessment in gastric cancer patients. Specifically, we sought to indicate the most common characteristics of the procedure and cytological evaluation.

METHODS

This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The protocol for this systematic review was registered on PROSPERO database (CRD: 42022306746). On September 2022, a search was carried out using Embase, Medline ALL, Cochrane Central Register of Controlled Trials, and Web of Science Core Collection.

RESULTS

The search identified 1632 studies on staging laparoscopy and 2190 studies on peritoneal fluid assessment. Some 212 studies were included. Open Hasson was the method of choice in accessing the peritoneal cavity in 65% of the studies, followed by establishing a pneumoperitoneum at 10-12 mmHg in 52% of reports. Most frequently, the patient was positioned supine (70%), while a 30° scope and three ports were used to assess the peritoneal cavity clockwise (72%, 77%, and 85%, respectively). Right and left upper abdomen quadrants were the predominant area of laparoscopic exploration (both 65%), followed by the primary tumor region (54%), liver and pelvis (both 30%), and small bowel and spleen (19% and 17%, respectively). Regions of peritoneal lavage and aspiration were limited to the pelvis (50%), followed by right and left upper abdomen quadrants (37.5% and 50%, respectively). No studies compared different methods of operative techniques or analysis of ascites/fluid.

CONCLUSIONS

This study indicates a high heterogeneity in the technique of staging laparoscopy and peritoneal fluid assessment in gastric cancer patients. Further research and initiatives to reach a consensus on the standardization of the procedure are warranted.

Staging CT and Diagnostic Laparoscopy With Cytology Prior to the Treatment of Pancreatic Adenocarcinoma: A Case Series

INTRODUCTION

Initial staging of pancreatic ductal adenocarcinoma (PDAC) is performed with computed tomography (CT). Laparoscopy with peritoneal cytology at staging can uncover occult disease undetected by CT. This case series assessed clinical course following staging laparoscopy with cytology in patients with PDAC.

METHODS

This single-center study examined patients with non-metastatic PDAC diagnosed from 2017 to 2020. Patients underwent CT and subsequent laparoscopy with cytology prior to treatment. Demographics, clinicopathologic status, treatment course, and survival were compared.

RESULTS

Eight patients were identified. All had negative laparoscopies. Five cytologies were negative, two were atypical, and one was positive. Two patients with negative cytology received neoadjuvant chemotherapy and underwent resection, with an average follow-up time of 32.9 months since diagnosis. Of the three remaining patients with negative cytology, none underwent resection. One received delayed chemotherapy, while the others could not due to medical contraindications. The average survival was 3.5 months (n=2). Of two patients with atypical cytology, neither underwent resection. One could not receive chemotherapy due to medical contraindication, while the other was lost to follow-up shortly after diagnosis. The average survival was 1.3 months (n=1). The patient with positive cytology received definitive chemotherapy without resection and survived for 21.6 months.

CONCLUSIONS

The patient with positive cytology may have been spared non-therapeutic surgery. Remaining unresected patients showed poor survival, though the lack of immediate chemotherapy may contribute to this finding. Further research is needed to determine optimal candidates for invasive staging and implications of atypical cytology.

Should Positive Cytology Revealed by Intraoperative Lavage Preclude Radical Resection in Resectable Pancreatic Cancer?: A Systemic Review and Meta-analysis

OBJECTIVES

The aims of this review were to determine whether positive peritoneal lavage cytology (CY+) precludes radical resection in pancreatic cancer and to propose prospections for future studies.

METHODS

MEDLINE, Embase, and Cochrane Central were searched for related articles. Dichotomous variables and survival outcomes were analyzed with the estimation of odds ratio and hazards ratio (HR), respectively.

RESULTS

A total of 4905 patients were included, of which 7.8% were CY+. Positive peritoneal lavage cytology was correlated with poor overall survival (univariate survival analysis [HR, 2.35; P < 0.00001]; multivariate analysis [HR, 1.62; P < 0.00001]), poor recurrence-free survival (univariate survival analysis [HR, 2.50; P < 0.00001]; multivariate analysis [HR, 1.84; P < 0.00001]), and higher initial peritoneal recurrence rate (odds ratio, 5.49; P < 0.00001).

CONCLUSIONS

Although CY+ predicts poor prognosis and a higher risk of peritoneal metastasis after curative resection, it is not sufficient to preclude curative resection based on the current evidence, and high-quality trials should be conducted to assess the prognostic impact of operation among resectable CY+ patients. In addition, more sensitive and accurate methods to detect peritoneal exfoliated tumor cells and more effective comprehensive treatment for resectable CY+ pancreatic cancer patients are clearly warranted.

The value of potassium, pH and D-dimer levels in early diagnosis of acute mesenteric ischemia: an experimental study on rats

INTRODUCTION

The aim of this randomized controlled experimental study was to evaluate the efficacy of potassium, pH and D-dimer levels in blood, as well as potassium and pH levels in peritoneal lavage fluid, in the early diagnosis of acute mesenteric ischemia.

MATERIAL AND METHODS

This study was conducted at the Istanbul University Center of Experimental Medicine after having received approval from the Istanbul University animal testing ethics committee. Male albino Wistar rats (n = 24; 250 to 350 g) were divided into two control groups and two ischemic groups. Levels of potassium, pH, and D-dimer in blood and levels of potassium and pH in peritoneal lavage fluid were analyzed for 1 h and 2 h after the induced acute mesenteric ischemia procedure. The degree of ischemic injury was determined using the histopathological damage score in tissue samples taken from the terminal ileum.

RESULTS

Ischemic groups had statistically significant differences in potassium and pH in blood and peritoneal lavage fluid compared to non-ischemic groups (p < 0.05). There was no significant difference between control and ischemic groups in terms of D-dimer and histologic grading results after 1 h (p = 0.132, p = 0.475 respectively), while there was a significant difference between control and ischemic groups after 2 h (p < 0.05).

CONCLUSIONS

The levels of potassium, pH, and D-dimer could be useful in daily practice for the early diagnosis of acute mesenteric ischemia.

A decision analysis comparing three strategies for peritoneal lavage cytology testing in staging of gastric cancer in China

BACKGROUND

Positive peritoneal cytology (PCY) indicates metastasis (M1) in gastric cancer (GC) patients; both the American and Chinese guidelines recommend laparoscopic peritoneal lavage (LPL) for cytology. However, relatively high costs impair the widespread use of LPL in some resource-limited regions in China, and the cost-effectiveness of PCY testing remains unclear. Therefore, we performed a decision analysis to evaluate the cost-effectiveness of PCY testing by comparing the guideline-recommended intraoperative LPL, a newly proposed preoperative percutaneous peritoneal lavage (PPL), and a third strategy of exploratory laparotomy with no cytology testing (ELNC) among GC patients.

METHODS

We developed a decision-analytic Markov model of the aforementioned three strategies for a hypothetical cohort of GC patients with curative intent after initial imaging, from the perspective of Chinese society. We estimated costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) as primary outcomes; we also conducted one-way and probabilistic sensitivity analyses to investigate the model's robustness.

RESULTS

We found that ELNC was dominated (i.e., more expensive and less effective) by PPL and LPL. LPL was the most cost-effective method with an ICER of US$17,200/QALY compared to PPL, which was below the Chinese willingness-to-pay (WTP) threshold of US$29,313 per QALY gained. In sensitivity analyses, PPL was more likely to be cost-effective with a lower WTP threshold.

CONCLUSIONS

Cytology testing through either LPL or PPL was less expensive and more effective than ELNC among GC patients. Moreover, LPL was the most cost-effective modality at the current WTP threshold, while PPL could potentially be cost-effective in lower-income areas.

Hyperthermic intraperitoneal chemotherapy combined with systemic chemotherapy for gastric cancer peritoneal carcinomatosis: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The prognosis of gastric cancer peritoneal carcinomatosis (GCPC) remains poor despite recent advances in systemic chemotherapy (SC) with an average survival less than 6 months. Current evidence supporting the utility of hyperthermic intraperitoneal chemotherapy (HIPEC) combined with SC for GCPC is limited. We plan to provide a systematic review and meta-analysis of randomized controlled trials to evaluate the comparative effects and safety of HIPEC combined with SC in the management of GCPC.

METHODS

Randomized controlled trials evaluating HIPEC combined with SC versus SC as first-line treatment for GCPC will be searched in MEDLINE, EMBASE, Web of Science, the Cochrane Library, ClinicalTrials.gov, and Google Scholar, from database inception to April 30, 2020. Data on study design, participant characteristics, intervention details, and outcomes will be extracted. Primary outcomes to be assessed are: median progression-free survival; secondary outcomes are: median survival time, 1- year survival rate, 2-year survival rate, objective response rate, and adverse events. Meta-analysis will be performed using RevMan V.5.3 statistical software. Data will be combined with a random effect model. Study quality will be assessed using the Cochrane Risk of Bias Tool. Heterogeneity will be assessed, and if necessary, a subgroup analysis will be performed to explore the source of heterogeneity.

RESULTS

The results will provide useful information about the effectiveness and safety of HIPEC combined with systemic chemotherapy regimens in patients with gastric cancer peritoneal carcinomatosis.

CONCLUSION

The findings of the study will be disseminated through peer-reviewed journal.

THE REGISTRATION NUMBER

INPLASY202050006.

DOI NUMBER

10.37766/inplasy2020.5.0006.

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.

The use of intraperitoneal chemotherapy for gastric malignancies

Introduction: Gastric cancer is the fourth/fifth most common malignancy worldwide, with only a quarter of patients achieving a 5-year survival rate. It has been estimated that 15-50% or more of patients have peritoneal disease upon surgical exploration. Until the early 1990s, peritoneal metastasis was considered as terminal stage of the disease; in the late 1990s, selected patients with peritoneal metastasis were recategorized as local disease. Over the past two decades, the treatment of peritoneal involvement has transformed, and cytoreductive surgery plus intraperitoneal therapy have drastically altered the natural course of several malignancies. Areas covered: We performed a review of studies available on PubMed from 1 January 2014 to 31 July 2019 and the analysis of their reference citations. We describe the most current intraperitoneal chemotherapy opportunities in the treatment of gastric cancer: hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC), laparoscopic hyperthermic intraperitoneal chemotherapy (LHIPEC), neoadjuvant intraperitoneal and systemic chemotherapy (NIPS), LHIPEC + NIPS, extensive intraoperative peritoneal lavage (EIPL), early postoperative intraperitoneal chemotherapy (EPIC), and pressurized intraperitoneal aerosol chemotherapy (PIPAC). Expert opinion: Comprehensive treatment consisting of CRS combined with perioperative intraperitoneal/systemic chemotherapy can, today, be considered an effective strategy to improve the long-term survival of gastric cancer patients with peritoneal metastasis.

Optimizing outcomes for patients with gastric cancer peritoneal carcinomatosis

Peritoneal carcinomatosis (PC) from gastric cancer has traditionally been considered a terminal progression of the disease and is associated with poor survival outcomes. Positive peritoneal cytology similarly worsens the survival of patients with gastric cancer and treatment options for these patients have been limited. Recent advances in multimodality treatment regimens have led to innovative ways to care for and treat patients with this disease burden. One of these advances has been to use neoadjuvant therapy to try and convert patients with positive cytology or low-volume PC to negative cytology with no evidence of active peritoneal disease. These strategies include the use of neoadjuvant systemic chemotherapy alone, using neoadjuvant laparoscopic heated intraperitoneal chemotherapy (NLHIPEC) after systemic chemotherapy, or using neoadjuvant intraperitoneal and systemic chemotherapy (NIPS) in a bidirectional manner. For patients with higher volume PC, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been mainstays of treatment. When used together, CRS and HIPEC can improve overall outcomes in properly selected patients, but overall survival outcomes remain unacceptably low. The extent of peritoneal disease, commonly measured by the peritoneal carcinomatosis index (PCI), and the completeness of cytoreduction, has been shown to greatly impact outcomes in patients undergoing CRS and HIPEC. The uses of NLHIPEC and NLHIPEC plus NIPS have both been shown to decrease the PCI and thus increase the opportunity for complete cytoreduction. Newer therapies like pressurized intraperitoneal aerosol chemotherapy and immunotherapy, such as catumaxomab, along with improved systemic chemotherapeutic regimens, are being explored with great interest. There is exciting progress being made in the management of PC from gastric cancer and its' treatment is no longer futile.

Role of staging laparoscopy in the management of Pancreatic Duct Carcinoma (PDAC): Single-center experience from a tertiary hospital in Brazil

BACKGROUND

Proper staging is critical to the management of pancreatic ductal carcinoma (PDAC). Laparoscopy has been used to stage patients without gross metastatic disease with variable success.

OBJECTIVES

We aimed to identify the frequency of patients diagnosed by laparoscopy with occult metastatic disease. Also, we looked for variables related to a higher chance of occult metastasis.

METHODS

Patients with PDAC submitted to staging laparoscopy either immediately before pancreatectomy or as a separate procedure between January 2010 and December 2016 were included. None presented gross metastatic disease at initial staging. We used logistic regression to search for variables associated with metastatic disease.

RESULTS

The study population consisted of 63 patients. Among all patients, nine (16.7%) had occult metastases at laparoscopy. Unresectable tumor (Odds ratio = 18.0, P = 0.03), increasing tumor size (Odds ratio = 1.36, P = 0.01), and abdominal pain (Odds ratio = 5.6, P = 0.04) significantly predicted the risk of occult metastases in univariate analysis. In multivariate analysis, only tumor size predicted the risk of occult metastases.

CONCLUSION

Laparoscopy remains a valuable tool in PDAC staging. Patients with either large or unresectable tumors, or presenting with abdominal pain present the highest risk for occult intra-abdominal metastases.

Applying Precision Medicine to Ovarian Cancer: Proof-of-Principle for a "Molecular Second Look"

OBJECTIVES

The objectives of this study were to assess if targeted investigation for tumor-specific mutations by ultradeep DNA sequencing of peritoneal washes of ovarian cancer patients after primary surgical debulking and chemotherapy, and clinically diagnosed as disease free, provides a more sensitive and specific method to assess actual treatment response and tailor future therapy and to compare this "molecular second look" with conventional cytology and histopathology-based findings.

METHODS/MATERIALS

We identified 10 patients with advanced-stage, high-grade serous ovarian cancer who had undergone second-look laparoscopy and for whom DNA could be isolated from biobanked paired blood, primary and recurrent tumor, and second-look peritoneal washes. A targeted 56 gene cancer-relevant panel was used for next-generation sequencing (average coverage, >6500×). Mutations were validated using either digital droplet polymerase chain reaction (ddPCR) or Sanger sequencing.

RESULTS

A total of 25 tumor-specific mutations were identified (median, 2/patient; range, 1-8). TP53 mutations were identified in at least 1 sample from all patients. All 5 pathology-based second-look positive patients were confirmed positive by molecular second look. Genetic analysis revealed that 3 of the 5 pathology-based negative second looks were actually positive. In the 2 patients, the second-look mutations were present in either the original primary or recurrent tumors. In the third, 2 high-frequency, novel frameshift mutations in MSH6 and HNF1A were identified.

CONCLUSIONS

The molecular second look detects tumor-specific evidence of residual disease and provides genetic insight into tumor evolution and future recurrences beyond standard pathology. In the precision medicine era, detecting and genetically characterizing residual disease after standard treatment will be invaluable for improving patient outcomes.