Treatment Of Peritoneal Metastases Research Articles

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.

Evaluating the concept of gas‑based intraperitoneal hyperthermia beyond 43˚C in the treatment of peritoneal metastasis: A pilot study.

While hyperthermic intraperitoneal applications have demonstrated high efficacy in treating peritoneal metastases (PM), these applications are limited to temperatures of 41-43˚C to prevent a harmful increase in core temperature. However, since gaseous substances display low specific heat capacities, gas-based hyperthermia could potentially increase surface temperatures without affecting the body's core temperature. To the best of our knowledge, the present study is the first to explore the in vivo feasibility of gas-based hyperthermia via spatial and time-based distribution. In the present study, a temperature-isolated, abdominal box model was created with fresh peritoneal tissue exposed to continuous high-volume airflow temperatures ranging between 47 and 69˚C. Heat conduction within the peritoneal tissues was measured using temperature microsensors. Temperature build-up at different time points during the procedure was calculated and the safest option to perform gas-based intraperitoneal hyperthermia beyond 43˚C was identified using an in vivo swine model. In subsequent experiments, viability and cytotoxicity of HT-29 colon cancer cells were measured following short-term hyperthermia. The present study demonstrated that the application of gas-based intraperitoneal hyperthermia with temperatures up to 50˚C is possible without increasing the core temperature to harmful levels. Gas-based intraperitoneal hyperthermia can induce a histological reaction on the peritoneal surface, and it can also result in decreased viability and increased cytotoxicity of HT-29 cells. The concept of extreme hyperthermia may be of great clinical importance as it could significantly increase local cytotoxicity in PM without increasing the body's core temperature. Further studies are required to investigate the benefits, as well as the restrictions, of this novel concept.

Safety, feasibility, and application of intraperitoneal gas-based hyperthermia beyond 43°C in the treatment of peritoneal metastasis: An in-vivo pilot study.

Background43°Celsius (C) is currently the highest temperature used in the treatment of peritoneal metastasis (PM). Despite sufficient data on water- based hyperthermic solutions in PM treatment, there is currently no information on gas-based hyperthermia extending beyond 43°C. This study is the first to provide in-vivo data on different organ systems during and after intraperitoneal gas-based hyperthermia beyond 43°C. The aim of this study is to explore in-vivo feasibility, safety, and efficacy of this novel concept from a biological perspective.MethodsFor this study, three swine were subjected to laparoscopy and subsequent gas-based intraperitoneal hyperthermia at 48°, 49° and 50°C under a high-flow air stream. Intraoperative data from multiple temperature sensors were analysed. Additionally, intraoperative anaesthesiologic and gasometrical data was analysed. Postoperatively, swine were monitored for one week and laboratory work-up was performed on postoperative days 1, 3 and 7.ResultsDuring gas-based intraperitoneal hyperthermia, anesthesiologic parameters did not exhibit critical values. No intra- or postoperative complications were observed. Distinct temperature measurements on the skin, cystohepatic triangle and esophagus did not display any temperature increase. Postoperative laboratory workup did not show any changes in hemoglobin, white blood cell count, platelets, or kidney function.DiscussionBased on our data, there are no safety concerns for the application of gas-based hyperthermia between 48 - 50°C. In fact, no critical systemic temperature increase was observed. With respect to possible limitations, further in-vivo studies are required to evaluate whether gas-based intraperitoneal hyperthermia may be a therapeutic option for PM patients.

Soluble factors in malignant ascites promote the metastatic adhesion of gastric adenocarcinoma cells.

Adenocarcinoma of the proximal stomach is the fastest rising malignancy in North America. It is commonly associated with peritoneal accumulation of malignant ascites (MA), a fluid containing cancer and inflammatory cells and soluble proteins. Peritoneal metastasis (PM) is the most common site of gastric cancer (GC) progression after curative-intent surgery and is the leading cause of death among GC patients. Using a panel of gastric adenocarcinoma cell lines (human: MKN 45, SNU-5; murine: NCC-S1M), we demonstrate that prior incubation of GC cells with MA results in a significant (> 1.7-fold) increase in the number of cells capable of adhering to human peritoneal mesothelial cells (HPMC) (p < 0.05). We then corroborate these findings using an ex vivo PM model and show that MA also significantly enhances the ability of GC cells to adhere to strips of human peritoneum (p < 0.05). Using a multiplex ELISA, we identify MIF and VEGF as consistently elevated across MA samples from GC patients (p < 0.05). We demonstrate that agents that block the effects of MIF or VEGF abrogate the ability of MA to stimulate the adhesion of GC cells to adhere to human peritoneum and promote both ex vivo and in vivo metastases. Agents targeting MIF or VEGF may be relevant to the treatment or prevention of PM in GC patients.

Impact of cumulative complications on 1-year treatment-related healthcare costs in patients with colorectal peritoneal metastases undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy.

BackgroundThe aim of this study was to evaluate the impact of all minor and major complications on treatment-related healthcare costs in patients who undergo cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for the treatment of colorectal peritoneal metastases (PMs).MethodPatients with histologically proven colorectal PMs who underwent CRS + HIPEC from March 2006 to October 2019 in a tertiary referral centre were retrospectively identified from a prospectively maintained database. Patients were divided into six subgroups according to the severity of the complications, which were scored using the comprehensive complication index (CCI) (CCI 0–9.9, CCI 10–19.9, CCI 20–29.9, CCI 30–39.9, CCI 40–49.9, and CCI 50 or higher). Treatment-related healthcare costs up to 1 year after CRS + HIPEC were obtained from the financial department. Differences in costs and survival outcomes were compared using the chi-squared test and Kruskal–Wallis H test.ResultsA total of 142 patients were included (CCI 0–9.9, 53 patients; CCI 10–19.9, 0 patients; CCI 20–29.9, 45 patients; CCI 30–39.9, 14 patients; CCI 40–49, 9 patients; and CCI 50 or higher, 21 patients). Median (interquartile range) treatment-related healthcare costs increased significantly and exponentially for the CCI 30–39, CCI 40–49, and CCI 50 or higher groups (€48 993 (€44 262–€84 805); €57 167 (€43 047–€67 591); and €82 219 (€55 487–€145 314) respectively) compared with those for the CCI 0–9.9 and CCI 20–29.9 groups (€33 856 (€24 433–€40 779) and €40 621 (€31 501–€58 761) respectively, P < 0.010).ConclusionTreatment-related healthcare costs increase exponentially as more complications develop among patients who undergo CRS + HIPEC for the treatment of colorectal PMs. Anastomotic leakages after CRS + HIPEC lead to an increase of 295 per cent of treatment-related healthcare costs.

Thymosin alpha 1 as an adjuvant to hyperthermic intraperitoneal chemotherapy in an experimental model of peritoneal metastases from colonic carcinoma

IntroductionHeated intraperitoneal chemotherapy (HIPEC) is currently implemented in the treatment of peritoneal metastases from colorectal carcinoma (PM-CRC) origin. However, recurrence is common and the effectiveness of HIPEC has been questioned. The aim of this study was to evaluate the use of thymosin alpha 1 (Tα1), an immunomodulatory molecule, as an adjuvant to HIPEC treatment. MethodsWe developed an experimental model of HIPEC by the induction of PM-CRC in C57BL mice and intra-abdominal perfusion of mitomycin C (MMC). Mice were treated with Tα1 at 0.6 mg/kg for 5 days after HIPEC. Clinical and immunological parameters were compared between HIPEC and HIPEC + Tα1 groups. ResultsTreatment with Tα1 increased overall survival of mice compared to HIPEC treatment alone and sham-treated animals (16.1 ± 0.8 vs. 14.1 ± 0.6 and 11.8 ± 0.8, respectively, p = 0.02). Tα1 had no direct anti-tumor effect, as seen by lack of inhibition of tumor cell proliferation. Tα1 treatment induced a T helper (Th) 1 immune response in tumor metastases as evidenced by a significant increase of the Th1-specific markers IFN-γ and T-bet (1.21 ± 0.3 vs. 0.52 ± 0.08, p < 0.05; 0.88 ± 0.04 vs. 0.64 ± 0.14, p < 0.05, respectively). This Th1 skew was accompanied by increased CD8+ infiltration into omental and visceral metastases by Tα1 treatment compared to sham and HIPEC-treated animals (21.24 ± 2.16 vs. 10.45 ± 0.89 and 7.7 ± 1.3, p < 0.001; 14.12 ± 1.54 vs. 12.12 ± 0.01 and 6.64 ± 0.87, p < 0.01, respectively). ConclusionsTα1 augments the effect of HIPEC by the induction of a Th1 anti-tumor immune response. Further experiments should evaluate Tα1 and other novel immunomodulators in order to exploit the immunological opportunities created by HIPEC.

Abstract 272: Effective treatment of colorectal peritoneal metastases by exploiting a molecular subtype specific vulnerability

Abstract In colorectal cancer, peritoneal metastases (PMs) associate with severe morbidity and dismal prognosis. Given the incidence of this disease and the lack of adequate treatments currently available, PMs pose a large unmet clinical need. Although PMs can be accompanied by more widespread metastatic disease, it often occurs as the only sign of dissemination. This implies that the route of metastatic spread to the peritoneum differs from that to distant organs. PMs are thought to result from cancer cells that spill into the abdominal cavity, and are able to attach to the peritoneal lining and form tumor deposits. This cascade places specific demands on the cancer cells. Here, we report that colorectal cancers that present with PMs almost universally classify as consensus molecular subtype 4 (CMS4). This previously recognized disease entity is characterized by mesenchymal features, poor prognosis, and resistance to therapies currently used against peritoneal metastases, which explains their limited efficacy. By leveraging disease models that capture CMS4-specific features, including the ability to form PMs in vivo, we identified elesclomol as a highly effective agent. Elesclomol kills cancer cells in a copper-dependent fashion by targeting the oxidative phosphorylation machinery, which we found to be a specific vulnerability of CMS4 cancers. Elesclomol-Cu2+ was effective following only minutes of exposure to CMS4 cell lines and organoids, supporting its use in intra-abdominal treatment procedures. It is therefore a promising candidate for the local treatment of peritoneal metastases of colorectal cancer. Citation Format: Sanne Bootsma, Mark P. Dings, Leandro Ferreira Moreno, Kristiaan J. Lenos, Louis Vermeulen, Maarten F. Bijlsma. Effective treatment of colorectal peritoneal metastases by exploiting a molecular subtype specific vulnerability [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 272.

Abstract 6284: Exosomal miR-29b derived from mesenchymal stem cell (MSC) may suppress peritoneal metastasis via the effects on peritoneal mesothelial cells

Abstract Background: Mesothelial cells play tumor-promoting roles in the development of peritoneal metastasis (PM) through mesothelial-mesenchymal transition (MMT). We reported miR-29b suppressed MMT of human peritoneal mesothelial cell (HPMC). Methods: MiR-29b mimics and negative control miRNA (NC) were transfected to human bone marrow derived MSC by lipofection method. Exosomes were purified from the culture supernatants of the MSC with ultracentrifugation, and added to HPMC. Proliferation and migration of HPMC were examined with MTT assay and transwell assay, respectively. MMT of HPMC induced by 10 ng/ml TGF-β, and evaluated with immunofluorescence staining. Results: MSC transfected with miR-29b mimics produced significantly increased amounts of miR-29b-containing exosomes (p&amp;lt;0.0001, n=3) as compared with negative control. After 24h-culture with PKH-26 stained exosomes, HPMC actively took the exosomes. After 48 hr-culture with TGF-β, HPMC apparently changed the morphology from round to spindle shape. The expression level of E-cadherin and Calretinin in HPMC was decreased while vimentin and Fibronectin tended to be upregulated by TGF-β. However, exosomes from miR-29b transfected MSC significantly suppressed the morphological changes and reduced the expression levels of vimentin and Fibronectin with restored expression of E-cadherin and Calretinin, suggesting the inhibition of MMT in HPMC. The exosome inhibited the proliferation and migration of HPMC by 31±14% (p&amp;lt;0.01, n=5) and 67±9% (p&amp;lt;0.01, n=3), and inhibited the adhesion of NUGC by 90±3% (p&amp;lt;0.001, n=5) as compared with NC exosome. Conclusion: Exosomes from MSC transfected with miR-29b mimic efficiently suppresses MMT. Replacement of the miR-29b in peritoneal cavity might be used for the treatment of PM partially via the effects on mesothelial cell. Citation Format: Yuki Kimura, Hideyuki Ohzawa, Yuki Kaneko, Kohei Tamura, Yurie Futoh, Kazuya Takahashi, Akira Saito, Mineyuki Tojo, Hideyo Miyato, Joji Kitayama. Exosomal miR-29b derived from mesenchymal stem cell (MSC) may suppress peritoneal metastasis via the effects on peritoneal mesothelial cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6284.

Molecular Mechanisms and Potential Rationale of Immunotherapy in Peritoneal Metastasis of Advanced Gastric Cancer.

Peritoneal metastasis (PM) is one of the most frequent metastasis patterns of gastric cancer (GC), and the prognosis of patients with PM is very dismal. According to Paget’s theory, disseminated free cancer cells are seeded and survive in the abdominal cavity, adhere to the peritoneum, invade the subperitoneal tissue, and proliferate through angiogenesis. In these sequential processes, several key molecules are involved. From a therapeutic point of view, immunotherapy with chemotherapy combination has become the standard of care for advanced GC. Several clinical trials of newer immunotherapy agents are ongoing. Understanding of the molecular process of PM and the potential rationale of immunotherapy for PM treatment is necessary. Beyond understanding of the molecular aspect of PM, many studies have been conducted on the modality of treatment of PM. Notably, intraperitoneal approaches, including chemotherapy or immunotherapy, have been conducted, because systemic treatment of PM has limitations. In this study, we reviewed the molecular mechanisms and immunologic aspects of PM, and intraperitoneal approaches under investigation for treating PM.

Assessment of postoperative pain after pressurized intraperitoneal aerosol chemotherapy (PIPAC) in the treatment of peritoneal metastasis.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new surgical technique, for the treatment of initially unresectable peritoneal metastasis (PM). Our objective was to assess postoperative pain and morbidity. Between July 2016 and September 2020, data from 100 consecutive PIPAC procedures with oxaliplatin (PIPAC Ox) or doxorubicin-cisplatin (PIPAC C/D) in 49 patients with PM (all etiologies) were analyzed. Pain was self-assessed using a visual analog scale (VAS) of 0-10. The median PIPAC procedures per patient were 2 [1-3]. Patients indicated greatest pain at 4pm on the day of the procedure (D0) and on postoperative D1 at 8 am and 4pm. Postprocedural moderate-to-severe pain (VAS 4-10) was more frequent with PIPAC Ox than with PIPAC C/D, respectively 14 (36.8%) vs 7 (13.5%); p = 0.010. Hospitalization was longer for patients with moderate-to-severe pain than for others (median 4days [3-7] vs 3days [2-4], p = 0.004). Multivariate analysis identified oxaliplatin as a factor associated with greater pain (OR [95% CI], 2.95 [1.10-7.89]. Opiate administration was similar after PIPAC Ox and PIPAC C/D procedures, p = 0.477. PIPAC was well-tolerated, and pain was well-controlled in the majority of patients. Pain was greatest at 4pm on D0 and 8 am and 4pm on D1. PIPAC Ox is associated with greater pain than PIPAC C/D, independently of opiate treatment. Moderate-to-severe pain was associated with longer hospital stays.

Update of randomized controlled trials evaluating cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in prevention and therapy of peritoneal metastasis: a systematic review.

BackgroundCytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is associated with favorable short- and long-term oncological outcomes in highly selected patients with peritoneal metastasis (PM). The aim of our review was to review published, recruiting or ongoing randomized controlled trials (RCTs) evaluating CRS and HIPEC vs. other strategies (systemic chemotherapy or CRS alone) and to update the studies recently described in 2016.ContentSystematic review according to PRISMA guidelines. Searches for published and ongoing trials were based, respectively, on PubMed and international clinical databases since 2016.Summary46 trials randomized 9,063 patients: 13 in colorectal cancer (3 in therapeutic strategy and 10 in prophylactic strategy), 16 in gastric cancer (4 in therapeutic strategy and 12 in prophylactic strategy) and 17 in ovarian cancer (12 in front-line therapy and 5 in recurrence settings).OutlookIn contrast to many recruiting studies, few published studies analyzed the potential advantage of CRS and HIPEC in therapeutic and prophylactic treatment of PM. The potential effect of this combined treatment has been proven in ovarian cancer in interval surgery, but remains still debated in other situations. Promising trials are currently recruiting to provide further evidence of the effectiveness of CRS and HIPEC.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) for unresectable PM from gastric cancer outstanding result from multicenter cohort study.

331 Background: PIPAC is a recent approach for intraperitoneal chemotherapy with promising results for patients with peritoneal metastasis (PM). It is a safe and well-tolerated treatment. Our aim was to report oncological outcomes after PIPAC for gastric PM. Methods: International retrospective cohort study of consecutive patients with gastric PM. Outcome measures were overall survival (OS), radiological response (RECIST), histological response by use of Peritoneal regression grading system (PRGS) and cytology, peritoneal cancer index (PCI) and symptoms. Results: 586 non-selected patients with a median age of 56 (47-64) years, 54% of them were female and underwent a total of 1566 PIPAC procedures. 37% of patients were treated with 2 or more lines of IV chemotherapy, median PCI at first PIPAC was 14 (7-24) and 63% of them were with signet ring adenocarcinoma. Grade III-IV morbidity was 5.1 % and 1.9% died within 30 days from PIPAC procedure. Median OS was 15.4 months from diagnosis and 20.1 months for patient with more than 3 PIPAC. 263/586 patients (44.9%) had ≥3 procedures ( pp: per protocol) with the following outcomes: RECIST: 4.3% complete response 11% partial remission, 44% stable; PRGS1 39% at PIPAC3 and negative cytology at PIPAC3 in 16% of patient. In multivariate analysis, 3 PIPAC or more HR 0.3 (95% CI 0.27-0.51), 2nd and 3rd line of chemotherapy HR 0.48 (95% CI 0.25-0.92) and CRS&amp;HIPEC after PIPAC HR 0.3 (95% CI 0.18-0.51) were predictors for survival. Conclusions: Based on this large multicentre cohort study, PIPAC could be considered as an option for the treatment of PM from gastric cancer. More prospective study will validate this indication in the near future.

Safety and efficacy of pressurized intraperitoneal aerosolized chemotherapy in appendiceal and colorectal cancer patients with peritoneal carcinomatosis: A first-in-US phase I study.

125 Background: Pressurized intraperitoneal aerosolized chemotherapy (PIPAC) is being evaluated as a novel minimally invasive palliative treatment of peritoneal metastases (PM). Prior studies have established the feasibility and safety of repeated PIPAC treatments in gastrointestinal and gynecologic cancers. The goal of the present phase 1 trial was to establish the safety and feasibility of PIPAC oxaliplatin in a highly chemotherapy refractory colorectal and appendiceal cancer patient population. Methods: Patients with biopsy-proven peritoneal metastases from colorectal or appendiceal cancer underwent up to three PIPAC treatments using oxaliplatin (92 mg/m2) with a six-week interval at two academic centers. Patients with bowel obstruction, extra-peritoneal metastases, or poor performance status (ECOG&gt;2) were excluded. PIPAC was nebulized over 5 min with a 30 min aerosol dwell time. Apart from the first PIPAC cycle, the patients also received a sensitizing dose of 5FU/LV (400mg/m2) within 24 hours of the procedure. Primary end point was safety as assessed by dose limiting toxicities within 6 weeks of the first PIPAC. Secondary endpoints included safety with the addition of 5FU/LV, efficacy, surgical morbidity, technical failure rate, progression-free and overall survival, pharmacokinetics (PK), and quality of life assessment. Results: A total of 8 patients were included: 5 colorectal; and 3 appendiceal. Median number of prior chemotherapy cycles was 2 (Interquartile range – IQR; 1.5-3.5). All patients were refractory to systemic oxaliplatin-based chemotherapy. Median time from diagnosis to PIPAC was 16 months (IQR; 5.6, 17.5) and Peritoneal Carcinomatosis Index was 29 (IQR; 20.5, 31.5). Five (62.5%) patients completed 3 PIPAC cycles while in 3 (37.5%) patients PIPAC was discontinued due to disease progression within the peritoneal cavity. No surgical complication or dose limiting toxicity was observed. Only one patient developed grade 3 treatment-related toxicity after first PIPAC (anemia), and another patient after second PIPAC (abdominal pain and anemia). At the completion of PIPAC treatment 5 patients had stable disease and 3 had disease progression. Pharmacokinetic, histologic response and preliminary survival data will be presented at the meeting. Conclusions: PIPAC with oxaliplatin is safe and feasible in a highly chemotherapy refractory cohort of appendiceal and colorectal carcinomatosis patients with or without sensitizing 5-FU/ LV. Clinical trial information: NCT04329494.

Application and prospect of cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy in the treatment of peritoneal metastasis from colorectal cancer

Colorectal cancer is one of the common malignant tumors in China, and its incidence is increasing with years. As the second most common metastatic site of colorectal cancer, peritoneum is difficult to diagnose early and with a poor prognosis. Systemic intravenous chemotherapy was used as the main treatment strategy for peritoneal metastasis in the past, but its systemic toxic and side effects were obvious, and it could not effectively control tumor progression. In recent years, the continuous development of surgical techniques, concepts, and equipment, as well as the introduction of new chemotherapy drugs and targeted drugs have significantly improved the quality of life and prognosis of patients with peritoneal metastasis of colorectal cancer. Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) can effectively eradicated the intraperitoneal free cancer cells and subclinical lesions, while reducing systemic side effects of chemotherapy drugs, and achieve the radical cure of the tumor at the macro and micro levels to the greatest extent. It has been used as the first-line treatment program for peritoneal metastasis of colorectal cancer at home and abroad. This article focuses on the analysis and summary of the survival efficacy, prognostic factor analysis, and chemotherapy safety of CRS+ HIPEC in the treatment of colorectal cancer peritoneal metastasis. The existing problems and controversies of HIPEC therapy are discussed simultaneously.

Crosstalk between cancer-associated fibroblasts and immune cells in peritoneal metastasis: inhibition in the migration of M2 macrophages and mast cells by Tranilast

BackgroundThe role of tumor–stroma interactions in tumor immune microenvironment (TME) is attracting attention. We have previously reported that cancer-associated fibroblasts (CAFs) contribute to the progression of peritoneal metastasis (PM) in gastric cancer (GC), and M2 macrophages and mast cells also contribute to TME of PM. To elucidate the role of CAFs in TME, we established an immunocompetent mouse PM model with fibrosis, which reflects clinical features of TME. However, the involvement of CAFs in the immunosuppressive microenvironment remains unclear. In this study, we investigated the efficacy of Tranilast at modifying this immune tolerance by suppressing CAFs.MethodsThe interaction between mouse myofibroblast cell line LmcMF and mouse GC cell line YTN16 on M2 macrophage migration was investigated, and the inhibitory effect of Tranilast was examined in vitro. Using C57BL/6J mouse PM model established using YTN16 with co-inoculation of LmcMF, TME of resected PM treated with or without Tranilast was analyzed by immunohistochemistry.ResultsThe addition of YTN16 cell-conditioned medium to LmcMF cells enhanced CXCL12 expression and stimulated M2 macrophage migration, whereas Tranilast inhibited the migration ability of M2 macrophages by suppressing CXCL12 secretion from LmcMF. In PM model, Tranilast inhibited tumor growth and fibrosis, M2 macrophage, and mast cell infiltration and significantly promoted CD8 + lymphocyte infiltration into the tumor, leading to apoptosis of cancer cells by an immune response.ConclusionTranilast improved the immunosuppressive microenvironment by inhibiting CAF function in a mouse PM model. Tranilast is thus a promising candidate for the treatment of PM.

Cytoreduction and hyperthermic intraperitoneal chemotherapy in the treatment of peritoneal metastases from colorectal cancer in the Czech Republic in 2018.

For highly selected patients with peritoneal metastases (PM) from colorectal cancer (CRC), an aggressive surgical approach with intraperitoneal chemotherapy may be beneficial. This management may prolong overall survival, which is well documented by the results of a number of clinical trials. In the Czech Republic, five specialized centers of surgical oncology are able to perform cytoreductive surgery (CRS) in combination with hyperthermic intraperitoneal chemotherapy (HIPEC). All of these centers provided accurate information on the number of CRS procedures in 2018 in the PM CRC indication. The estimation of the prevalence of peritoneal metastases from CRC is based on data from the Czech National Cancer Registry. To determine the number of cytoreductive procedures performed in patients with peritoneal metastases from CRC in the Czech Republic in 2018, and to compare it with the number of patients who could hypothetically benefit from this procedure according to statistical data. Twenty-five CRS/HIPEC procedures were performed on patients with peritoneal metastases from CRC in 2018 in the Czech Republic. However, based on the prevalence of peritoneal metastases from CRC in the Czech Republic, cytoreduction with intraperitoneal chemotherapy (CRS/HIPEC) could probably bring benefit to a minimum of 150 patients a year in the Czech Republic. In the Czech Republic in 2018, the cytoreduction and HIPEC procedures for peritoneal metastases from CRC were performed in significantly fewer cases than would correspond to the estimated number of potentially curable patients.To increase the awareness of this issue and improve the number of potentially curative cytoreductive procedures, there will be necessary better awareness and closer cooperation among specialized centers, general surgeons, and clinical oncologists.