Effectiveness of peritoneal lavage fluid circulating tumour cells and circulating tumour DNA in the prediction of metachronous peritoneal metastasis of gastric cancer (pT4NxM0/pT1-3N+M0) after radical resection: protocol of a prospective single-centre clinical study.

BACKGROUND: Gastric cancer (GC) is the fourth leading cause of cancer mortality worldwide. Peritoneal metastasis (PM) is a significant cause of death in patients with GC, and presents a major challenge in clinical diagnosis and treatment. Predicting the occurrence of PM in high-risk patients, and diagnosing and treating PM in advance to improve patient survival, remains an unsolved problem in clinical practice. Given the low positive rate of cytology and difficulty in diagnosing occult PM, new molecular markers and detection technologies for early diagnosis require urgent validation. The primary objective of this study is to observe and evaluate the predictive effect of intraoperative peritoneal lavage fluid (PLF) circulating tumour cells (CTC) and circulating tumour DNA (ctDNA) levels in patients with pT4NxM0/pT1-3N+M0 GC on metachronous PM after R0 resection. METHODS AND ANALYSIS: This prospective single-centre clinical study is conducted at Renji Hospital, Shanghai Jiao Tong University School of Medicine. In this study, 200 cases of patients with pT4NxM0/pT1-3N+M0 gastric adenocarcinoma older than 18 years will be screened. Participants will undergo intraoperative PLF CTC and ctDNA testing and will be followed up for 2 years, with imaging assessments performed every 3-6 months until PM occurrs. The primary outcome is the incidence of PM 1 year after surgery, which will be estimated using Clopper-Pearson method, with 95% CIs calculated and compared between groups. Secondary outcome include the incidence of PM 2 years after surgery, overall survival and disease progression. Data will be analysed using the Kaplan-Meier method and the log-rank test. ETHICS AND COMMUNICATION: Informed consent has been obtained from all subjects. This protocol has been approved by the Ethics Committee of Renji Hospital, Shanghai Jiao Tong University School of Medicine (LY2023-142-B). The findings will be disseminated through peer-reviewed manuscripts, reports and presentations. TRIAL REGISTRATION NUMBER: ChiCTR2300074910.

Use of Diagnostic Laparoscopy and Peritoneal Washings for Pancreatic Cancer.

Pancreatic adenocarcinoma is an aggressive malignancy that often presents with advanced disease. Accurate staging is essential for treatment planning and shared decision-making with patients. Staging laparoscopy is a minimally invasive procedure that can detect radiographically occult metastatic disease. Its routine use with the collection of peritoneal washings in patients with pancreatic cancer remains controversial. We, herein, review the current literature concerning staging laparoscopy and peritoneal washings in patients with pancreatic cancer.

Peritoneal washing cytology status as a crucial prognostic determinant in patients with localized pancreatic ductal adenocarcinoma who underwent curative-intent resection following preoperative chemoradiotherapy.

BACKGROUND: Prognostic implications of peritoneal washing cytology (CY) in patients with localized pancreatic ductal adenocarcinoma (PDAC) undergoing surgical resection following preoperative chemoradiotherapy (CRT) remain unclear. This study aimed to elucidate the prognostic significance and predictors of a positive CY status (CY+) after preoperative CRT. METHODS: Clinical data from 141 patients with localized PDAC who underwent curative-intent resection after preoperative CRT were retrospectively analyzed to examine the association between CY+ and clinicopathological factors and survival. RESULTS: CY+ was observed in six patients (4.3%). The CY+ group exhibited significantly higher preoperative serum levels of CA19-9 and a substantially greater incidence of tumor location in the pancreatic body or tail, along with pathological invasion to the anterior pancreatic capsule, than the CY- group. The CY+ group had a significantly higher incidence of peritoneal recurrence compared with the CY- group (83.3% vs. 18.5%, p = 0.002). Overall survival (OS) and recurrence-free survival (RFS) after surgery were significantly shorter in the CY+ group than in the CY- group (CY+ vs. CY-: 18.3 vs. 46.2 months, p = 0.001, and 8.9 vs. 17.7 months, p = 0.009, respectively). Multivariate analyses identified CY+ as an independent prognostic factor for worse OS (hazard ratio 5.00, 95% confidence interval 1.03-12.31) and RFS (hazard ratio 2.58, 95% confidence interval 1.04-6.43). Local invasion grade on imaging before CRT, limited histological response to CRT, and absence of adjuvant chemotherapy were independent predictors of worse OS and RFS. CONCLUSION: Despite the relatively low incidence of CY+ after preoperative CRT, it emerged as an independent prognostic factor in patients with localized PDAC undergoing curative-intent resection following preoperative CRT.

Molecular diagnosis for detecting KRAS mutation in peritoneal washing fluid of pancreatic ductal adenocarcinoma.

Positive peritoneal washing cytology is an indicator of poor prognosis in patients with pancreatic ductal adenocarcinoma (PDAC); however, its sensitivity is relatively low. This study evaluated the performance of peptide nucleic acid (PNA)-directed PCR clamping as a molecular-based peritoneal washing cytology for sensitive detection of KRAS mutation in PDAC. Intraoperative peritoneal washing fluid (IPWF) obtained from patients with PDAC who underwent surgery was analyzed. PNA-directed PCR clamping was performed on DNA extracted from IPWF. Among 54 patients enrolled, threshold cycle (Ct) was significantly lower in patients with positive peritoneal washing cytology than in those with negative peritoneal washing cytology (P < 0.001) and in patients with peritoneal dissemination than in those without peritoneal dissemination (P < 0.01). The optimal Ct cut-off to predict KRAS mutations in IPWF was 36.42 based on a receiver operating characteristic curve. The sensitivity, specificity, and accuracy for molecular diagnosis were 100%, 80.0%, and 85.2%, respectively. Peritoneal dissemination recurrence was significantly more frequent in patients with a positive molecular diagnosis than in those with a negative diagnosis (38.9 vs. 8.0%, P = 0.013). The genomic approach might be clinically valuable for a more precise tumor cell detection in IPWF.

Deep learning predicts the 1-year prognosis of pancreatic cancer patients using positive peritoneal washing cytology.

Peritoneal washing cytology (CY) in patients with pancreatic cancer is mainly used for staging; however, it may also be used to evaluate the intraperitoneal status to predict a more accurate prognosis. Here, we investigated the potential of deep learning of CY specimen images for predicting the 1-year prognosis of pancreatic cancer in CY-positive patients. CY specimens from 88 patients with prognostic information were retrospectively analyzed. CY specimens scanned by the whole slide imaging device were segmented and subjected to deep learning with a Vision Transformer (ViT) and a Convolutional Neural Network (CNN). The results indicated that ViT and CNN predicted the 1-year prognosis from scanned images with accuracies of 0.8056 and 0.8009 in the area under the curve of the receiver operating characteristic curves, respectively. Patients predicted to survive 1 year or more by ViT showed significantly longer survivals by Kaplan-Meier analyses. The cell nuclei found to have a negative prognostic impact by ViT appeared to be neutrophils. Our results indicate that AI-mediated analysis of CY specimens can successfully predict the 1-year prognosis of patients with pancreatic cancer positive for CY. Intraperitoneal neutrophils may be a novel prognostic marker and therapeutic target for CY-positive patients with pancreatic cancer.

Prognostic analysis of peritoneal washing cytology during interval debulking surgery in advanced ovarian cancer.

BACKGROUND: Interval debulking surgery (IDS) following neoadjuvant chemotherapy is a treatment option for advanced ovarian cancer. Optimal surgery is required for better survival; however, while peritoneal washing cytology (PWC) has been identified as a prognostic factor, its comprehensive assessment during IDS remains unexplored. Therefore, we aimed to evaluate PWC efficacy during IDS, alongside other factors including residual disease and the modeled cancer antigen 125 (CA-125) ELIMination rate constant K (KELIM), by retrospectively reviewing the medical records of 25 patients with advanced ovarian cancer underwent neoadjuvant chemotherapy and IDS between January 2017 to June 2023. RESULTS: Twelve (48.0%) patients were PWC-positive, and the remainder were PWC-negative. PWC was performed at laparotomy during IDS, after which five (41.7%) PWC-positive and four (30.8%) PWC-negative patients received bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody, for maintenance treatment. Four (33.3%) PWC-positive and 10 (76.9%) PWC-negative patients received poly adenosine diphosphate (ADP)-ribose polymerase inhibitors. In patients who received bevacizumab and poly ADP-ribose polymerase inhibitors, overall survival and progression-free survival did not significantly differ between those who were PWC-positive and PWC-negative (p = 0.27 and 0.20, respectively). Progression-free survival significantly differed between those with favorable and unfavorable CA-125 KELIM (p = 0.02). Multivariate analysis indicated that optimal surgery and favorable CA-125 KELIM were associated with better progression-free survival (p < 0.01 and 0.02, respectively), with only optimal surgery associated with better overall survival (p = 0.04). CONCLUSIONS: A positive PWC at IDS was not associated with survival in advanced ovarian cancer. Our findings indicate that although PWC status at IDS should be one of the factors determining survival in patients with advanced ovarian cancer, recent improvements in maintenance therapy may make the combination of CA-125 KELIM and PWC status a more useful prognostic factor in selecting treatment after IDS. Further studies are needed to validate these results, highlighting the potential importance of maintenance treatment after IDS and the need for further research to validate the clinical significance of a positive PWC.

Positive peritoneal lavage fluid cytology based on isolation by size of epithelial tumor cells indicates a high risk of peritoneal metastasis.

Background: Peritoneal metastasis (PM) is the most prevalent type of metastasis in patients with gastric cancer (GC) and has an extremely poor prognosis. The detection of free cancer cells (FCCs) in the peritoneal cavity has been demonstrated to be one of the worst prognostic factors for GC. However, there is a lack of sensitive detection methods for FCCs in the peritoneal cavity. This study aimed to use a new peritoneal lavage fluid cytology examination to detect FCCs in patients with GC, and to explore its clinical significance on diagnosing of occult peritoneal metastasis (OPM) and prognosis. Methods: Peritoneal lavage fluid from 50 patients with GC was obtained and processed via the isolation by size of epithelial tumor cells (ISET) method. Immunofluorescence and fluorescence in situ hybridization (FISH) were used to identify FCCs expressing chromosome 8 (CEP8), chromosome 17 (CEP17), and epithelial cell adhesion molecule (EpCAM). Results: Using a combination of the ISET platform and immunofluorescence-FISH, the detection of FCCs was higher than that by light microscopy (24.0% vs. 2.0%). Samples were categorized into positive and negative groups, based on the expressions of CEP8, CEP17, and EpCAM. Statistically significant relationships were demonstrated between age (P = 0.029), sex (P = 0.002), lymphatic invasion (P = 0.001), pTNM stage (P = 0.001), and positivity for FCCs. After adjusting for covariates, patients with positive FCCs had lower progression-free survival than patients with negative FCCs. Conclusion: The ISET platform highly enriched nucleated cells from peritoneal lavage fluid, and indicators comprising EpCAM, CEP8, and CEP17 confirmed the diagnosis of FCCs. As a potential detection method, it offers an opportunity for early intervention of OPM and an extension of patient survival.

Prediction of peritoneal free cancer cells in gastric cancer patients by golden-angle radial sampling dynamic contrast-enhanced magnetic resonance imaging. / ç£å ±æŒ¯é‡‘è§’å¾„å‘é‡‡æ ·åŠ¨æ€å¢žå¼ºæˆåƒé¢„æµ‹èƒƒç™Œæ‚£è€ è ¹è ”æ¸¸ç¦»ç™Œç»†èƒž.

OBJECTIVES: Peritoneal free cancer cells can negatively impact disease progression and patient outcomes in gastric cancer. This study aimed to investigate the feasibility of using golden-angle radial sampling dynamic contrast-enhanced magnetic resonance imaging (GRASP DCE-MRI) to predict the presence of peritoneal free cancer cells in gastric cancer patients. METHODS: All enrolled patients were consecutively divided into analysis and validation groups. Preoperative magnetic resonance imaging (MRI) scans and perfusion were performed in patients with gastric cancer undergoing surgery, and peritoneal lavage specimens were collected for examination. Based on the peritoneal lavage cytology (PLC) results, patients were divided into negative and positive lavage fluid groups. The data collected included clinical and MR information. A nomogram prediction model was constructed to predict the positive rate of peritoneal lavage fluid, and the validity of the model was verified based on data from the verification group. RESULTS: There was no statistical difference between the proportion of PLC-positive cases predicted by GRASP DCE-MR and the actual PLC test. MR tumor stage, tumor thickness, and perfusion parameter Tofts-Ketty model volume transfer constant (Ktrans) were independent predictors of positive peritoneal lavage fluid. The nomogram model featured a concordance index (C-index) of 0.785 and 0.742 for the modeling and validation groups, respectively. CONCLUSIONS: GRASP DCE-MR could effectively predict peritoneal free cancer cells in gastric cancer patients. The nomogram model constructed using these predictors may help clinicians to better predict the risk of peritoneal free cancer cells being present in gastric cancer patients.

Intraperitoneal Irrigation Chemotherapy with Lobaplatin in Locally Advanced Gastric Cancer: A Special Type of Abdominal Chemotherapy.

BACKGROUND: This study evaluated the safety and efficiency of intraperitoneal irrigation chemotherapy with lobaplatin for the treatment of advanced gastric cancer (GC). METHODS: A total of 56 locally advanced GC patients (experimental group) who received intraoperative intraperitoneal irrigation chemotherapy in addition to undergoing radical D2 surgery were matched 1:1 based on 8 covariates to 56 patients without drug treatment (control group). Clinical data were collected and analyzed. RESULT: The two groups were well balanced in basic characteristics and had comparable clinical indices. All patients had similar time to first flatus (2.8 ± 0.3 vs. 2.9 ± 0.3 d, P = 0.076), time to first oral intake (3.5 ± 3.4 vs. 4.1 ± 4.6 d, P = 0.439), and duration of postoperative hospitalization (9.1 ± 3.2 vs. 9.6 ± 4.0 d, P = 0.446). There were no significant differences in postoperative complications including anastomotic and duodenal stump leakage, abdominal and anastomotic bleeding, seroperitoneum, and incision infection between the experimental and control groups (P > 0.05). The rates of chemotherapy-related side effects including allergic reaction, neurotoxicity, diarrhea, and nausea/vomiting were also similar between the two groups, and there were no abnormalities in leukocyte and platelet levels and liver and renal function during the first 5 days after surgery. CONCLUSION: Intraperitoneal irrigation chemotherapy with lobaplatin is safe for patients with advanced gastric cancer.

Impact of endoscopic ultrasound-guided tissue acquisition on prognosis and peritoneal lavage cytology in resectable or borderline resectable pancreatic ductal adenocarcinoma.

OBJECTIVES: This study aimed to evaluate the clinical impact of preoperative endoscopic ultrasound-guided tissue acquisition (EUS-TA) on the prognosis and incidence of positive peritoneal lavage cytology (PLC) during laparotomy or staging laparoscopy in patients with resectable (R) or borderline resectable (BR) pancreatic ductal adenocarcinoma (PDAC). METHODS: We retrospectively collected data from patients diagnosed with body and tail PDAC with/without EUS-TA at our hospital from January 2006 to December 2021. RESULTS: To examine the effect of EUS-TA on prognosis, 153 patients (122 in the EUS-TA group, 31 in the non-EUS-TA group) were analyzed. There was no significant difference in overall survival between the EUS-TA and non-EUS-TA groups after PDAC resection (P = 0.777). In univariate and multivariate analysis, preoperative EUS-TA was not identified as an independent factor related to overall survival after pancreatectomy [hazard ratio 0.96, 95 % confidence interval (CI) 0.54-1.70, P = 0.897]. Next, to examine the direct influence of EUS-TA on the results of PLC, 114 patients (83 in the EUS-TA group and 31 in the non-EUS-TA group) were analyzed. Preoperative EUS-TA was not statistically associated with positive PLC (odds ratio 0.73, 95 % CI 0.25-2.20, P = 0.583). After propensity score matching, overall survival and positive PLC were the same in both groups. CONCLUSIONS: EUS-TA had no negative impact on postoperative survival and PLC-positive rates in R/BR PDAC.

Clinical impact of high-quality testing for peritoneal lavage cytology in pancreatic cancer.

In pancreatic ductal adenocarcinoma (PDAC) patients, the importance of peritoneal lavage cytology, which indicates unresectability, remains controversial. This study sought to determine whether positive peritoneal lavage cytology (CY+) precludes pancreatectomy. Furthermore, we propose a novel liquid biopsy using peritoneal lavage fluid to detect viable peritoneal tumor cells (v-PTCs) with TelomeScan F35, a telomerase-specific replication-selective adenovirus engineered to express green fluorescent protein. Resectable cytologically or histologically proven PDAC patients (n = 53) were enrolled. CY was conducted immediately following laparotomy. The resulting fluid was examined by conventional cytology (conv-CY; Papanicolaou staining and MOC-31 immunostaining) and by the novel technique (Telo-CY; using TelomeScan F35). Of them, 5 and 12 were conv-CY+ and Telo-CY+, respectively. All underwent pancreatectomy. The two double-CY+ (conv-CY+ and Telo-CY+) patients showed early peritoneal recurrence (P-rec) postoperatively, despite adjuvant chemotherapy. None of the three conv-CY+ Telo-CY- patients exhibited P-rec. Six of the 10 Telo-CY+ conv-CY- patients (60%) relapsed with P-rec. Of the remaining 38 double-CY- [conv-CY-, Telo-CY-, conv-CY± (Class III)] patients, 3 (8.3%) exhibited P-rec. Although conv-CY+ status predicted poor prognosis and a higher risk of P-rec, Telo-CY was more sensitive for detecting v-PTC. Staging laparoscopy and performing conv-CY and Telo-CY are needed to confirm the indication for pancreatectomy.

Evaluation of laparoscopic peritoneal lavage for perforated diverticulitis: a national registry-based study.

BACKGROUND: Laparoscopic lavage (LPL) has been suggested for treatment of non-feculent perforated diverticulitis. In this observational study, the surgical treatment of diverticular disease in Sweden outside prospective trials was investigated. METHODS: This population-based study used the National Patient Register to identify all patients in Sweden with emergency admissions for diverticular disease, as defined by ICD codes from July 2014 to December 2020. Demographics, surgical procedures and outcomes were assessed. In addition, register data since 1997 were retrieved to assess co-morbidities, previous abdominal surgeries, and previous admissions for diverticular disease. RESULTS: Among 47 294 patients with emergency hospital admission, 2035 underwent LPL (427 patients) or sigmoid resection (SR, 1608 patients) for diverticular disease. The mean follow-up was 30.8 months. Patients selected for LPL were younger, healthier and with less previous abdominal surgery for diverticular disease than those in the SR group (P < 0.01). LPL was associated with shorter postoperative hospital stay (mean 9.4 versus 14.9 days, P < 0.001) and lower 30-day mortality (3.5% versus 8.7%, P < 0.001). Diverticular disease-associated subsequent surgery was more common in the SR group than the LPL group except during the first year (P < 0.001). LPL had a lower mortality rate during the study period (stratified HR 0.70, 95% c.i. 0.53-0.92, P = 0.023). CONCLUSION: Laparoscopic lavage constitutes a safe alternative to sigmoid resection for selected patients judged clinically to require surgery.

Diverticulitis is inflammation in pouches of the large bowel. Rarely, diverticulitis can lead to a bowel perforation causing peritonitis. Traditionally, it was treated by resection of the inflamed bowel with a stoma. A milder treatment has been proposed in which the abdomen is rinsed with saline laparoscopically and drained (laparoscopic lavage). This study aimed to examine the outcomes of laparoscopic lavage in Sweden. Our findings support the use of this method in younger and healthier patients with a history of no or only minor previous abdominal surgery.

Clinical Significance of Primary Tumor Resection in Perihilar Cholangiocarcinoma with Positive Peritoneal Lavage Cytology.

BACKGROUND: The prognostic impact of positive peritoneal lavage cytology (CY+) in patients with perihilar cholangiocarcinoma (PHC) remains unclear. The present study investigated the clinical significance of primary tumor resection of CY+ PHC. METHODS: We retrospectively evaluated 282 patients who underwent surgery for PHC between September 2002 and March 2022. The patients' clinicopathological characteristics and survival outcomes were compared between the CY negative (CY-) resected (n = 262), CY+ resected (n = 12), and CY+ unresected (n = 8) groups. Univariate and multivariate analyses were performed to identify prognostic factors for overall survival. RESULTS: The expected residual liver volume was significantly higher in the CY+ resected group (61%) than in the CY- resected (47%) and CY+ unresected (37%) groups (p = 0.004 and 0.007, respectively). The CY+ resected group had a higher administration rate of postoperative therapy than the CY- resected group (58% vs. 16%, p = 0.002). Overall survival of the CY+ resected group was similar to that of the CY- resected group (median survival time [MST] 44.5 vs. 44.6, p = 0.404) and was significantly better than that of the CY+ unresected group (MST 44.5 vs. 17.1, p = 0.006). CY positivity was not a prognostic factor according to a multivariate analysis in patients with primary tumor resection. CONCLUSIONS: The CY+ resected group showed better survival than the CY+ unresected group and a similar survival to that of the CY- resected group. Resection of the primary tumor with CY+ PHC may improve the prognosis in selected patients.

Improving diagnostic accuracy of identifying gastric cancer patients with peritoneal metastases: tumor-guided cell-free DNA analysis of peritoneal fluid.

Detection of peritoneal dissemination (PD) in gastric cancer (GC) patients remains challenging. The feasibility of tumor-guided cell-free DNA (cfDNA) detection in prospectively collected peritoneal fluid (ascites and peritoneal lavage) was investigated and compared to conventional cytology in 28 patients. Besides conventional cytology, next generation sequencing was performed on primary tumor DNA and cell-free DNA from peritoneal fluid. Patients were retrospectively grouped into: a positive group (with PD) and a negative group (without PD). Detectable mutations were found in the primary tumor of 68% (n = 19). Sensitivity of PD detection by tumor-guided cfDNA analysis was 91%, compared to 64% by conventional cytology. Within the positive group (n = 11), tumor-guided cfDNA was detected in all patients with ascites samples (4/4, 100%) and in 86% (6/7) of the lavage samples, opposed to 4/4 (100%) patients with ascites and 43% (3/7) with lavage by conventional cytology. Within the negative group (n = 8), conventional cytology was negative for all samples. In two patients, tumor-guided cfDNA was detected in peritoneal lavage fluid. Interestingly, these 2 patients developed PD within 6 months, suggesting a prognostic value of tumor-guided cfDNA detection. This study showed that tumor-guided cfDNA detection in peritoneal fluids of GC patients is feasible and superior to conventional cytology in detecting PD.

The Intraperitoneal Use of Cephazolin: A Novelty in the Prevention of Intra-abdominal Abscess after Laparoscopic Appendectomy in Children.

BACKGROUND: Laparoscopic appendectomy followed by postoperative intravenous (IV) antibiotics is the standard of care for acute appendicitis and postoperative prevention of intra-abdominal abscesses. The aim of or study was to determine if intraperitoneal irrigation with antibiotics could help prevent intra-abdominal abscess formation after laparoscopic appendectomy for complicated appendicitis in pediatric patients. METHODS: A retrospective study was conducted on consecutive pediatric patients with acute appendicitis who had appendectomy in our Pediatric Surgery Department between August 2020 and February 2022. We compared two groups with similar age and symptoms. The first group (A) was treated with the normal standard of care, i.e., laparoscopic appendectomy and postoperative IV antibiotic therapy. For the second group (B) intraperitoneal cefazoline irrigation was added at the end of the laparoscopic procedure. Postoperative intra-abdominal abscess was diagnosed with ultrasound examination, performed after clinical suspicion/abnormal blood test results. RESULTS: One hundred sixty patients (males:females 109:51; median age 10.5 years [range 3-17 years]) who had laparosopic appendectomy for complicated appendicitis were included, 82 in group A and 78 in group B. In the first 7 days after surgery, 18 patients in group and 5 in group B developed an intra-abdominal abscess (p < 0.005). Drains were positioned in 38 patients in group A vs. 9 in group B. One patient in group A had a different complication which was infection of the surgical incision. CONCLUSIONS: Intraperitoneal cefazoline irrigation at the end of the laparoscopic appendectomy in pediatric patients significantly reduces the formation of intra-abdominal abscesses.