Treatment Of Peritoneal Metastases Research Articles

Abstract LB264: Intracavitary gene therapy using miRNA-29b-encoding adeno-associated virus for peritoneal dissemination

Abstract INTRODUCTION: Peritoneal metastasis (PM) is the most critical prognostic factor in gastrointestinal cancers. Notably, the levels of microRNA (miR)-29b in peritoneal fluids have shown significant reduction in patients with PM of gastric cancer. Moreover, supplementation with miR-29b-incorporated exosomes has demonstrated the potential to suppress the formation of PM in a murine model. Nevertheless, given the technical demands associated with this method, we investigated the viability of intracavitary gene therapy as a potentially more advanced and practical approach for clinical implementation. METHODS: Using the calcium phosphate-based protocol, adeno-associated virus encoding miR-29b (AAV-miR-29b) was constructed, and its effects on mesothelial mesenchymal transition (MMT) were examined using peritoneal mesothelial cells (PMC) derived from human and murine omental tissues. PM was established in C57BL/6 mouse by intraperitoneal (IP) injection of a highly metastatic clone of gastric cancer cell, YTN16P or a pancreatic cancer cell, PAN02. In these syngeneic models, we examined the impact of IP injection of AAV-miR-29b at a single dose of 5 × 1010 vector genome (vg) on PM. RESULTS: AAV-miR-29b was effectively incorporated into PMCs, resulting in an increased level of miR-29b in extracellular vesicles produced by PMCs. Stimulation of PMCs with TGF-β1 (10ng/ml) decreased the expression of E-cadherin and increased vimentin and fibronectin expression along with enhanced migration activity. Importantly, all the changes were totally abrogated by AAV-miR-29b. Treatment of PMC with TGF-β1 notably increased the attachment of tumor cells, which was also entirely inhibited by AAV-miR-29b. Following IP administration of AAV-miR-29b in vivo, the expression level of miR-29b in peritoneal tissue and intraperitoneal exosomes increased significantly after two weeks. In both murine gastric and pancreatic cancer models, a single IP injection of AAV-miR-29b on day 0 led to a marked reduction in the number of PM nodules in the mesentery (gastric: 38.2 ± 18.7 vs. 8.0 ± 5.2, n=5, P < 0.05; pancreatic: 41.2 ± 7.5 vs. 14.4 ± 16.7, n=7, P < 0.001) and inhibited peritoneal fibrosis associated with PM. AAV-miR-29b elicits the same significant effects when administered on day3. Furthermore, when AAV-miR-29b was administered on day 7 in combination with low-dose Paclitaxel (PTX) (200 µg/mouse), a significant reduction in the number of PM nodules was observed, whereas the effect was not evident with PTX alone (35.8 ± 22.2, n=16 vs. 14.2 ± 16.0, n=12, P < 0.05). CONCLUSIONS: IP injection of AAV-miR-29b achieved robust transgene expression in PMCs and their exosomes, effectively suppressing MMT and peritoneal fibrosis leading to the inhibition of PM Intraabdominal gene therapy utilizing AAV containing tumor-suppressor miRNA could serve as a promising strategy for both the prevention and treatment of PM. Citation Format: Yuki Kaneko, Hideyuki Ohzawa, Yuki Kimura, Rei Takahashi, Misaki Matsumiya, Kohei Tamura, Yurie Futoh, Hideyo Miyato, Ryota Watano, Hiroaki Mizukami, Naohiro Sata, Joji Kitayama. Intracavitary gene therapy using miRNA-29b-encoding adeno-associated virus for peritoneal dissemination [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB264.

Initial Experience Using Laparoscopic HIPEC for Gastric Cancer with Peritoneal Metastasis: Safety and Outcomes.

Peritoneal metastases (PM) develop in approximately 20% of patients with gastric cancer (GC). For selected patients, treatment of PM with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has shown promising results. This report aims to describe the safety and perioperative outcomes of laparoscopic HIPEC for GC/PM. This retrospective cohort study evaluated patients who had GC and PM treated with laparoscopic HIPEC (2018-2022). The HIPEC involved cisplatin and mitomycin C (MMC) or MMC alone. The primary end point was perioperative safety. The 22 patients in this study underwent 27 procedures. The mean age was 58 ± 13 years. All the patients were Eastern Cooperative Oncology Group (ECOG) 0 or 1 (55 and 45%, respectively). Five patients underwent a second laparoscopic HIPEC, with a median of 126 days (interquartile range [IQR], 117-166 days) between procedures. The median peritoneal carcinomatosis index (PCI) was 4 (IQR, 2-9), and the median hospital stay was 2 days (IQR, 1-3 days). No 30-day readmissions or complications occurred. Eight patients (36%) underwent gastrectomy (CRS ± HIPEC). After an average follow-up period of 11 months, 7 (32%) of the 22 patients were alive. The median overall survival was 11 months (IQR, 195-739 days) from the initial procedure and 19.3 months (IQR, 431-1204 days) from the diagnosis. Laparoscopic HIPEC appears to be safe with minimal perioperative complications. Approximately one third of the patients undergoing initial laparoscopic HIPEC ultimately proceeded to cytoreduction and gastrectomy. Preliminary survival data from this highly selected cohort suggest that the addition of laparoscopic HIPEC to systemic chemotherapy does not compromise other treatment options. These initial results suggest that laparoscopic HIPEC may offer benefit to patients with GC and PM and aid in the selection of patients who may benefit from curative-intent resection.

Thermosensitive methyl-cellulose-based injectable hydrogel carrying oxaliplatin for the treatment of peritoneal metastasis in colorectal cancer.

Advanced colorectal cancer (CRC) with peritoneal metastasis (PM) is a highly aggressive malignancy with poor prognosis. Systematic chemotherapy and local treatments are the primary therapeutic approaches. However, systemic chemotherapy is limited by low accumulation of drugs at the tumor site and systemic toxicity. Local treatments include cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). However, CRS faces challenges related to incomplete tumor resection, while HIPEC is restricted by the uneven distribution of drugs and potential complications. Herein, a thermosensitive methyl-cellulose-based injectable hydrogel carrying oxaliplatin (OXA) was synthesized to improve this situation. Specifically, methyl cellulose (MC) coagulated into a hydrogel, and OXA was loaded into the MC hydrogel to construct the OXA-MC hydrogel. We explored the OXA-MC hydrogel for the treatment of PM in CRC. The results demonstrated that the OXA-MC hydrogel had favorable biocompatibility and thermo-sensitivity and could act as a local slow-release drug carrier. Moreover, in a CT-26 tumor-bearing model, it showed a remarkable anti-tumor effect by inhibiting proliferation and promoting apoptosis. Additionally, transcriptome analysis indicated that the OXA-MC hydrogel might be involved in the regulation of the PI3K-AKT signaling pathway. In summary, we successfully prepared the OXA-MC hydrogel and provided a valid approach in the treatment of PM in CRC, which lays a foundation for other PM treatments.

Colorectal Peritoneal Metastases State of Art

The presence of peritoneal metastasis (PM) in patients with colorectal cancer (CRC) is associated with an extremely poor prognosis. Recent developments in the field of treatment including new drugs, translational research for new molecules offer a future plan to achieved improved of Survival. On the other hand, numerous clinical trials regarding the role of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy have now opened new doors in peritoneal metastasis treatment. This review presents all the controversial data and options regarding this approach.

Peritoneal metastases from rare ovarian cancer treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC).

There are limited treatment options and no consensus on the management of advanced rare ovarian malignancies. Rare ovarian malignancies can present with peritoneal metastases (PM), featuring a similar presentation to more common ovarian subtypes. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is an effective treatment for PM of non-gynecologic origin and, recently, epithelial ovarian cancer. We evaluated the feasibility of CRS/HIPEC in the management of PM fromrare ovarian malignancies and report postoperative outcomes on these patients. A retrospective review of a single center, prospective database (1994-2021) was performed to identify patients with rare ovarian malignancies treated with CRS/HIPEC. Clavien-Dindo 90-day morbidity/mortality and Kaplan-Meier overall (OS) and progression-free survival (PFS) were analyzed. Of 44 patients identified, 28 underwent CRS/HIPEC. Six were aborted due to extensive disease. Histologic subtypes included: clear cell (5/28, 17.9 %), endometrioid (5/28, 17.9 %), granulosa cell (3/28, 10.7 %), low-grade serous (6/28, 21.4 %), mesonephric (1/28, 3.6 %), mucinous (6/28, 21.4 %), and small cell (2/28, 7.1 %) carcinomas. Eight (28.6 %) patients had primary and 20 (71.4 %) had recurrent disease. Median peritoneal cancer index (PCI) was 21 (IQR: 6-29). Complete cytoreduction (<2.5 mm residual disease) was achieved in 27/28 (96.4 %). Grade III/IV complications occurred in 9/28 (32.1 %) with one (3.6 %) mortality. After a median follow-up of 65.8months, 20 patients were alive. Five-year OS and PFS were 68.5 and 52.6 %, respectively. In patients with PM from rare ovarian malignancies, CRS/HIPEC is feasible and has an acceptable safety profile. Longer follow-up and multicenter trials are needed.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) with cisplatin and doxorubicin in combination with FOLFOX chemotherapy as a first-line treatment for gastric cancer patients with peritoneal metastases: single-arm phase II study

BackgroundGastric cancer (GC) remains among the most common and most lethal cancers worldwide. Peritoneum is the most common site for distant dissemination. Standard treatment for GC peritoneal metastases (PM) is a systemic therapy, but treatment outcomes remain very poor, with median overall survival ranging between 3-9 months. Thus, novel treatment methods are necessary. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is the most novel technique for intraperitoneal chemotherapy. Some preliminary data suggest PIPAC can achieve improved long-term outcomes in patients with GC PM, especially when used in combination with systemic chemotherapy. However, there is a lack of data from well-design prospective studies that would confirm the efficacy of PIPAC and systemic therapy combination for first-line treatment.MethodsThis study is an investigator-initiated single-arm, phase II trial to investigate the efficacy of PIPAC combined with systemic FOLFOX (5-fluorouracil, oxaliplatin, leucovorin) as a first-line treatment for GC PM. The study is conducted in 2 specialized GC treatment centers in Lithuania. It enrolls GC patients with histologically confirmed PM without prior treatment. The treatment protocol consists of PIPAC with cisplatin (10.5 mg/m2 body surface in 150 mL NaCl 0.9%) and doxorubicin (2.1 mg/m2 in 50 mL NaCl 0.9%) followed by 2 cycles of FOLFOX every 6–7 weeks. In total 3 PIPACs and 6 cycles of FOLFOX will be utilized. The primary outcome of the study is the objective response rate (ORR) according to RECIST v. 1.1 criteria (Eisenhauer et al., Eur J Cancer 45:228–47) in a CT scan performed 7 days after the 4th cycle of FOLFOX. Secondary outcomes include ORR after all experimental treatment, PIPAC characteristics, postoperative morbidity, histological and biochemical response, ascites volume, quality of life, overall survival, and toxicity.DiscussionThis study aims to assess PIPAC and FOLFOX combination efficacy for previously untreated GC patients with PM.Trial registrationNCT05644249. Registered on December 9, 2022.

CO2-Driven Nebulization of pH-Sensitive Supramolecular Polymers for Intraperitoneal Hydrogel Formation and the Treatment of Peritoneal Metastasis.

Because peritoneal metastasis (PM) from ovarian cancer is characterized by non-specific symptoms, it is often diagnosed at advanced stages. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) can be considered a promising drug delivery method for unresectable PM. Currently, the efficacy of intraperitoneal (IP) drug delivery is limited by the off-label use of IV chemotherapeutic solutions, which are rapidly cleared from the IP cavity. Hence, this research aimed to improve PM treatment by evaluating a nanoparticle-loaded, pH-switchable supramolecular polymer hydrogel as a controlled release drug delivery system that can be IP nebulized. Moreover, a multidirectional nozzle was developed to allow nebulization of viscous materials such as hydrogels and to reach an even IP gel deposition. We demonstrated that acidification of the nebulized hydrogelator solution by carbon dioxide, used to inflate the IP cavity during laparoscopic surgery, stimulated the in situ gelation, which prolonged the IP hydrogel retention. In vitro experiments indicated that paclitaxel nanocrystals were gradually released from the hydrogel depot formed, which sustained the cytotoxicity of the formulation for 10 days. Finally, after aerosolization of this material in a xenograft model of PM, tumor progression could successfully be delayed, while the overall survival time was significantly increased compared to non-treated animals.

Drug Distribution and Penetration of Foam-Based Intraperitoneal Chemotherapy (FBIC).

For decades, intraperitoneal chemotherapy (IPC) was used as a liquid solution for the treatment of peritoneal metastasis. Due to its advantageous physical properties, foam-based intraperitoneal chemotherapy (FBIC) was recently proposed as a treatment for peritoneal metastasis. For the first time, this study intends to examine the feasibility, expansion, drug distribution, and penetration of FBIC in vivo. Three swine received contrast-enhanced FBIC doxorubicin delivered using a bicarbonate carrier system. During the procedure, intraoperative blood analyses and periumbilical diameter, as well as foam distribution, penetration, and expansion of the FBIC were analyzed. The swine received an abdominal CT scan to evaluate the contrast distribution. Furthermore, a hematoxylin-eosin (HE) staining of peritoneal samples was performed, and fluorescence microscopy was conducted. FBIC was performed without complications. The periumbilical diameter peaked after 5 min and then decreased. Blood analyses showed changes in blood parameters, with a reduction in the pH levels of serum calcium and potassium. CT scan detected contrast-enhanced FBIC throughout the abdominal cavity. Fluorescence microscopy confirmed that all areas were exposed to doxorubicin and no pathologies were detected in the HE histology. Our preliminary results are quite encouraging and indicate that FBIC is a feasible approach. However, in order to discuss possible clinical applications, further studies are required to investigate the pharmacologic, pharmacodynamic, and physical properties of FBIC.

Effects of Hyperthermia and Hyperthermic Intraperitoneal Chemoperfusion on the Peritoneal and Tumor Immune Contexture.

Hyperthermia combined with intraperitoneal (IP) drug delivery is increasingly used in the treatment of peritoneal metastases (PM). Hyperthermia enhances tumor perfusion and increases drug penetration after IP delivery. The peritoneum is increasingly recognized as an immune-privileged organ with its own distinct immune microenvironment. Here, we review the immune landscape of the healthy peritoneal cavity and immune contexture of peritoneal metastases. Next, we review the potential benefits and unwanted tumor-promoting effects of hyperthermia and the associated heat shock response on the tumor immune microenvironment. We highlight the potential modulating effect of hyperthermia on the biomechanical properties of tumor tissue and the consequences for immune cell infiltration. Data from translational and clinical studies are reviewed. We conclude that (mild) hyperthermia and HIPEC have the potential to enhance antitumor immunity, but detailed further studies are required to distinguish beneficial from tumor-promoting effects.

Effects of laparoscopic hyperthermic intraperitoneal perfusion chemotherapy combined with intraperitoneal and systemic chemotherapy treatment in patients with untreated gastric cancer with peritoneal metastasis

Objective: To investigate the efficacy of laparoscopic hyperthermic intraperitoneal perfusion chemotherapy combined with intraperitoneal and systemic chemotherapy (HIPEC-IP-IV) in the treatment of peritoneal metastases from gastric cancer (GCPM). Methods: This was a descriptive case series study. Indications for HIPEC-IP-IV treatment include: (1) pathologically confirmed gastric or esophagogastric junction adenocarcinoma; (2) age 20-85 years; (3) peritoneal metastases as the sole form of Stage IV disease, confirmed by computed tomography, laparoscopic exploration, ascites or peritoneal lavage fluid cytology; and (4) Eastern Cooperative Oncology Group performance status 0-1. Contraindications include: (1) routine blood tests, liver and renal function, and electrocardiogram showing no contraindications to chemotherapy; (2) no serious cardiopulmonary dysfunction; and (3) no intestinal obstruction or peritoneal adhesions. According to the above criteria, data of patients with GCPM who had undergone laparoscopic exploration and HIPEC from June 2015 to March 2021 in the Peking University Cancer Hospital Gastrointestinal Center were analyzed, after excluding those who had received antitumor medical or surgical treatment. Two weeks after laparoscopic exploration and HIPEC, the patients received intraperitoneal and systemic chemotherapy. They were evaluated every two to four cycles. Surgery was considered if the treatment was effective, as shown by achieving stable disease or a partial or complete response and negative cytology. The primary outcomes were surgical conversion rate, R0 resection rate, and overall survival. Results: Sixty-nine previously untreated patients with GCPM had undergone HIPEC-IP-IV, including 43 men and 26 women; with a median age of 59 (24-83) years. The median PCI was 10 (1-39). Thirteen patients (18.8%) underwent surgery after HIPEC-IP-IV, R0 being achieved in nine of them (13.0%). The median overall survival (OS) was 16.1 months. The median OS of patients with massive or moderate ascites and little or no ascites were 6.6 and 17.9 months, respectively (P<0.001). The median OS of patients who had undergone R0 surgery, non-R0 surgery, and no surgery were 32.8, 8.0, and 14.9 months, respectively (P=0.007). Conclusions: HIPEC-IP-IV is a feasible treatment protocol for GCPM. Patients with massive or moderate ascites have a poor prognosis. Candidates for surgery should be selected carefully from those in whom treatment has been effective and R0 should be aimed for.

Genetically Engineered Artificial Exosome-Constructed Hydrogel for Ovarian Cancer Therapy.

Owing to the insidious onset of ovarian cancer, most patients are in the advanced stage with extensive peritoneal metastasis when they are diagnosed. Treatment of peritoneal metastasis from advanced ovarian cancer remains a significant challenge. Inspired by the massive macrophages in the peritoneal environment, here, we reported an artificial exosome-based peritoneal-localized hydrogel to domesticate peritoneal macrophages as the therapeutic target for realizing potent ovarian cancer therapy, where artificial exosomes derived from genetically sialic-acid-binding Ig-like lectin 10 (Siglec-10)-engineered M1-type macrophages were chemically designed as gelator. Upon triggering immunogenicity with X-ray radiation, our hydrogel encapsulating efferocytosis inhibitor MRX-2843 enabled a cascade regulation to orchestrate polarization, efferocytosis, and phagocytosis of peritoneal macrophages for realizing robust phagocytosis of tumor cells and powerful antigen presentation, offering a potent approach for ovarian cancer therapy via bridging the innate effector function of macrophages with their adaptive immune response. Moreover, our hydrogel is also applicable for potent treatment of inherent CD24-overexpressed triple-negative breast cancer, providing an emerging therapeutic regimen for the most lethal malignancies in women.

Pressurized intraperitoneal aerosol chemotherapy, reasons for interrupting treatment: a systematic review of the literature.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) gives encouraging results in the treatment of peritoneal metastasis (PM). The current recommendations require at least 3 sessions of PIPAC. However, some patients do not complete the full treatment course and stop after only 1 or 2 procedures, hence the limited benefit. A literature review was performed, with search terms including "PIPAC" and "pressurised intraperitoneal aerosol chemotherapy." Only articles describing the causes for premature termination of the PIPAC treatment were analysed. The systematic search identified 26 published clinical articles related to PIPAC and reporting causes for stopping PIPAC. The series range from 11 to 144 patients, with a total of 1352 patients treated with PIPAC for various tumours. A total of 3088 PIPAC treatments were performed. The median number of PIPAC treatments per patient was 2.1, the median PCI score at the time of the first PIPAC was 19 and the number of patients who did not complete the recommended 3 sessions of PIPAC was 714 (52.8%). Disease progression was the main reason for early termination of the PIPAC treatment (49.1%). The other causes were death, patients' wishes, adverse events, conversion to curative cytoreductive surgery and other medical reasons (embolism, pulmonary infection, etc…). Further investigations are necessary to better understand the causes for interrupting PIPAC treatment and also improving the selection of patients who are most likely to benefit from PIPAC.

Abstract 812: Treatment of metastatic cancers using immunotherapeutic cowpea mosaic virus nanoparticles

Abstract This study investigates the use of an immunotherapeutic plant virus, namely the cowpea mosaic virus (CPMV), that when used prophylactically and therapeutically can protect against metastatic cancer in multiple tumor mouse models. Metastatic cancer continues to be the main cause of death of most cancer patients, and new treatment modalities must be engineered to protect patients from metastatic disease. For instance, peritoneal metastases (PMs) are oftentimes fatal, and patients survive for a median 6 months following diagnosis. PMs are common for colon, ovarian, gastric, appendiceal, and pancreatic cancers. Previously, it was demonstrated that CPMV is a potent in situ vaccine causing tumor shrinkage with abscopal effect and long-term protection observed in tumor mouse models and canine cancer patients. CPMV functions as a toll like receptor (TLR) agonist and acts on innate immune cells to induce tumor cell killing and antigen processing to eventually prime adaptative and tumor-specific immunity. However, metastatic cancers such as PMs are not easily and directly injectable and therefore, we have expanded the ability of CPMV to protect against PMs by engineering targeted CPMV nanoparticles. Data indicates that CPMV can improve survival and slow tumor growth in a murine colon PM model compared to controls and that long-term survivors are further protected from re-challenge indicating tumor specificity. Analysis from current and past studies indicate that CPMV injection into the intraperitoneal space leads to distinct upregulation of immunostimulatory cytokines and recruitment of innate immune cell populations. PMs lead to extreme declines in quality of life of patients, and current treatments can be ineffective in slowing down or reducing tumor development and death - in tackling this problem, the data clearly points to the strong potential for CPMV-mediated therapeutics in the treatment and prophylaxis of PMs. Dr. Steinmetz is a co-founder of and has a financial interest in Mosaic ImmunoEngineering Inc. The other authors have no conflict of interest to declare. Acknowledgments: This work is supported in part through NIH grants R01 CA274640, R01 CA224605, R01 CA253615, CDMRP W81XWH2010742, and the Shaughnessy Family Fund for Nano-ImmunoEngineering (nanoIE at UC San Diego). Citation Format: Young Hun Chung, Britney A. Volckaert, Nicole F. Steinmetz. Treatment of metastatic cancers using immunotherapeutic cowpea mosaic virus nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 812.

Gastric Cancer with Peritoneal Metastases: Current Status and Prospects for Treatment

Gastric cancer (GC) has a poor prognostic and only one in four patients will have survived by 5 years after diagnosis. These poor results are due to the fact that most patients are diagnosed in advanced stages; peritoneal metastases (PM) are especially frequent and are difficult to treat. Currently, PM are considered a terminal stage of GC with a poor survival rate and are treated with palliative systemic chemotherapy. Since the beginning of the century, the treatment of PM from different origins has evolved; cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have become the treatment of choice for many malignant diseases that affect the peritoneum. CRS and HIPEC have also been used for patients with GC and PM, achieving survival results that have never been achieved when using systemic chemotherapy alone. The use of HIPEC can even prevent the development of peritoneal recurrences in patients with locally advanced GC as adjuvant therapy, can reduce the volume of peritoneal disease as neoadjuvant therapy, and can control symptoms in a palliative setting. The aim of this review is to collate the current scientific evidence regarding the treatment of PM of GC origin with surgery and intraperitoneal chemotherapy.

Survival and complications of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy in patients with intra-abdominal malignancies: A meta-analysis of randomized controlled trials.

Background: Peritoneal metastasis (PM) is an advanced stage of intra-abdominal malignancy with a very poor prognosis. In recent years, hyperthermic intraperitoneal chemotherapy (HIPEC) combined with cytoreductive surgery (CRS) has been utilized as an active treatment in the prevention and treatment of PM, with encouraging results. However, compared with CRS alone, the results of the CRS plus HIPEC strategy in the treatment of patients with intra-abdominal malignancies are still controversial. This study sought to determine the impact of HIPEC + CRS on patient survival and adverse events (AEs) by reviewing randomized controlled trials (RCTs) for all types of intra-abdominal malignancies. Methods: A PubMed, Embase, Cochrane Library, Web of Science and Clinical Trials.gov search extracted all RCTs until 12 October 2022, examining the CRS + HIPEC vs. CRS alone strategies in the treatment of various types of intra-abdominal malignancies. The outcomes included overall survival (OS), disease-free survival (DFS), relapse-free survival (RFS), progression-free survival (PFS) and AEs. The dichotomous data were pooled and reported as odds ratios (ORs) with 95% confidence intervals (CIs). The survival outcome data were pooled using hazard ratios (HRs) and corresponding 95% CIs. The Cochrane Collaboration's Risk of Bias Tool was used to assess the risk of bias in the included studies. Results: A total of 12 RCTs were included in this meta-analysis, including 873 patients in the CRS + HIPEC group and 878 patients in the CRS alone group. The studies included 3 (617 patients) on colorectal cancer, 4 (416 patients) on gastric cancer, and 5 (718 patients) on ovarian cancer. Our analysis showed no difference in OS between the CRS + HIPEC and CRS alone groups (HR: 0.79, 95% CI 0.62-1.01). Subgroup analysis showed that CRS + HIPEC improved the OS of gastric cancer patients (HR: 0.49, 95% CI 0.32-0.76) compared with CRS alone. However, CRS + HIPEC did not significantly improve the OS of colorectal cancer (HR: 1.06, 95% CI 0.81-1.38) and ovarian cancer (HR: 0.82, 95% CI 0.62-1.07) patients. In addition, there was no significant difference in DFS/RFS (HR: 0.78, 95% CI 0.57-1.07) or PFS (HR: 1.03, 95% CI 0.77-1.38) between the two groups. Compared with CRS alone, CRS with HIPEC had greater nephrotoxicity (OR: 0.45, 95% CI 0.21-0.98), while other AEs did not differ significantly between the two groups. Conclusion: Our results suggest that CRS + HIPEC may improve OS in gastric cancer patients compared with CRS alone, but we did not observe a benefit for DFS/RFS. For patients with ovarian and colorectal cancers, our results suggest that HIPEC + CRS does not appear to improve survival outcomes. In addition, CRS + HIPEC has higher nephrotoxicity than CRS alone. More evidence from RCTs is needed to evaluate whether the use of CRS + HIPEC is an appropriate option.

China Anti-Cancer Association (CACA) guidelines for holistic integrative management of cancer-peritoneal tumours from gastrointestinal tract

Peritoneal tumours have a large population and a poor prognosis with limited therapeutic options available, and are common originated from gastric, colorectal, appendix and other cancers. Traditionally, peritoneal tumours have long been considered to be a terminal condition with a median survival of 3-6 months, and the palliative symptomatic treatment is recommended. Recently, the multimodal therapeutic strategy of cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has resulted in more effective on the prevention and treatment of peritoneal metastasis, which can significantly improve the survival and quality of life. Under the guidance of the China Anti-Cancer Association (CACA), the "CACA Guidelines for Holistic Integrative Management of Cancer-Peritoneal Tumours" was jointly completed by experts in related fields organized by the Chinese Society of Peritoneal Oncology. This guideline is guided by the concept of integrative medicine and focuses on the domestic epidemiology, genetic background and original studies. It emphasizes the multidisciplinary team to holistic integrative medicine (MDT to HIM), and pays attention to the whole-course management of "prevention, screening, diagnosis, treatment, and rehabilitation". This guideline mainly focuses on peritoneal metastasis from gastrointestinal tumours, aiming to standardize the clinical diagnosis and treatment process, and jointly promote the management of peritoneal metastasis in China.

Response Evaluation in Patients with Peritoneal Metastasis Treated with Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC).

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) directed therapy emerged as a treatment of peritoneal metastasis (PM) a decade ago. The response assessment of PIPAC is not uniform. This narrative review describes non-invasive and invasive methods for response evaluation of PIPAC and summarizes their current status. PubMed and clinicaltrials.gov were searched for eligible publications, and data were reported on an intention-to-treat basis. The peritoneal regression grading score (PRGS) showed a response in 18-58% of patients after two PIPACs. Five studies showed a cytological response in ascites or peritoneal lavage fluid in 6-15% of the patients. The proportion of patients with malignant cytology decreased between the first and third PIPAC. A computed tomography showed stable or regressive disease following PIPAC in 15-78% of patients. The peritoneal cancer index was mainly used as a demographic variable, but prospective studies reported a response to treatment in 57-72% of patients. The role of serum biomarkers of cancer or inflammation in the selection of candidates for and responders to PIPAC is not fully evaluated. In conclusion, response evaluation after PIPAC in patients with PM remains difficult, but PRGS seems to be the most promising response evaluation modality.

Intraperitoneal administration of cabazitaxel-loaded nanoparticles in peritoneal metastasis models

Colorectal and ovarian cancers frequently develop peritoneal metastases with few treatment options. Intraperitoneal chemotherapy has shown promising therapeutic effects, but is limited by rapid drug clearance and systemic toxicity. We therefore encapsulated the cabazitaxel taxane in poly(alkyl cyanoacrylate) (PACA) nanoparticles (NPs), designed to improve intraperitoneal delivery. Toxicity of free and encapsulated cabazitaxel was investigated in rats by monitoring clinical signs, organ weight and blood hematological and biochemical parameters. Pharmacokinetics, biodistribution and treatment response were evaluated in mice. Biodistribution was investigated by measuring both cabazitaxel and the 2-ethylbutanol NP degradation product. Drug encapsulation was shown to increase intraperitoneal drug retention, leading to prolonged intraperitoneal drug residence time and higher drug concentrations in peritoneal tumors. As a result, encapsulation of cabazitaxel improved the treatment response in two in vivo models bearing intraperitoneal tumors. Together, these observations indicate a strong therapeutic potential of NP-based cabazitaxel encapsulation as a novel treatment for peritoneal metastases.

Cytoreductive Surgery (CRS) and HIPEC for Advanced Ovarian Cancer with Peritoneal Metastases: Italian PSM Oncoteam Evidence and Study Purposes

Ovarian cancer is the eighth most common neoplasm in women with a high mortality rate mainly due to a marked propensity for peritoneal spread directly at diagnosis, as well as tumor recurrence after radical surgical treatment. Treatments for peritoneal metastases have to be designed from a patient's perspective and focus on meaningful measures of benefit. Hyperthermic intraperitoneal chemotherapy (HIPEC), a strategy combining maximal cytoreductive surgery with regional chemotherapy, has been proposed to treat advanced ovarian cancer. Preliminary results to date have shown promising results, with improved survival outcomes and tumor regression. As knowledge about the disease process increases, practice guidelines will continue to evolve. In this review, we have reported a broad overview of advanced ovarian cancer management, and an update of the current evidence. The future perspectives of the Italian Society of Surgical Oncology (SICO) are discussed conclusively.

Decellularized extracellular matrix as scaffold for cancer organoid cultures of colorectal peritoneal metastases.

Peritoneal metastases (PM) from colorectal cancer (CRC) are associated with poor survival. The extracellular matrix (ECM) plays a fundamental role in modulating the homing of CRC metastases to the peritoneum. The mechanisms underlying the interactions between metastatic cells and the ECM, however, remain poorly understood, and the number of in vitro models available for the study of the peritoneal metastatic process is limited. Here, we show that decellularized ECM of the peritoneal cavity allows the growth of organoids obtained from PM, favoring the development of three-dimensional (3D) nodules that maintain the characteristics of in vivo PM. Organoids preferentially grow on scaffolds obtained from neoplastic peritoneum, which are characterized by greater stiffness than normal scaffolds. A gene expression analysis of organoids grown on different substrates reflected faithfully the clinical and biological characteristics of the organoids. An impact of the ECM on the response to standard chemotherapy treatment for PM was also observed. The ex vivo 3D model, obtained by combining patient-derived decellularized ECM with organoids to mimic the metastatic niche, could be an innovative tool to develop new therapeutic strategies in a biologically relevant context to personalize treatments.