Intraperitoneal chemotherapy for peritoneal metastases of gastric origin: a systematic review and meta-analysis.

BACKGROUND: Gastric cancer with peritoneal metastases is associated with a dismal prognosis. Normothermic catheter-based intraperitoneal chemotherapy and normothermic pressurized intraperitoneal aerosol chemotherapy (PIPAC) are methods to deliver chemotherapy intraperitoneally leading to higher intraperitoneal concentrations of cytotoxic drugs compared to intravenous administration. We reviewed the effectiveness and safety of different methods of palliative intraperitoneal chemotherapy. METHODS: Embase, MEDLINE, Web of Science and Cochrane were searched for articles studying the use of repeated administration of palliative intraperitoneal chemotherapy in patients with gastric cancer and peritoneal metastases, published up to January 2024. The primary outcome was overall survival. RESULTS: Twenty-three studies were included, representing a total of 999 patients. The pooled median overall survival was 14.5 months. The pooled hazard ratio of the two RCTs using intraperitoneal paclitaxel and docetaxel favoured the intraperitoneal chemotherapy arm. The median overall survival of intraperitoneal paclitaxel, intraperitoneal docetaxel and PIPAC with cisplatin and doxorubicin were respectively 18.4 months, 13.2 months and 9.0 months. All treatment methods had a relatively safe toxicity profile. Conversion surgery after completion of intraperitoneal therapy was performed in 16% of the patients. CONCLUSIONS: Repeated intraperitoneal chemotherapy, regardless of method of administration, is safe for patients with gastric cancer and peritoneal metastases. Conversion surgery after completion of the intraperitoneal chemotherapy is possible in a subset of patients.

Hyperthermic intraperitoneal chemotherapy in colorectal cancer.

BACKGROUND: This study evaluated the efficacy of hyperthermic intraperitoneal chemotherapy (HIPEC) in colorectal cancer with peritoneal metastases (pmCRC) in a large international data set of patients. PATIENTS AND METHODS: Patients with pmCRC from 39 centres who underwent cytoreductive surgery with HIPEC between 1991 and 2018 were selected and compared for the HIPEC protocols received-oxaliplatin-HIPEC versus mitomycin-HIPEC. Following analysis of crude data, propensity-score matching (PSM) and Cox-proportional hazard modelling were performed. Outcomes of interest were overall survival (OS), recurrence-free survival (RFS) and the HIPEC dose-response effects (high versus low dose, dose intensification and double drug protocols) on OS, RFS and 90-day morbidity. Furthermore, the impact of the treatment time period was assessed. RESULTS: Of 2760 patients, 2093 patients were included. Median OS was 43 months (95% c.i. 41 to 46 months) with a median RFS of 12 months (95% c.i. 12 to 13 months). The oxaliplatin-HIPEC group had an OS of 47 months (95% c.i. 42 to 53 months) versus 39 months (95% c.i. 36 to 43 months) in the mitomycin-HIPEC group (P = 0.002), aHR 0.77, 95% c.i. 0.67 to 0.90, P < 0.001. The OS benefit persisted after PSM of the oxaliplatin-HIPEC group and mitomycin-HIPEC group (48 months (95% c.i. 42 to 59 months) versus 40 months (95% c.i. 37 to 44 months)), P < 0.001, aHR 0.78 (95% c.i. 0.65 to 0.94), P = 0.009. Similarly, matched RFS was significantly higher for oxaliplatin-HIPEC versus others (13 months (95% c.i. 12 to 15 months) versus 11 months (95% c.i. 10 to 12 months, P = 0.02)). High-dose mitomycin-HIPEC protocols had similar OS compared to oxaliplatin-HIPEC. HIPEC dose intensification within each protocol resulted in improved survival. Oxaliplatin + irinotecan-HIPEC resulted in the most improved OS (61 months (95% c.i. 51 to 101 months)). Ninety-day mortality in both crude and PSM analysis was worse for mitomycin-HIPEC. There was no change in treatment effect depending on the analysed time period. CONCLUSIONS: Oxaliplatin-based HIPEC provided better outcomes compared to mitomycin-based HIPEC. High-dose mitomycin-HIPEC was similar to oxaliplatin-HIPEC. The 90-day mortality difference favours the oxaliplatin-HIPEC group. A trend for dose-response between low- and high-dose HIPEC was reported.

The Role of Palliative Surgery in the Management of Acute Intestinal Obstruction Secondary to Peritoneal Carcinomatosis.

Introduction: Acute intestinal obstruction secondary to extensive peritoneal carcinomatosis is an end stage event. The role of palliative surgery in these patients is debatable in view of the anticipated severe complications and its doubtful role in achieving adequate palliation. The primary objective of our study was to evaluate the feasibility and ability of patients to resume oral nutrition after palliative surgery for acute intestinal obstruction due to peritoneal carcinomatosis. Patients and Methods: It is an observational study in which we retrospectively reviewed the data from a prospectively maintained clinical database of 40 patients. The predefined pre- and intraoperative variables were obtained. The immediate outcome variables like postoperative complications, length of hospital stay, and mortality were analyzed. The short-term outcomes at 3 months in the form of survival, ability to resume enteral nutrition were analyzed. Results: Among the 40 patients 18 were males and 22 females. Ovarian cancer was the most common primary (27.5%) in the study. Twelve patients had acute intestinal obstruction as their first presentation without any past events and 25 (62.5%) patients had been operated on previously or received adjuvant systemic treatment. The palliative surgical option was technically feasible in 37 (93.5%) patients. The median length of hospitalization for the patients who were discharged was 10 days with a range of 6-18 days. Six (15%) patients died in the postoperative period. Severe post-operative complications were seen in 9 (26.4%) patients. Among the patients (n=34) discharged 26 (76.4%) were alive at 3 months. In those who were alive, 21 (80.7%) of them were on some form of oral nutrition at 3 months. Conclusion: Palliative surgery in patients with acute intestinal obstruction secondary to peritoneal carcinomatosis is feasible with acceptable morbidity and mortality. The enteral nutrition can be restored in the majority of these patients.

Superiority of 18F-FAPI-42 PET/CT in the detection of primary tumor and management of appendiceal neoplasm to 18F-FDG PET/CT and CE-CT.

BACKGROUND: In the present study, we investigated the value of 18F-fibroblast-activation protein inhibitor (FAPI) positron emission tomography/computed tomography (18F-FAPI-42 PET/CT) to preoperative evaluations of appendiceal neoplasms and management for patients. METHODS: This single-center retrospective clinical study, including 16 untreated and 6 treated patients, was performed from January 2022 to May 2023 at Southern Medical University Nanfang Hospital. Histopathologic examination and imaging follow-up served as the reference standard. 18F-FAPI-42 PET/CT was compared to 18F-fluorodeoxyglucose (18F-FDG) PET/CT and contrast-enhanced CT (CE-CT) in terms of maximal standardized uptake value (SUVmax), diagnostic efficacy and impact on treatment decisions. RESULTS: The accurate detection of primary tumors and peritoneal metastases were improved from 28.6% (4/14) and 50% (8/16) for CE-CT, and 43.8% (7/16) and 85.0% (17/20) for 18F-FDG PET/CT, to 87.5% (14/16) and 100% (20/20) for 18F-FAPI-42 PET/CT. Compared to 18F-FDG PET/CT, 18F-FAPI-42 PET/CT detected more regions infiltrated by peritoneal metastases (108 vs. 43), thus produced a higher peritoneal cancer index (PCI) score (median PCI: 12 vs. 5, P < 0.01). 18F-FAPI-42 PET/CT changed the intended treatment plans in 35.7% (5/14) of patients compared to CE-CT and 25% (4/16) of patients compared to 18F-FDG PET/CT but did not improve the management of patients with recurrent tumors. CONCLUSIONS: The present study revealed that 18F-FAPI-42 PET/CT can supplement CE-CT and 18F-FDG PET/CT to provide a more accurate detection of appendiceal neoplasms and improved treatment decision making for patients.

Exosomal miR-493 suppresses MAD2L1 and induces chemoresistance to intraperitoneal paclitaxel therapy in gastric cancer patients with peritoneal metastasis.

Intraperitoneal (IP) chemotherapy with paclitaxel (PTX) for gastric cancer (GC) with peritoneal metastasis (PM) is considered a promising treatment approach, however, there are no useful biomarkers to predict the efficacy of IP therapy. We examined the association between intra-peritoneal exosomes, particularly exosomal micro-RNAs (exo-miRNAs), and IP-chemo sensitivity. MKN45 cells that were cultured with intra-peritoneal exosomes from patients who did not respond to IP therapy with PTX (IPnon-respond group) exhibited resistance to PTX compared with exosomes from responding patients (IPrespond group) (p = 0.002). A comprehensive search for exo-miRNAs indicated that miR-493 was significantly up-regulated in exosomes from the IPnon-respond group compared with those collected from the IPrespond group. The expression of miR-493 in PTX-resistant MKN45 cells (MKN45PTX-res) was higher compared with that in MKN45. In addition, MKN45PTX-res cells exhibited lower MAD2L1 gene and protein expression compared with MKN45. Finally, miR-493 enhancement by transfection of miR-493 mimics significantly down-regulated MAD2L1 expression in MKN45 cells and reduced PTX sensitivity. Our results suggest that intra-peritoneal exo-miR-493 is involved in chemoresistance to PTX by downregulating MAD2L1 in GC with PM. Exo-miR-493 may be a biomarker for chemoresistance and prognosis of GC patients with PM and may also be a promising therapeutic target.

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.

Single-incision laparoscopic surgery for benign multicystic mesothelioma of the peritoneum in a young man: A case report.

Benign multicystic peritoneal mesothelioma (BMPM) is a rare condition, particularly in men, and the preoperative diagnosis poses a challenge. Here, we present a case involving single-incision laparoscopic surgery (SILS) for BMPM in a 24-year-old man with a pelvic mass and a history of ulcerative colitis. Pelvic imaging revealed multifocal cysts, prompting the performance of SILS. The tumor was successfully resected with no residual lesions, and pathology confirmed the diagnosis of BMPM. This case represents the first documented instance of SILS being employed for BMPM in a man. BMPM, characterized by pelvic multifocal cysts, is a differential diagnosis, and SILS emerges as a viable option for both diagnosis and treatment.

Colorectal carcinoma peritoneal metastases-derived organoids: results and perspective of a model for tailoring hyperthermic intraperitoneal chemotherapy from bench-to-bedside.

BACKGROUND: Peritoneal metastases from colorectal cancer (CRCPM) are related to poor prognosis. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been reported to improve survival, but peritoneal recurrence rates are still high and there is no consensus on the drug of choice for HIPEC. The aim of this study was to use patient derived organoids (PDO) to build a relevant CRCPM model to improve HIPEC efficacy in a comprehensive bench-to-bedside strategy. METHODS: Oxaliplatin (L-OHP), cisplatin (CDDP), mitomycin-c (MMC) and doxorubicin (DOX) were used to mimic HIPEC on twelve PDO lines derived from twelve CRCPM patients, using clinically relevant concentrations. After chemotherapeutic interventions, cell viability was assessed with a luminescent assay, and the obtained dose-response curves were used to determine the half-maximal inhibitory concentrations. Also, induction of apoptosis by different HIPEC interventions on PDOs was studied by evaluating CASPASE3 cleavage. RESULTS: Response to drug treatments varied considerably among PDOs. The two schemes with better response at clinically relevant concentrations included MMC alone or combined with CDDP. L-OHP showed relative efficacy only when administered at low concentrations over a long perfusion period. PDOs showed that the short course/high dose L-OHP scheme did not appear to be an effective choice for HIPEC in CRCPM. HIPEC administered under hyperthermia conditions enhanced the effect of chemotherapy drugs against cancer cells, affecting PDO viability and apoptosis. Finally, PDO co-cultured with cancer-associated fibroblast impacted HIPEC treatments by increasing PDO viability and reducing CASPASES activity. CONCLUSIONS: Our study suggests that PDOs could be a reliable in vitro model to evaluate HIPEC schemes at individual-patient level and to develop more effective treatment strategies for CRCPM.

Primary omental smooth muscle tumor in an adult male: a diagnostic dilemma for leiomyoma: a case report.

BACKGROUND: The greater omentum comprises peritoneal, adipose, vascular, and lymphoid tissues. Most omental malignancies are metastatic tumors, and the incidence of primary tumors is rare. We report on a prior omental smooth muscle tumor case in an adult male patient. CASE PRESENTATION: A 54-year-old Japanese male patient with no relevant medical history was diagnosed with an abdominal mass during a routine medical checkup. Subsequent contrast-enhanced computed tomography revealed a mass of approximately 3 cm in size in the greater omentum, and a laparotomy was performed. A 27 × 25 × 20 mm raised lesion was found in the omentum. Microscopically, spindle cells were observed and arranged in whorls and fascicles. Individual tumor cells had short spindle-shaped nuclei with slightly increased chromatin and were characterized by a slightly eosinophilic, spindle-shaped cytoplasm. The mitotic count was less than 1 per 50 high-power fields. The tumor cells showed positive immunoreactivity for α smooth muscle actin, HHF35, and desmin on immunohistochemical examination. The Ki-67 labeling index using the average method was 1.76% (261/14806). No immunoreactivity was observed for any of the other tested markers. We considered leiomyoma owing to a lack of malignant findings. However, primary omental leiomyoma has rarely been reported, and it can be difficult to completely rule out the malignant potential of smooth muscle tumors in soft tissues. Our patient was decisively diagnosed with a primary omental smooth muscle tumor considering leiomyoma. Consequently, the patient did not undergo additional adjuvant therapy and was followed up. The patient was satisfied with treatment and showed neither recurrence nor metastasis at the 13-month postoperative follow-up. DISCUSSION AND CONCLUSION: We encountered a primary smooth muscle tumor of the greater omentum with no histological findings suggestive of malignancy in an adult male patient. However, omental smooth muscle tumors are extremely difficult to define as benign, requiring careful diagnosis. Further case reports with long-term follow-up and case series are required to determine whether a true omental benign smooth muscle tumor (leiomyoma) exists. In addition, proper interpretation of the Ki-67 labeling index should be established. This case study is a foundation for future research.

High mobility group box 1 mediates inflammatory responses in malignant peritoneal mesothelioma.

BACKGROUND: Serum high mobility group box 1 (HMGB1) serves as a diagnostic biomarker for malignant peritoneal mesothelioma (MPM) patients, yet its diagnostic significance within MPM tumor tissues remains uncertain. This study aims to elucidate the roles of HMGB1 in MPM. METHODS: HMGB1 expression analysis was conducted in both tumor and adjacent non-cancerous tissues collected from MPM patients. The two-year follow-up of MPM patients commenced from the diagnosis date. Inflammatory cytokine analysis was performed on these tissues, and Pearson correlation coefficient analysis was applied to examine variable relationships. In vitro assays included constructing an HMGB1 knockdown cell line, assessing cell viability, apoptosis, and inflammatory cytokine levels to delineate HMGB1's roles in MPM. RESULTS: HMGB1 overexpression was observed in MPM tumor tissues, particularly in stages III-IV. Diagnostic implications of HMGB1 for MPM were evident, augmenting its diagnostic value. HMGB1 overexpression correlated with diminished survival rates. Positive correlations existed between inflammatory cytokines and HMGB1 in MPM tumor tissues and cell lines. Suppression of HMGB1 regulated cell growth and apoptosis in MPM cell lines. CONCLUSION: HMGB1 exhibits diagnostic potential for MPM and modulates inflammatory responses within the disease context.

Long term survival outcomes of surgery combined with hyperthermic intraperitoneal chemotherapy for perforated low-grade appendiceal mucinous neoplasms: A multicenter retrospective study.

BACKGROUND: Low-grade appendiceal mucinous neoplasms (LAMN) are very rare, accounting for approximately 0.2%-0.5% of gastrointestinal tumors. We conducted a multicenter retrospective study to explore the impact of different surgical procedures combined with HIPEC on the short-term outcomes and long-term survival of patients. METHODS: We retrospectively analyzed the clinicopathological data of 91 LAMN perforation patients from 9 teaching hospitals over a 10-year period, and divided them into HIPEC group and non-HIPEC group based on whether or not underwent HIPEC. RESULTS: Of the 91 patients with LAMN, 52 were in the HIPEC group and 39 in the non-HIPEC group. The Kaplan-Meier method predicted that 52 patients in the HIPEC group had 5- and 10-year overall survival rates of 82.7% and 76.9%, respectively, compared with predicted survival rates of 51.3% and 46.2% for the 39 patients in the non-HIPEC group, with a statistically significant difference between the two groups (χ2 = 10.622, p = 0.001; χ2 = 10.995, p = 0.001). Compared to the 5-year and 10-year relapse-free survival rates of 75.0% and 65.4% in the HIPEC group, respectively, the 5-year and 10-year relapse-free survival rates of 48.7% and 46.2% in the non-HIPEC group were significant different between the two outcomes (χ2 = 8.063, p = 0.005; χ2 = 6.775, p = 0.009). The incidence of postoperative electrolyte disturbances and hypoalbuminemia was significantly higher in the HIPEC group than in the non-HIPEC group (p = 0.023; p = 0.044). CONCLUSIONS: This study shows that surgery combined with HIPEC can significantly improve 5-year and 10-year overall survival rates and relapse-free survival rates of LAMN perforation patients, without affecting their short-term clinical outcomes.

Extremely high peritoneal cancer index in colorectal peritoneal metastases demonstrates safety and overall survival benefit in selected patients undergoing cytoreductive surgery and heated intraperitoneal chemotherapy.

BACKGROUND: Colorectal peritoneal metastases are a devastating consequence of colorectal cancer (CRC) with extremely poor prognosis. Patients that can undergo complete cytoreduction by cytoreductive surgery and heated intraperitoneal chemotherapy (CRS/HIPEC) have a markedly improved overall survival. Traditionally, patients with extremely high peritoneal cancer index (PCI), PCI >20, are not offered CRS/HIPEC. METHODS: We performed a retrospective analysis of our prospectively maintained CRS/HIPEC database and evaluated all patients with CRC peritoneal metastases between 2012 and 2022. We divided the cohorts between those with low operative PCI (PCI<20) and high operative PCI (PCI =>20). We examined demographic, clinicopathologic data, perioperative, and oncological outcomes between the cohorts. RESULTS: Of the 691 patients who underwent CRS/HIPEC, 289 were evaluable with CRC metastases, 234 with PCI <20 and 43 with PCI => 20. Median radiologic preoperative and operative PCI was 4 and 10 versus 7 and 24.5 in the low and high PCI cohorts, respectively. Operative time was longer (6 vs. 4 h) and blood loss higher (500 vs. 400 mL) in the high PCI cohort. All other demographic, clinicopathological, and operative characteristics were similar. Median disease free survival (DFS) was longer in the low PCI cohort (11.5 vs. 7 months) but overall survival (OS) showed benefit (41.3 vs. 31.8 months), (p = 0.001 and p = 0.189, respectively), comparatively with an only chemotherapy strategy. CONCLUSIONS: Appropriately selected patients with CRC metastases and extremely high PCI demonstrate similar perioperative safety outcomes in experienced tertiary referral centers. Despite a shorter median DFS, these carefully selected patients demonstrated similar median OS.

Neoadjuvant chemotherapy does not improve survival for patients with high volume colorectal peritoneal metastases undergoing cytoreductive surgery.

BACKGROUND: Colorectal peritoneal metastases (CRPM) affects 15% of patients at initial colorectal cancer diagnosis. Neoadjuvant chemotherapy (NAC) prior to cytoreductive surgery (CRS) has been demonstrated to be a safe and feasible option, however there is limited data describing its efficacy in advanced peritoneal disease. This study evaluated the effect of NAC on survival in patients with high volume CRPM undergoing CRS with or without HIPEC. METHODS: A retrospective review of all patients who underwent CRS with or without HIPEC for CRPM from 2004 to 2019 at our institution was performed. The cohort was divided based on peritoneal carcinomatosis index (PCI) at surgery: Low Volume (PCI ≤ 16) and High Volume (PCI > 16). RESULTS: A total of 326 patients underwent CRS with HIPEC for CRPM. There were 39 patients (12%) with High Volume disease, and 15 of these (38%) received NAC. Patients with High Volume disease had significantly longer operating time, lower likelihood of complete macroscopic cytoreduction (CC-0 score), longer intensive care unit length of stay and longer hospital stay compared to Low Volume disease. In High Volume disease, the NAC group had a significantly shorter median survival of 14.4 months compared to 23.8 months in the non-NAC group (p = 0.046). CONCLUSION: Patients with High Volume CRPM achieved good median survival following CRS with HIPEC, which challenges the current PCI threshold for offering CRS. The use of NAC in this cohort did not increase perioperative morbidity but was associated with significantly shorter median survival compared to upfront surgery.

68Ga-FAPI-04 positron emission tomography/CT and laparoscopy for the diagnosis of occult peritoneal metastasis in newly diagnosed locally advanced gastric cancer: study protocol of a single-centre prospective cohort study.

INTRODUCTION: Accurate baseline clinical staging is critical to inform treatment decision-making for patients with gastric cancers. Peritoneal metastasis (PM) is the most common form of metastasis in gastric cancer and mainly diagnosed by diagnostic laparoscopy and peritoneal lavage evaluation. However, diagnostic laparoscopy is invasive and less cost-effective. It is urgent to develop a safe, fast and non-invasive functional imaging method to verify the peritoneal metastasis of gastric cancer. The aim of our study was to evaluate the proportion of patients in whom 68Ga-FAPI-04 positron emission tomography/CT (PET/CT) led to a change in treatment strategy and to assess the diagnostic accuracy of 68Ga-FAPI-04 PET/CT for the detection of occult peritoneal metastasis compared with laparoscopic exploration. METHODS AND ANALYSIS: In this single-centre, prospective diagnostic test accuracy study, a total of 48 patients with locally advanced gastric or gastro-oesophageal junction adenocarcinoma (cT4a-b, N0-3, M0, based on CT images) who are considering radical tumour surgery will be recruited. All participants will undergo 68Ga-FAPI-04 PET/CT before the initiation of laparoscopic exploration. The primary outcome is the proportion of patients with occult peritoneal metastatic lesions detected by 68Ga-FAPI-04 PET/CT, leading to a change in therapy strategy. The secondary outcomes include the diagnostic performance of 68Ga-FAPI-04 PET/CT for occult peritoneal metastasis, including sensitivity, specificity, accuracy, positive predictive value and negative predictive value. ETHICS AND DISSEMINATION: The study protocol was approved by the Ethics Committee of West China Hospital, Sichuan University (2022-1484). Study results will be presented at public and scientific conferences and in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ChiCTR2300067591.

Genomic characterization and detection of potential therapeutic targets for peritoneal mesothelioma in current practice.

Peritoneal mesothelioma (PeM) is an aggressive tumor with limited treatment options. The current study aimed to evaluate the value of next generation sequencing (NGS) of PeM samples in current practice. Foundation Medicine F1CDx NGS was performed on 20 tumor samples. This platform assesses 360 commonly somatically mutated genes in solid tumors and provides a genomic signature. Based on the detected mutations, potentially effective targeted therapies were identified. NGS was successful in 19 cases. Tumor mutational burden (TMB) was low in 10 cases, and 11 cases were microsatellite stable. In the other cases, TMB and microsatellite status could not be determined. BRCA1 associated protein 1 (BAP1) mutations were found in 32% of cases, cyclin dependent kinase inhibitor 2A/B (CDKN2A/B) and neurofibromin 2 (NF2) mutations in 16%, and ataxia-telangiectasia mutated serine/threonine kinase (ATM) in 11%. Based on mutations in the latter two genes, potential targeted therapies are available for approximately a quarter of cases (i.e., protein kinase inhibitors for three NF2 mutated tumors, and polyADP-ribose polymerase inhibitors for two ATM mutated tumors). Extensive NGS analysis of PeM samples resulted in the identification of potentially effective targeted therapies for about one in four patients. Although these therapies are currently not available for patients with PeM, ongoing developments might result in new treatment options in the future.

Adipose-derived stem cells promote glycolysis and peritoneal metastasis via TGF-ß1/SMAD3/ANGPTL4 axis in colorectal cancer.

Peritoneal metastasis, the third most common metastasis in colorectal cancer (CRC), has a poor prognosis for the rapid progression and limited therapeutic strategy. However, the molecular characteristics and pathogenesis of CRC peritoneal metastasis are poorly understood. Here, we aimed to elucidate the action and mechanism of adipose-derived stem cells (ADSCs), a prominent component of the peritoneal microenvironment, in CRC peritoneal metastasis formation. Database analysis indicated that ADSCs infiltration was increased in CRC peritoneal metastases, and high expression levels of ADSCs marker genes predicted a poor prognosis. Then we investigated the effect of ADSCs on CRC cells in vitro and in vivo. The results revealed that CRC cells co-cultured with ADSCs exhibited stronger metastatic property and anoikis resistance, and ADSCs boosted the intraperitoneal seeding of CRC cells. Furthermore, RNA sequencing was carried out to identify the key target gene, angiopoietin like 4 (ANGPTL4), which was upregulated in CRC specimens, especially in peritoneal metastases. Mechanistically, TGF-ß1 secreted by ADSCs activated SMAD3 in CRC cells, and chromatin immunoprecipitation assay showed that SMAD3 facilitated ANGPTL4 transcription by directly binding to ANGPTL4 promoter. The ANGPTL4 upregulation was essential for ADSCs to promote glycolysis and anoikis resistance in CRC. Importantly, simultaneously targeting TGF-ß signaling and ANGPTL4 efficiently reduced intraperitoneal seeding in vivo. In conclusion, this study indicates that tumor-infiltrating ADSCs promote glycolysis and anoikis resistance in CRC cells and ultimately facilitate peritoneal metastasis via the TGF-ß1/SMAD3/ANGPTL4 axis. The dual-targeting of TGF-ß signaling and ANGPTL4 may be a feasible therapeutic strategy for CRC peritoneal metastasis.

Laparoscopic extraction of a symptomatic upper abdominal pedunculated parietal peritoneal lipoma arising intermittent abdominal pain: a case report.

INTRODUCTION: Lipomas arising in the parietal peritoneum are rare, and some of them cause abdominal pain due to torsion of the pedunculated peritoneum. We encountered a case of parietal peritoneal lipoma arising upper peritoneum. In this report, we describe the detail of clinical presentation and discuss its potential pathogenesis and treatment strategy. CASE PRESENTATION: 45 year-old Japanese female patient presented with long-lasting intermittent pain in the left upper abdominal region. Abdominal imaging showed a well-defined fatty mass measuring 40 mm in size, suggesting a parietal peritoneal lipoma. Laparoscopy revealed a tumor with a twisted peduncle; however, no adhesion of the surrounding tissues and ischemic changes were visible. The tumor was easily removed by dissection of the tumor pedicle. CONCLUSION: Parietal peritoneal lipoma often shows pedunculated form and it causes abdominal pain by the torsion of tumor pedicle. Therefore, this type of lipoma should be considered a more aggressive surgery.

Transhepatic Bromelain and Acetylcysteine for Treatment of Posterior Gastric Pseudomyxoma Peritonei: A Case Report.

BACKGROUND/AIM: Pseudomyxoma peritonei (PMP) is a rare condition characterized by diffuse spread of mucinous tumors within the peritoneal cavity. Traditional treatment modalities, such as cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are challenging in cases of recurrent disease, owing to anatomical complexities and increasing morbidity and mortality risk. BromAc® has emerged as a novel, targeted therapy for PMP with evidence for intra-tumoral administration to break down mucin deposits. CASE REPORT: We present a 70-year-old female with confirmed diagnosis of symptomatic appendiceal PMP situated behind the stomach, refractory to prior CRS and HIPEC. Transhepatic intra-tumor injection of BromAc® was performed, guided by imaging, with catheter placement into the posterior gastric mucinous tumor. The procedure was well-tolerated, and post-treatment imaging revealed a significant 40% reduction in tumor burden. The patient had fever on cycle days two and three, which self-resolved and septic screen performed was negative. Following BromAc® administration, the patient demonstrated improvement in symptoms and quality of life. CONCLUSION: This case highlights the potential efficacy and safety of transhepatic administration of BromAc® for the treatment of recurrent PMP behind the stomach. The targeted delivery of BromAc® directly into a mucinous tumor via the transhepatic route offers a minimally invasive alternative for cases where traditional surgical interventions pose challenges. However, further research and clinical trials are warranted to validate the broader applicability of this novel approach, assess long-term outcomes, and optimize procedural parameters for enhanced therapeutic outcomes in PMP treatment.

Repeat cytoreductive surgery with HIPEC for colorectal peritoneal metastases: a systematic review.

BACKGROUND: Colorectal peritoneal metastases (CRPM) are present in 10-20% of patients at the time of their initial cancer diagnosis, and affects over 20% of those who develop colorectal cancer recurrence. Cytoreductive surgery (CRS) with HIPEC is firmly established as the optimal surgical treatment, but there is very little known about the benefit of repeat or iterative CRS. The aim of this review is to provide a systematic evaluation of the perioperative complications, survival outcomes and quality of life in patients undergoing repeat CRS with HIPEC for CRPM. METHODS: A systematic review of PubMed, Ovid MEDLINE, EMBASE, Scopus and Cochrane databases was performed to identify all studies that reported outcomes for repeat CRS with or without HIPEC for CRPM. RESULTS: Four hundred and ninety-three manuscripts were screened, and 15 retrospective studies were suitable for inclusion. Sample sizes ranged from 2 to 30 participants and comprised a total of 229 patients. HIPEC was used in all studies, but exact rates were not consistently stated. Perioperative morbidity was reported in four studies, between 16.7% and 37.5%. Nine studies reported mortality rate which was consistently 0%. The median overall survival after repeat CRS ranged from 20 to 62.6 months. No studies provided quality of life metrics. CONCLUSION: Repeat CRS for CRPM has perioperative morbidity and mortality rates comparable to initial CRS, and offers a potential survival benefit in selected patients. There is however limited high-quality data in the literature.

[Call for attention to the value and challenge of liquid biopsy in diagnosis and treatment for peritoneal metastasis of gastric cancer].

Peritoneal metastasis is the common route of metastasis in gastric cancer and is a major cause of death in advanced gastric cancer. Early intervention with comprehensive treatment can effectively improve the prognosis of some patients with peritoneal metastasis. However, early peritoneal metastasis in gastric cancer is predominantly micro-metastasis, which cannot be effectively evaluated by imaging studies. Moreover, the detection of disseminated cancer cells in peritoneal lavage suffers from a low detection rate and significant heterogeneity. In recent years, the development and application of new liquid biopsy technologies such as circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) have provided new means to assess potential peritoneal metastasis at the cellular and molecular levels, gradually becoming research hotspots in this field. This review will summarize the relevant progress of liquid biopsy in peritoneal metastasis, which holds significant importance for improving the prognosis of gastric cancer patients in China.