Pressurised intraperitoneal aerosol chemotherapy: rationale, evidence, and potential indications

Pharmaceutical strategies in improving anti-tumour efficacy and safety of intraperitoneal therapy for peritoneal metastasis

Introduction: In selected patients with limited peritoneal metastasis (PM), favorable tumor biology, and a good clinical condition, there is an indication for combination of cytoreductive surgery (CRS) and subsequent intravenous (IV) or intraperitoneal (IP) chemotherapy. Compared with IV injection, IP therapy can achieve a high drug concentration within the peritoneal cavity with low systemic toxicity, however, the clinical application of IP chemotherapy is limited by the related abdominal pain, infection, and intolerance.Areas covered:To improve the anti-tumor efficacy and safety of IP therapy, various pharmaceutical strategies have been developed and show promising potential. This review discusses the specialized modification of traditional drug delivery systems and demonstrates the preparation of customized drug carriers for IP therapy, including chemotherapy and gene therapy. IP therapy has important clinical significance in the treatment of PM using novel anti-tumor agents as well as conventional drugs in new applications.Expert opinion: Although IP therapy exhibits good performance both in mouse models and in patients with PM in clinical trials, its clinical application remains limited due to the serious side effects and low acceptability. Further investigations, including pharmaceutical strategies, are needed to develop potential IP therapy, focusing on the efficacy and safety thereof.

10 ns PEFs induce a histological response linked to cell death and cytotoxic T-lymphocytes in an immunocompetent mouse model of peritoneal metastasis

PURPOSE

The application of nanosecond pulsed electric fields (nsPEFs) could be an effective therapeutic strategy for peritoneal metastasis (PM) from colorectal cancer (CRC). The aim of this study was to evaluate in vitro the sensitivity of CT-26 CRC cells to nsPEFs in combination with chemotherapeutic agents, and to observe the subsequent in vivo histologic response.

METHODS

In vitro cellular assays were performed to assess the effects of exposure to 1, 10, 100, 500 and 1000 10 ns pulses in a cuvette or bi-electrode system at 10 and 200 Hz. nsPEF treatment was applied alone or in combination with oxaliplatin and mitomycin. Cell death was detected by flow cytometry, and permeabilization and intracellular calcium levels by fluorescent confocal microscopy after treatment. A mouse model of PM was used to investigate the effects of in vivo exposure to pulses delivered using a bi-electrode system; morphological changes in mitochondria were assessed by electron microscopy. Fibrosis was measured by multiphoton microscopy, while the histological response (HR; hematoxylin-eosin-safran stain), proliferation (KI67, DAPI), and expression of immunological factors (CD3, CD4, CD8) were evaluated by classic histology.

RESULTS

10 ns PEFs exerted a dose-dependent effect on CT-26 cells in vitro and in vivo, by inducing cell death and altering mitochondrial morphology after plasma membrane permeabilization. In vivo results indicated a specific CD8+ T cell immune response, together with a strong HR according to the Peritoneal Regression Grading Score (PRGS).

CONCLUSIONS

The effects of nsPEFs on CT-26 were confirmed in a mouse model of CRC with PM.

A Phase I Dose Escalation Study of Oxaliplatin, Cisplatin and Doxorubicin Applied as PIPAC in Patients with Peritoneal Carcinomatosis

Simple Summary

This study is one of the very few phase I trials on intraperitoneal chemotherapy applied as PIPAC. Cisplatin and doxorubicin may be safely used as PIPAC at a dose of 30 mg/m² and 6 mg/m², respectively; oxaliplatin can be used at an intraperitoneal dose of 135 mg/m². No serious adverse event was reported. The dosages achieved to date are the highest ever used in PIPAC. The results of these investigations should be the starting point for further clinical phase II trials regarding repeated PIPAC, possibly associated with systemic chemotherapy.

Abstract

Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) is an innovative laparoscopic intraperitoneal chemotherapy approach with the advantage of a deeper tissue penetration. Thus far, oxaliplatin has been administered at an arbitrary dose of 92 mg/m², cisplatin at 7.5 mg/m² and doxorubicin 1.5 mg/m². This is a model-based approach phase I dose escalation study with the aim of identifying the maximum tolerable dose of the three different drugs. The starting dose of oxaliplatin was 100 mg/m²; cisplatin was used in association with doxorubicin: 15 mg/m² and 3 mg/m² were the respective starting doses. Safety was assessed according to Common Terminology Criteria for Adverse Events (CTCAE version 4.03). Thirteen patients were submitted to one PIPAC procedure. Seven patients were treated with cisplatin and doxorubicin and 6 patients with oxaliplatin; no dose limiting toxicities and major side effects were found. Common adverse events included postoperative abdominal pain and nausea. The maximum tolerable dose was not reached. The highest dose treated cohort (oxaliplatin 135 mg/m²; cisplatin 30 mg/m² and doxorubicin 6 mg/m²) tolerated PIPAC well. Serological analyses revealed no trace of doxorubicin at any dose level. Serum levels of cis- and oxaliplatin reached a peak at 60–120 min after PIPAC and were still measurable in the circulation 24 h after the procedure. Cisplatin and doxorubicin may be safely used as PIPAC at a dose of 30 mg/m² and 6 mg/m², respectively; oxaliplatin can be used at an intraperitoneal dose of 135 mg/m². The dosages achieved to date are the highest ever used in PIPAC.

Current practice and perceptions of safety protocols for the use of intraperitoneal chemotherapy in the operating room: results of the IP-OR international survey

OBJECTIVES

To assess the risk perception and the uptake of measures preventing environment-related risks in the operating room (OR) during hyperthermic intraperitoneal chemotherapy (HIPEC) and pressurized intraperitoneal aerosol chemotherapy (PIPAC).

METHODS

A multicentric, international survey among OR teams in high-volume HIPEC and PIPAC centers: Surgeons (Surg), Scrub nurses (ScrubN), Anesthesiologists (Anest), Anesthesiology nurses (AnesthN), and OR Cleaning staff (CleanS). Scores extended from 0-10 (maximum).

RESULTS

Ten centers in six countries participated in the study (response rate 100%). Two hundred and eleven responses from 68 Surg (32%), 49 ScrubN (23%), 45 Anest (21%), 31 AnesthN (15%), and 18 CleanS (9%) were gathered. Individual uptake of protection measures was 51.4%, similar among professions and between HIPEC and PIPAC. Perceived levels of protection were 7.57 vs. 7.17 for PIPAC and HIPEC, respectively (p<0.05), with Anesth scoring the lowest (6.81). Perceived contamination risk was 4.19 for HIPEC vs. 3.5 for PIPAC (p<0.01). Information level was lower for CleanS and Anesth for HIPEC and PIPAC procedures compared to all other responders (6.48 vs. 4.86, and 6.48 vs. 5.67, p<0.01). Willingness to obtain more information was 86%, the highest among CleanS (94%).

CONCLUSIONS

Experience with the current practice of safety protocols was similar during HIPEC and PIPAC. The individual uptake of protection measures was rather low. The safety perception was better for PIPAC, but the perceived level of protection remained relatively low. The willingness to obtain more information was high. Intensified, standardized training of all OR team members involved in HIPEC and PIPAC is meaningful.

Wogonoside promotes apoptosis and ER stress in human gastric cancer cells by regulating the IRE1α pathway

Gastric cancer is a disease that occurs in the digestive system of humans and remains a problem in the medical field. Wogonoside, a natural flavonoid, has been reported to exert antitumor effects on various types of tumors. However, the effects of wogonoside on gastric cancer remain elusive. The aim of the present study was to detect whether wogonoside treatment could induce apoptosis and ER stress in gastric cancer cells. In the present study, CCK-8 assay was used to detect the cell viability, Annexin V/PI staining was used to detect the cells apoptosis, western blot analysis and real-time PCR analysis was used to detect the endoplasmic reticulum (ER) stress in the AGS and MKN-45 gastric cancer cell lines. Wogonoside treatment reduced the viability of AGS and MKN-45 cells and induced apoptosis. Furthermore, the expression level of caspase-3 and -9 significantly increased following wogonoside treatment compared with that in non-treated cells, and the protein expression levels of proapoptotic Bax and antiapoptotic Bcl-2 increased and decreased, respectively compared with that in the control group. In addition, the phosphorylated protein expression levels of mitogen-activated protein kinase kinase 5 (ASK1) and JNK increased following wogonoside treatment, and the protein expression levels of tumor necrosis factor receptor-associated factor 2 (TRAF2) and serine/threonine-protein kinase/endoribonuclease IRE1 (IRE1α) were also increased following treatment with 50 µM wogonoside for 48 h. Furthermore, the interactions between IRE1α, TRAF2 and ASK1 significantly increased following wogonoside treatment, suggesting that wogonoside induced endoplasmic reticulum (ER) stress in the AGS and MKN-45 cell lines. In addition, small interfering RNA-mediated silencing of IRE1α suppressed the activity of the IRE1α-TRAF2-ASK1 complex and prevented wogonoside-induced cell apoptosis. In conclusion, the results of the present study suggested that wogonoside exhibited antitumor activity by inducing ER stress-associated cell death through the IRE1α-TRAF2-ASK1 pathway.

Local peritoneal toxicity from adjuvant pressurized intraperitoneal aerosol chemotherapy with oxaliplatin in high-risk patients with colonic cancer

This research letter describes unexpected and unacceptable local toxicity manifesting as abdominal pain after adjuvant pressurized intraperitoneal aerosol chemotherapy with 92 mg/m2 oxaliplatin in the PIPAC-OPC3 study. It is not clear whether the toxicity is dose- or drug-dependent (or both), but the preliminary data suggest that tolerability is improved by dose reduction to 46 mg/m2.

Experimental evaluation of icodextrin delivery as pressurized aerosol (PIPAC): Antiadhesive and cytotoxic effects

BACKGROUND

Icodextrin (IDX) is an antiadhesive polymer that can be used as a carrier solution for intraperitoneal (IP) delivery of chemotherapeutic drugs.

METHODS

We investigated the suitability of IDX solution as a carrier of Cisplatin and Doxorubicin for delivery as pressurized intraperitoneal aerosol chemotherapy (PIPAC). We examined the sprayability of IDX, the aerosol characteristics, the stability of the molecule after aerosolization, the effects of IDX on the adhesion of MKN45 human gastric cancer cells, the synergistic effect of aerosolized IDX with Cisplatin and Doxorubicin, and the chemical stability of IDX, Cisplatin, and Doxorubicin in combination.

RESULTS

Delivery of IDX as PIPAC is feasible with no particular restrictions. The median droplet size of 35.7 μm did not change at increasing concentrations. IDX withstood the shear forces applied by the nebulizer and remained stable after aerosolization (ANOVA, p = 0.97). IDX did not impair the cytotoxic effects of Cisplatin and Doxorubicin (ns). IDX had a significant antiadhesive impact alone (p < 0.03) and in combination with Cisplatin and Doxorubicin (p < 0.02). IDX as a carrier for Cisplatin and Doxorubicin remained stable at 4 °C for three months and did not cause degradation of those two substances.

CONCLUSION

The proposed combination takes advantage of the antiadhesive properties of IDX, the cytotoxic effect of Cisplatin and Doxorubicin, and an advanced drug delivery system.

Pressurized Intraperitoneal Aerosol Chemotherapy (Oxaliplatin) for Unresectable Colorectal Peritoneal Metastases: A Multicenter, Single-Arm, Phase II Trial (CRC-PIPAC)

BACKGROUND

Despite its increasing use, pressurized intraperitoneal aerosol chemotherapy with oxaliplatin (PIPAC-OX) has never been prospectively investigated as a palliative monotherapy for colorectal peritoneal metastases in clinical trials. This trial aimed to assess the safety (primary aim) and antitumor activity (key secondary aim) of PIPAC-OX monotherapy in patients with unresectable colorectal peritoneal metastases.

METHODS

In this two-center, single-arm, phase II trial, patients with isolated unresectable colorectal peritoneal metastases in any line of palliative treatment underwent 6-weekly PIPAC-OX (92 mg/m²). Key outcomes were major treatment-related adverse events (primary outcome), minor treatment-related adverse events, hospital stay, tumor response (radiological, biochemical, pathological, ascites), progression-free survival, and overall survival.

RESULTS

Twenty enrolled patients underwent 59 (median 3, range 1-6) PIPAC-OX procedures. Major treatment-related adverse events occurred in 3 of 20 (15%) patients after 5 of 59 (8%) procedures (abdominal pain, intraperitoneal hemorrhage, iatrogenic pneumothorax, transient liver toxicity), including one possibly treatment-related death (sepsis of unknown origin). Minor treatment-related adverse events occurred in all patients after 57 of 59 (97%) procedures, the most common being abdominal pain (all patients after 88% of procedures) and nausea (65% of patients after 39% of procedures). Median hospital stay was 1 day (range 0-3). Response rates were 0% (radiological), 50% (biochemical), 56% (pathological), and 56% (ascites). Median progression-free and overall survival were 3.5 months (interquartile range [IQR] 2.5-5.7) and 8.0 months (IQR 6.3-12.6), respectively.

CONCLUSIONS

In patients with unresectable colorectal peritoneal metastases undergoing PIPAC-OX monotherapy, some major adverse events occurred and minor adverse events were common. The clinical relevance of observed biochemical, pathological, and ascites responses remains to be determined, especially since radiological response was absent.

Current status of conversion surgery for stage IV gastric cancer

Palliative chemotherapy with best supportive care is a mainstay for patients with gastric cancer (GC) and distant metastasis. However, with advances in GC chemotherapy, multimodal treatment, including perioperative chemotherapy plus conversion surgery, has attracted attention as a new strategy to improve the outcome of patients with stage IV disease. Conversion surgery is defined as surgical treatment aimed at R0 resection after a good response to induction chemotherapy for tumors originally considered unresectable or marginally resectable for technical and/or oncological reasons. Various biological characteristics differ, depending on each metastatic condition in stage IV GC. The main metastatic pathways of GC can be divided into three categories: lymphatic, hematogenous, and peritoneal. In each category, considerable historical data on conversion surgery have demonstrated the benefits of individualized approaches. However, owing to the diversity of these conditions, a common definition, including the choice of induction chemotherapy, optimal timing of resection, and eligibility for conversion surgery, has not been established among surgical oncologists. Thus, we explore the current and future treatment options by reviewing the literature on this controversial topic comprehensively.

Pressurized Intraperitoneal Aerosol Chemotherapy for Colorectal Peritoneal Metastases

BACKGROUND

The benefit of repetitive PIPAC specifically in CPM patients has yet to be demonstrated in terms of oncological and functional outcomes.

OBJECTIVE

The aim of this study was to evaluate the outcome of patients with non-resectable colorectal peritoneal metastases (CPM) treated with pressurized intraperitoneal aerosol chemotherapy (PIPAC).

METHODS

We conducted an analysis of a prospective single-center database of all CPM patients who underwent PIPAC with oxaliplatin 92 mg/m² body surface (PIPAC-Ox). The outcome criteria were adverse events (Common Terminology Criteria for Adverse Events version 4.0), Peritoneal Regression Grading Score (PRGS), and survival.

RESULTS

Overall, 102 patients with a median age of 64 years (33-88) were scheduled for PIPAC-Ox. Access to the abdominal cavity for the first application failed in 22/102 (21.6%) patients. A total of 185 PIPACs were performed, with 26/102 (25.5%), 20/102 (19.6%), 17/102 (16.7%), and 17/102 (16.7%) patients undergoing one, two, three, and four or more PIPACs, respectively. Perioperative overall morbidity/mortality Grade I-V occurred in 14 (7.6%), 29 (15.8%), 6 (3.2%), 1 (0.5%), and 1 (0.5%) patient without significant differences between each cycle. Of 27 patients who underwent three or more PIPACs, 20/102 (19.6%) had major/complete CPM regression (PRGS 1-2). In a multivariate analysis, independent predictive factors for > 12 months' survival following the first PIPAC-Ox administration were three or more PIPACs (odds ratio [OR] 4.5, 95% confidence interval [CI] 1.35-15.2; p = 0.014) and younger patient age (OR 1.058, 95% CI 1.00-1.12; p = 0.039).

CONCLUSIONS

Repetitive PIPAC-Ox for CPM patients, alone or combined with perioperative systemic chemotherapy, is feasible. Our data suggest that three or more consecutive PIPAC-Ox cycles for advanced CPM can improve survival.

Pressurized Intraperitoneal Aerosol Chemotherapy: The Road from Promise to Proof

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is an innovative drug delivery technique invented to be used for the treatment of peritoneal metastasis. Its application gained popularity over the past years. Several prospective clinical trials are being conducted to determine efficacy and safety. At this moment, there remain many challenges to overcome before PIPAC can be widely adopted in clinical practice.See related article by Kim et al., p. 1875.

Enhanced intraperitoneal delivery of charged, aerosolized curcumin nanoparticles by electrostatic precipitation

Aims: To investigate the potential of curcumin-loaded polylactic-co-glycolic acid nanoparticles (CUR-PLGA-NPs), alone and with electrostatic precipitation, for improving tissue uptake during pressurized intraperitoneal aerosol chemotherapy (PIPAC). Methods: Positively and negatively charged CUR-PLGA-NPs were delivered as PIPAC into inverted bovine urinary bladders ex vivo. The experiment was repeated with the additional use of electrostatic precipitation pressurized intraperitoneal aerosol chemotherapy (electrostatic PIPAC). Results: Positively charged CUR-PLGA-NPs increased depth of tissue penetration by 81.5% and tissue concentration by 80%. Electrostatic precipitation further improved the uptake of positively charged CUR-PLGA-NPs by 41.8%. Conclusion: The combination of positive charge and electrostatic precipitation have significant potential to improve tissue uptake of nanoparticles during intraperitoneal chemotherapy.

Peritoneal Metastases From Colorectal Cancer: Defining and Addressing the Challenges

The presence of peritoneal metastases (PM) in patients with colorectal cancer (CRC) is associated with an extremely poor prognosis. The diagnosis of PM is challenging, resulting in an underestimation of their true incidence. While surgery can be curative in a small percentage of patients, effective treatment for non-operable PM is lacking, and clinical and pre-clinical studies are relatively sparse. Here we have defined the major clinical challenges in the areas of risk assessment, detection, and treatment. Recent developments in the field include the application of organoid technology, which has generated highly relevant pre-clinical PM models, the application of diffusion-weighted MRI, which has greatly improved PM detection, and the design of small clinical proof-of-concept studies, which allows the efficient testing of new treatment strategies. Together, these developments set the stage for starting to address the clinical challenges. To help structure these efforts, a translational research framework is presented, in which clinical trial design is based on the insight gained from direct tissue analyses and pre-clinical (organoid) models derived from CRC patients with PM. This feed-forward approach, in which a thorough understanding of the disease drives innovation in its clinical management, has the potential to improve outcome in the years to come.

Establishment of a Mouse Ovarian Cancer and Peritoneal Metastasis Model to Study Intraperitoneal Chemotherapy

Simple Summary

Intraperitoneal chemotherapy (IPC) is a locoregional treatment option in patients with peritoneal metastases (PM). Small animal models are valuable research tools allowing for rapid, reproducible, and inexpensive study and optimization of different forms of IPC. Here, we present a mouse model of ovarian cancer-derived PM and demonstrate its suitability for various modes of IPC, including pressurized intraperitoneal chemotherapy (PIPAC) using a micro-nozzle for aerosolized drug delivery.

Abstract

Intraperitoneal chemotherapy (IPC) is a locoregional treatment option in patients with peritoneal metastases (PM). Here, we present an ovarian cancer (OC)-derived PM mouse model for the study of different forms of IPC. Xenograft cell proliferation (luciferase-transfected OVCAR3 and SKOV3 clones) and growth kinetics were assessed using PET scan, bioluminescence imaging (BLI), and histological tumor analysis. Liquid IPC was achieved by intraperitoneal injection with/without capnoperitoneum (6–7 mmHg). Pressurized intraperitoneal aerosol chemotherapy (PIPAC) was mimicked using an intratracheal drug aerosol administration system (micro-nozzle), which, as demonstrated by ex vivo granulometric analysis using laser diffraction spectrometry, produced a polydisperse, bimodal aerosol with a volume-weighted median diameter of (26.49 ± 2.76) µm. Distribution of Tc-99m-labeled doxorubicin in mice was characterized using SPECT and was dependent on the delivery mode and most homogeneous when the micro-nozzle was used. A total of 2 mg doxorubicin per kg body weight was determined to be the optimally effective and tolerable dose to achieve at least 50% tumor reduction. Repeated PIPAC (four times at seven-day-intervals) with doxorubicin in SKOV3-luc tumor-bearing mice resulted in halted tumor proliferation and tumor load reduced after the second round of PIPAC versus controls and the number of tumor nodules was significantly reduced (27.7 ± 9.5 vs. 57.3 ± 9.5; p = 0.0003). Thus, we established the first mouse model of OC PM for the study of IPC using a human xenograft with SKOV3 cells and an experimental IPC setup with a miniaturized nozzle. Repeated IPC was feasible and demonstrated time-dependent anti-tumor activity.

Loco-regional drug delivery in oncology: current clinical applications and future translational opportunities

Introduction: Drug-based treatment regimens for cancer are often associated with off-target toxic side effects and low penetration of the drug at the tumor site leading to patient morbidity and limited efficacy. Loco-regional drug delivery has the potential to increase efficacy while concomitantly reducing toxicity.Areas covered: Clinical applications using loco-regional delivery include intra-arterial drug delivery in retinoblastoma, direct intra-tumoral (IT) injection of ethanol for ablation in hepatocellular carcinoma (HCC) and the use of HIPEC in peritoneal carcinomas. In recent years, there has been a significant increase in both approved products and clinical trials, with a particular emphasis on drug delivery platforms such as drug-eluting beads for HCC and hydrogel platforms for intravesical delivery in bladder cancer.Expert opinion: Development of loco-regional drug-delivery systems has been slow, limited by weak clinical data for early applications and challenges relating to dosing, delivery and retention of drugs at the site of action. However, there is increasing focus on the potential of loco-regional drug delivery when combined with bespoke drug-delivery platforms. With the growth in immunotherapies, the use of IT delivery to drive priming of the anti-tumor response has opened up a new field of opportunity for loco-regional drug delivery.

Laparoscopic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for limited peritoneal metastasis. The PSOGI international collaborative registry

INTRODUCTION

A laparoscopic approach for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (L-CRS+HIPEC) in highly selected patients has been reported in small cohorts with a demonstrable reduction in length of stay and post-operative morbidity. This study aims to analyse individual patient data from these international centres collected through the Peritoneal Surface Oncology Group International (PSOGI) L-CRS+HIPEC registry.

METHODS

An international registry was designed through a networking database (REDCAP®). All centres performing L-CRS+HIPEC were invited through PSOGI to submit data on their cases. Patient's characteristics, postoperative outcomes and survival were analysed.

RESULTS

Ten international centres contributed a total of 143 L-CRS+HIPEC patients during the study period. The most frequent indication was low grade pseudomyxoma peritonei in 79/143 (55%). Other indications were benign multicyst mesothelioma in 21/143(14%) and peritoneal metastasis from colon carcinoma in 18/143 (12,5%) and ovarian carcinoma in 13/143 (9%). The median PCI was 3 (2-5). The median length of stay was 6 (5-10) days, with 30-day major morbidity rate of 8.3% and 30-day mortality rate of 0.7%. At a median follow-up of 37 (16-64) months 126/143 patients (88.2%) were free of disease.

CONCLUSIONS

Analysis of these data demonstrates that L-CRS+HIPEC is a safe and feasible procedure in highly selected patients with limited peritoneal disease when performed at experienced centres. While short to midterm outcomes are encouraging in patients with less invasive histology, longer follow up is required before recommending it for patients with more aggressive cancers with peritoneal dissemination.

Standardizing training for Pressurized Intraperitoneal Aerosol Chemotherapy

BACKGROUND

PIPAC is a novel mode of intraperitoneal drug delivery for patients with peritoneal cancer (PC). PIPAC is a safe treatment with promising oncological results. Therefore, a structured training program is needed to maintain high standards and to guarantee safe implementation.

METHODS

An international panel of PIPAC experts created by means of a consensus meeting a structured 2-day training course including essential theoretical content and practical exercises. For every module, learning objectives were defined and structured presentations were elaborated. This structured PIPAC training program was then tested in five courses.

RESULTS

The panel consisted of 12 experts from 11 different centres totalling a cumulative experience of 23 PIPAC courses and 1880 PIPAC procedures. The final program was approved by all members of the panel and includes 12 theoretical units (45 min each) and 6 practical units including dry-lab and live surgeries. The panel finalized and approved 21 structured presentations including the latest evidence on PIPAC and covering all mandatory topics. These were organized in 8 modules with clear learning objectives to be tested by 12 multiple-choice questions. Lastly, a structured quantifiable (Likert scale 1-5) course evaluation was created. The new course was successfully tested in five courses with 85 participants. Mean overall satisfaction with the content was rated at 4.79 (±0.5) with at 4.71 (±0.5) and at 4.61 (±0.7), respectively for course length and the balance between theory and practice.

CONCLUSIONS

The proposed PIPAC training program contains essential theoretical background and practical training enabling the participants to safely implement PIPAC.

Pressurized Intraperitoneal Aerosol Chemotherapy Enhanced by Electrostatic Precipitation (ePIPAC) for Patients with Peritoneal Metastases

BACKGROUND

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new mode of intraperitoneal chemotherapy administration that can potentially be improved by the addition of electrostatic precipitation (ePIPAC). This study aimed to describe the procedural details of ePIPAC and to analyze its safety for patients with nonresectable peritoneal metastasis as well as their tolerance and response to this treatment.

METHODS

This retrospective cohort study included consecutive patients treated with ePIPAC in three centers from April 2019 to April 2020. The toxicities of each patient were assessed using the Common Terminology Criteria for Adverse Events (CTCAE). Complications were documented according to the Clavien classification. Quality of life (QoL) was assessed using EORTC-QLQ-C30, and the peritoneal regression grading score (PRGS) was used to grade histologic responses. Further surrogates for responses were the Peritoneal Cancer Index (PCI), ascites, and symptoms.

RESULTS

Overall, 69 patients received 147 ePIPACs with oxaliplatin (n = 34) or cisplatin/doxorubicin (n = 35) mainly for colorectal (n = 25), ovarian (n = 14), and gastric (n = 13) primary cancers. Systemic chemotherapy was used in the treatment of 54 patients (76%). The median electrostatic therapy time was 12 min (range 6-30 min). The overall and major CTCAE toxicity rates were respectively 24.6% and 15.9%. The postoperative complications rate according to Clavien classification was 4.7%. The responses of 22 patients who had three or more ePIPAC treatments were evaluated as follows: PCI (16 vs 14; p = 0.4), ascites (320 vs 98 ml; p = 0.1), and PRGS (2.23 vs 1.73; p = 0.15). The complete (PRGS1) and major (PRGS2) histologic responses at the third ePIPAC were respectively 38.5% and 53.8%. Overall QoL was stable during the first ePIPACs.

CONCLUSION

Repetitive ePIPACs were safe and well tolerated for patients with unresectable peritoneal metastasis.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) for rare gynecologic indications: peritoneal metastases from breast and endometrial cancer

BACKGROUND

Peritoneal metastasis (PM) in patients with breast (BC) and endometrial cancer (EC) is rare and treatment options are limited. Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC) has demonstrated efficacy against PM from various cancers, but its efficacy in BC/EC patients is unknown.

METHODS

Retrospective cohort study of patients with PM from BC/EC undergoing PIPAC with doxorubicin 1.5 mg/m² and cisplatin 7.5 mg/m². Data were collected within an international prospective PIPAC registry. Study outcomes were microscopic tumor regression grade (TRG), survival, adverse events (CTCAE), and quality of life (QoL).

RESULTS

150 PIPAC procedures in 44 patients (BC/EC = 28/16; mean age 58.8 ± 10.1 and 63.2 ± 10.1 years, respectively) were analyzed. The mean number of PIPACs per patient was 3 (range 0-9) and 3.5 (range 0-10), respectively. Primary/secondary non-access occurred in 4/3 of 150 (5%) procedures. PIPAC induced objective tumor regression as demonstrated by repetitive PM biopsies in 73% (32/44) of patients. Peri- and postoperative CTCAE grade 3 and 4 complications were observed in 12/150 (8%) of procedures. No grade 5 event was observed. After a median follow up of 5.7 (IQR 2.7-13.0) months, overall median survival was 19.6 (95% CI: 7.8-31.5) months (from first PIPAC). QoL indicators (general health, nausea, fatigue, constipation, pain, dyspnea, social, cognitive, emotional, and physical functioning) all improved or were maintained throughout PIPAC treatments.

CONCLUSIONS

Repetitive intraperitoneal chemotherapy with PIPAC is feasible and safe in patients with PM from BC and EC. PIPAC induces significant histological regression of PM while maintaining QoL.

Technique of pressurized intrathoracic aerosol chemotherapy (PITAC) for malignant pleural effusion

Objectives

Malignant pleural effusion (MPE) is a devastating evolution of several malignancies. Pressurized intrathoracic aerosol chemotherapy (PITAC) might be a novel therapy option in MPE.

Methods

PITAC is considered for patients with MPE with a performance status <2 and without other metastatic sites. General anesthesia is administered and a double-lumen bronchial tube is inserted. The patient is placed in a lateral decubitus position, and the operation is performed after ipsilateral lung exclusion. Two 12-mm balloon trocars are inserted—one in the seventh intercostal space in the mid-axillary line and one in the fifth intercostal space in the anterior axillary line. Extent of pleural disease and volume of MPE are documented. MPE is removed and parietal pleural biopsy are performed. An intrathoracic pressure of 12 mmHg CO₂ is established, and a combination of Cisplatin (10.5 mg/m² in a total volume of 150 cc NaCl 0.9%) and Doxorubicin (2.1 mg/m² in a total volume of 50 cc NaCl 0.9%) are aerosolized via nebulizer in the pleural cavity. Vital signs and nebulization are remote-controlled. After 30 min, the remaining toxic aerosol is exhausted using a closed surgical smoke evacuation system. A 24Fr chest tube is inserted in postero-apical position with continuous negative pressure of 20 cm H₂O. When needed, PITAC may be repeated every six weeks in alternate with systemic chemotherapy.

Results

In our hands, the technique above has shown to be feasible and safe.

Conclusions

Further studies are needed to assess the potential symptomatic and oncological benefits of PITAC in MPE.

PIPAC-OX: A Phase I Study of Oxaliplatin-Based Pressurized Intraperitoneal Aerosol Chemotherapy in Patients with Peritoneal Metastases

PURPOSE

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a novel laparoscopic, intraperitoneal chemotherapy delivery technique aiming to improve drug distribution and tissue penetration to treat peritoneal metastases. Thus far, PIPAC oxaliplatin is conducted at an arbitrary dose of 92 mg/m². We conducted a phase I study to establish safety and tolerability.

PATIENTS AND METHODS

We used a 3+3 dose-escalation design of PIPAC oxaliplatin for patients with peritoneal metastases from gastrointestinal tumors, after failure of at least first-line chemotherapy. Dose levels were planned at 45, 60, 90, and 120 mg/m².

RESULTS

This study included 16 patients with 24 PIPAC procedures (8 gastric; 5 colorectal; and 1 gallbladder, pancreas, and appendix cancer each). Median age and peritoneal cancer index (PCI) score were 62 years and 17, respectively. Two patients developed pancreatitis (grade 2 and 3) at 45 mg/m², necessitating cohort expansion. Another patient developed grade 2 pancreatitis at 90 mg/m². There were no other dose-limiting toxicities, and the highest-dose cohort (120 mg/m²) tolerated PIPAC well. Pharmacokinetic analyses demonstrated good linearity between dose and maximum concentration (r ² = 0.95) and AUC (r ² = 0.99). On the basis of RECIST, 62.5% and 50% had stable disease after one and two PIPAC procedures, respectively. A total of 8 patients underwent two PIPAC procedures, with improvement of median PCI and peritoneal regression grade score from 15 to 12 and 2.5 to 2.0, respectively.

CONCLUSIONS

The recommended phase II dose is 120 mg/m². Future studies should further delineate the efficacy and role of PIPAC oxaliplatin for peritoneal metastases.See related commentary by de Jong et al., p. 1830.

A phase I dose-escalation study of oxaliplatin delivered via a laparoscopic approach using pressurised intraperitoneal aerosol chemotherapy for advanced peritoneal metastases of gastrointestinal tract cancers

OBJECTIVE

The objectives were to define the maximum tolerated dose (MTD), safety profile and pharmacokinetics (PKs) of intraperitoneal oxaliplatin delivered by pressurised intraperitoneal aerosol chemotherapy (PIPAC) in patients with advanced peritoneal carcinomatosis from gastrointestinal tract cancers.

METHODS

PIPAC was applied every 4-6 weeks, for 5 cycles, in a phase I dose-escalation study using a 3 + 3 design. The first dose level was 90 mg/m² with planned increases of 50 mg/m² per level. Platinum concentration was measured in plasma, tissues and intraperitoneal fluid samples. The trial was registered at ClinicalTrials.gov (NCT03294252).

RESULTS

Ten patients with 33 PIPAC sessions were included. No dose limiting toxicity (DLT) occurred at 90 mg/m² and two at 140 mg/m². The MTD was therefore set at 90 mg/m². Overall treatment included a median number of three PIPAC sessions (range: 1-5) and secondary complete cytoreductive surgery for two patients. Overall safety showed 67 grade I-II and 11 grade III-IV toxicities, usually haematologic, digestive (nausea/vomiting, abdominal pain), and fatigue. Oxaliplatin concentrations were three- to four-fold higher in tissue in contact with aerosol than in muscle without contact. At 140 mg/m², the plasma oxaliplatin concentration was high with Cmax and area under the curve (AUC)_0-48h of 1035 μg/l and 9028 μg h/L, respectively.

CONCLUSIONS

The MTD of oxaliplatin during PIPAC is 90 mg/m². PK data demonstrate a high tumour concentration and a significant systemic absorption.

Multimodality Treatment in Metastatic Gastric Cancer: From Past to Next Future

Gastric cancer (GC) still remains an incurable disease in almost two-thirds of the cases. However, a deeper knowledge of its biology in the last few years has revealed potential biomarkers suitable for tailored treatment with targeted agents. This aspect, together with the improvement in early supportive care and a wiser use of the available cytotoxic drugs across multiple lines of treatment, has resulted in incremental and progressive survival benefits. Furthermore, slowly but surely, targeted therapies and immune checkpoint inhibitors are revising the therapeutic scenario even in metastatic GC and especially in particular subgroups. Moreover, important study results regarding the possible role of an integrated approach combining systemic, surgical, and locoregional treatment in carefully selected oligometastatic GC patients are awaited. This review summarizes the state-of-the-art and the major ongoing trials involving a multimodal treatment of metastatic GC.

Prognostic impact of combined progression index based on peritoneal grading regression score and peritoneal cytology in peritoneal metastasis

AIMS

The peritoneal regression grading score (PRGS) and peritoneal cytology (PC) assess response to chemotherapy in peritoneal metastasis (PM) in a setting of palliative treatment by pressurized intraperitoneal aerosol chemotherapy (PIPAC). Progression has been defined as an increase of PRGS between first and third PIPAC procedures (iPRGS). iPRGSand positive peritoneal cytology were not associated with prognostic impact. These results may be explained by a lack of statistical power. Also, it is not known whether the mean or the highest PRGS among taken peritoneal biopsies bears the highest clinical value. We therefore conducted the largest prospective study to investigate the prognostic impact of PGRS, PC, and their combination, designated as combined progression index (CPI).

METHODS AND RESULTS

Patients with PM who underwent >3 PIPAC (n = 112) between December 2016 and February 2019 were prospectively included. A significant difference in OS and PFS according to CPI (used highest value of PRGS) was found (OS: CPI-, 83.3, 95% CI [49.8; NA] vs. CPI+, 48.1, 95% CI [38.5; 66.4] months; and PFS (respectively, 59.7, 95% CI [43.0; 96.0] vs. 33.7, 95% CI [30.4; 44.2] months). PRGS or PC had no independent prognostic impact. CPI+ was an independent predictor of worse prognosis, in OS (HR = 5.24, 95% CI [2.07; 13.26]), and PFS (HR = 4.41, 95% CI [1.40; 13.88]).

CONCLUSIONS

The CPI based on highest PRGS and PC was found to be independently associated with a worse prognosis for OS and for PFS in the setting of peritoneal metastasis. These results indicate that it should be of interest to systematically take peritoneal fluid for cytological examination and to implement the CPI in the therapeutic decision-making process in the context of PIPAC.

Systematic review of patient reported outcomes (PROs) and quality of life measures after pressurized intraperitoneal aerosol chemotherapy (PIPAC)

Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC) constitutes a recently described surgical technique to administer chemotherapy directly to the peritoneum, under pressure, for patients with peritoneal metastasis (PM). The purpose of an oncological treatment is to improve survival but without altering the patient's quality of life. The aim of this review was to evaluate patient-reported outcomes (PRO) after PIPAC for patients with PM. This systematic review was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Between January 1, 2013, and January 1, 2020, studies were selected according to the following criteria: "pressurized intraperitoneal aerosol chemotherapy" OR "PIPAC" AND "patient-reported outcomes" OR "PRO" OR "Quality of life". In this review, 959 PIPAC and five PITAC (Pressurized IntraThoracic Aerosol Chemotherapy) were performed in 425 patients. We highlight the prominent application of generic EORTC QLQ-C30 followed by SF-36 in this review. The PROs according to the EORTC-QLQ-C30 global health score and based on symptom and function scores were stable across most studies. Moreover, PIPAC has improved the PRO of altered patients in two studies. Among 425 patients, the mortality rate was 0.7% and adverse events of Common Terminology Criteria of Adverse Events grade 3 and grade 4 were 9.6% and 1.6%, respectively. We synthesised current research on PROs among patients with PM. This review increases our understanding of the PIPAC strategy from the patient perspective. The implementation of PROs can be complex but will be essential in delivering quality care.

Current practice of pressurized intraperitoneal aerosol chemotherapy (PIPAC): Still standardized or on the verge of diversification?

BACKGROUND

PIPAC is a new treatment modality for peritoneal cancer which has been practiced and evaluated until very recently by few academic centers in a highly standardized manner. Encouraging oncological outcomes and the safety profile have led to widespread adoption. The aim of this study was to assess current PIPAC practice in terms of technique, treatment and safety protocol, and indications.

METHODS

A standardized survey with 82 closed-ended questions was sent online to active PIPAC centers which were identified by help of PIPAC training centers and the regional distributors of the PIPAC-specific nebulizer. The survey inquired about center demographics (n = 8), technique (n = 34), treatment and safety protocol (n = 34), and indications (n = 6).

RESULTS

Overall, 62 out of 66 contacted PIPAC centers answered the survey (response rate 93%). 27 centers had performed >60 PIPAC procedures. A consensus higher than 70% was reached for 37 items (50%), and higher than 80% for 28 items (37.8%). The topics with the highest degree of consensus were safety and installation issues (93.5% and 80.65%) while chemotherapy and response evaluation were the least consensual topics (63.7 and 59.6%). The attitudes were not influenced by volume, PIPAC starting year, type of activity, or presence of peritoneal metastases program.

CONCLUSION

Homogeneous treatment standards of new techniques are important to guarantee safe implementation and practice but also to allow comparison between cohorts and multi-center analysis of merged data including registries. Efforts to avoid diversification of PIPAC practice include regular update of the PIPAC training curriculum, targeted research and a consensus statement.

Initial Single-center Experience of PIPAC in Patients With Unresectable Peritoneal Metastasis

INTRODUCTION

Peritoneal carcinomatosis remains a condition with poor prognosis and limited therapeutic options. Pressurized Intrapertioneal Aerosol Chemotherapy (PIPAC) has been developed as a new tool for delivering intraperitoneal chemotherapy with low morbidity. The aim of this study was to evaluate the initial experience of PIPAC in patients with peritoneal carcinomatosis at our hospital.

METHODS

A prospective study between January 2019 and February 2020 was carried at a tertiary public hospital. Primary tumor, ascites volume, PCI, chemotherapy regimen, operative time, morbidity, length of hospital stay and mortality were recorded for analysis.

RESULTS

We analyzed 9 PIPAC procedures performed in 5patients. Median PCI was 27.6 (24-35). Median surgical time was 93minutes (70-125). Only one adverse event occurred out of 9 procedures (Clavien-DindoII). Median length of hospital stay was 2days (1-4). Mortality was 0%.

CONCLUSION

PIPAC seems to be a feasible and safe procedure to treat peritoneal carcinomatosis, with low morbidity and short hospital stay.

Restricted access to innovative surgical technique related to a specific training, is it ethical? Example of the PIPAC procedure. A systematic review and an experts survey

OBJECTIVE

Using the example of Pressurized Intra Peritoneal Aerosol Chemotherapy (PIPAC), we analyse the development model of this procedure and provide an ethical analysis of the involvement of the industry in a new development.

SUMMARY BACKGROUND DATA

In the case of breakthrough innovation, medical training is essential for safe use of the new procedure. In some cases, pharmaceutical companies decide to organise this training. But when it becomes the only training opportunity to use the device, scientists and clinicians could be exposed to a conflict of interest?

METHODS

We performed a literature review of PIPAC publications using the STROBE criteria. Then, we conducted interviews with an expert panel to analyse the ethical impact of involvement of the industry in the development of the PIPAC procedure.

RESULTS

The number of publications has increased every year since the first publication in Germany, where the technology was developed in 2013. The scientific production was of good quality, with a mean STROBE score of 18.2 ± 2.4 out of 22 points. Ten of the 33 included studies declared a conflict of interest. From the interviews, the main axe concerning the implication of the industry was the training model. The company had decided that only trained and approval surgeon could perform the PIPAC procedure. All four interviewed practitioners agreed that it was initially a good way to implement the procedure safely, but later they felt uncomfortable about the control and validation by the industry.

CONCLUSION

Based on the growing number of published papers from a growing number of international centres, the controlled training model is not limiting. However, the different levels of conflict of interest complicate transparency, and we postulated that this development model is limited to the beginning of the procedure diffusion. CLINICALTRIAL.

GOV REGISTRATION

NCT04341337.

Electrostatic Intraperitoneal Aerosol Delivery of Nanoparticles: Proof of Concept and Preclinical Validation

There is an increasing interest in intraperitoneal delivery of chemotherapy as an aerosol in patients with peritoneal metastasis. The currently used technology is hampered by inhomogenous drug delivery throughout the peritoneal cavity because of gravity, drag, and inertial impaction. Addition of an electrical force to aerosol particles, exerted by an electrostatic field, can improve spatial aerosol homogeneity and enhance tissue penetration. A computational fluid dynamics model shows that electrostatic precipitation (EP) results in a significantly improved aerosol distribution. Fluorescent nanoparticles (NPs) remain stable after nebulization in vitro, while EP significantly improves spatial homogeneity of NP distribution. Next, pressurized intraperitoneal chemotherapy with and without EP using NP albumin bound paclitaxel (Nab-PTX) in a novel rat model is examined. EP does not worsen the effects of CO₂ insufflation and intraperitoneal Nab-PTX on mesothelial structural integrity or the severity of peritoneal inflammation. Importantly, EP significantly enhances tissue penetration of Nab-PTX in the anatomical regions not facing the nozzle of the nebulizer. Also, the addition of EP leads to more homogenous peritoneal tissue concentrations of Nab-PTX, in parallel with higher plasma concentrations. In conclusion, EP enhances spatial homogeneity and tissue uptake after intraperitoneal nebulization of anticancer NPs.

Pressurized intraperitoneal aerosol chemotherapy with cisplatin and doxorubicin or oxaliplatin for peritoneal metastasis from pancreatic adenocarcinoma and cholangiocarcinoma

Background

Systemic chemotherapy for pancreatic adenocarcinoma (PDAC) and cholangiocarcinoma (CC) with peritoneal metastases (PM) is affected by several pharmacological shortcomings and low clinical efficacy. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is expected to maximize exposure of peritoneal nodules to antiblastic agents. This study aims to evaluate safety and efficacy of PIPAC for PM of PDAC and CC origin.

Methods

This is a retrospective analysis of consecutive PDAC and CC cases with PM treated with PIPAC at two European referral centers for peritoneal disease. We prospectively recorded from August 2016 to May 2019 demographic, clinical, surgical, and oncological data. We performed a feasibility and safety assessment and an efficacy analysis based on clinical and pathological regression.

Results

Twenty patients with PM from PDAC (14) and CC (six) underwent 45 PIPAC administrations. Cisplatin-doxorubicin or oxaliplatin were administered to eight and 12 patients, respectively. We experienced one intraoperative complication (small bowel perforation) and 18 grade 1-2 postoperative adverse events according to Common Terminology Criteria for Adverse Events version 4.0. A pathological regression was recorded in 50% of patients (62% in the cisplatin-doxorubicin cohort and 42% in the oxaliplatin one). Median survival from the first PIPAC was 9.7 and 10.9 months for PDAC and CC, respectively.

Conclusion

PIPAC resulted feasible and safe without relevant toxicity issues, with both cisplatin-doxorubicin and oxaliplatin. The pathological response observed supports the evidence of antitumoral activity. Despite the study limitations, these outcomes are encouraging, recommending PIPAC in prospective, controlled trials in the palliative setting or the first line chemotherapy for PM from PDAC and CC.

Safety, pharmacokinetics and tissue penetration of PIPAC paclitaxel in a swine model

INTRODUCTION

Peritoneal carcinomatosis is difficult to treat. Pressurized Intra-Peritoneal Aerosolised Chemotherapy (PIPAC) is a novel method of delivering chemotherapy to the peritoneal cavity, aiming for homogenous and deeper drug distribution. To date, limited chemotherapeutics have been used with promising results. Here, we evaluate the pharmacokinetics, peritoneal tissue drug concentration, penetration, and short-term safety of PIPAC using solvent-based paclitaxel in swine to guide clinical trials.

MATERIALS AND METHODS

PIPAC solvent-based paclitaxel was administered at 60, 30, and 15mg/m² for 3 cohorts. Each PIPAC procedure was followed by intravenous (IV) administration of the same dose of solvent-based paclitaxel on Day 7, serving as control for pharmacokinetic comparison in the same pig. Safety and toxicity were evaluated by clinical assessment, blood counts and biochemistry. Blood samples were taken for pharmacokinetic analysis. Peritoneal biopsies were taken to measure tissue paclitaxel concentrations and distribution.

RESULTS

12 Yorkshire x Landrace pigs underwent trial procedures. With PIPAC, there was linear pharmacokinetics and lower systemic exposure to paclitaxel compared to IV administration. MALDI-MSI demonstrated concentration of paclitaxel at the peritoneal surface, with estimated 2 mm penetration. PIPAC paclitaxel had favorable toxicity profile. The most significant adverse event was neutropenia which was dose dependent, with absolute neutrophil count <1.0 × 10³/μL seen at the highest dose. One pig developed grade 2 hypersensitivity reaction during IV infusion and one death occurred during the PIPAC procedure, likely from anaphylaxis; these are known potential adverse events mandating standard precautions and monitoring.

CONCLUSION

PIPAC paclitaxel at 15mg/m² may be considered for a Phase I study.

A Pilot Study of the Predictive Potential of Chemosensitivity and Gene Expression Assays Using Circulating Tumour Cells from Patients with Recurrent Ovarian Cancer

Circulating tumour cells (CTCs) from liquid biopsies are under current investigation in several cancers, including epithelial ovarian cancer (EOC) but face significant drawbacks in terms of non-standardised methodology, low viable cell numbers and accuracy of CTC identification. In this pilot study, we report that chemosensitivity assays using liquid biopsy-derived metastatic EOC CTCs, from 10 patients, nine with stage IIIC and one with stage IV disease, in progression after systemic chemotherapy, submitted for hypoxic isolated abdominal perfusion (HAP), are both feasible and useful in predicting response to therapy. Viable metastatic EOC CTCs (>5 cells/mL for all 10 blood samples), enriched by transient culture and identified by reverse transcription polymerase chain reaction (RT-PCR) and indirect immunofluorescence (IF), were subjected to flow cytometry-based Annexin V-PE assays for chemosensitivity to several chemotherapeutic agents and by RT-PCR for tumour gene expression profiling. Using a cut-off value of >80% cell death, CTC chemosensitivity tests were predictive of patient RECIST 1.1 responses to HAP therapy associated with 100% sensitivity, 50% specificity, 33% positive predictive, 100% negative predictive and 60% accuracy values. We propose that the methodology employed in this study is feasible and has the potential to predict response to therapy, setting the stage for a larger study.

Nuclear MYH9-induced CTNNB1 transcription, targeted by staurosporin, promotes gastric cancer cell anoikis resistance and metastasis

Rationale: Peritoneal metastasis predicts poor prognosis of gastric cancer (GC) patients, and the underlying mechanisms are poorly understood. Methods: The 2-DIGE, MALDI-TOF/TOF MS and single-cell transcriptome were used to detect differentially expressed proteins among normal gastric mucosa, primary GC and peritoneal metastatic tissues. Lentiviruses carrying shRNA and transcription activator-like effector nuclease technology were used to knock down myosin heavy chain 9 (MYH9) expression in GC cell lines. Immunofluorescence, immune transmission electron microscopy, chromatin fractionation, co-immunoprecipitation, and assays for chromatin immunoprecipitation, dual luciferase reporter, agarose-oligonucleotide pull-down, flow cytometry and cell anoikis were performed to uncover nuclear MYH9-induced β-catenin (CTNNB1) transcription in vitro. Nude mice and conditional transgenic mice were used to investigate the findings in vivo. Results: We observed that MYH9 was upregulated in metastatic GC tissues and was associated with a poor prognosis of GC patients. Mechanistically, we confirmed that MYH9 was mainly localized in the GC cell nuclei by four potential nuclear localization signals. Nuclear MYH9 bound to the CTNNB1 promoter through its DNA-binding domain, and interacted with myosin light chain 9, β-actin and RNA polymerase II to promote CTNNB1 transcription, which conferred resistance to anoikis in GC cells in vitro and in vivo. Staurosporine reduced nuclear MYH9 S1943 phosphorylation to inhibit CTNNB1 transcription, Wnt/β-catenin signaling activation and GC progression in both orthotropic xenograft GC nude mouse and transgenic GC mouse models. Conclusion: This study identified that nuclear MYH9-induced CTNNB1 expression promotes GC metastasis, which could be inhibited by staurosporine, indicating a novel therapy for GC peritoneal metastasis.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) for unresectable peritoneal metastasis from gastric cancer

BACKGROUND

PIPAC is a recent approach with promising results for patients with peritoneal metastasis (PM). We aimed to evaluate survival and postoperative outcome of patients with unresectable PM from gastric origin treated with chemotherapy and PIPAC.

METHODS

A retrospective analysis of a prospective maintained PIPAC database was queried for all patients diagnosed with unresectable PM from gastric cancer who underwent PIPAC before 2018. PIPAC with Cisplatin 7.5 mg/m2 and doxorubicin 1.5 mg/m2 were given for 30 min at 6-week intervals. Outcome criteria were overall survival and adverse events according to (CTCAE) version4.0.

RESULTS

One hundred Sixty-three PIPAC were done in 42 consecutive patients. Twenty-two (52%) of the patients were female. Signet-ring cells were observed in 33/42 patients (78.6%). At the first PIPAC, median age was 51.5 years (32-74). Median PCI was 17 (1-39). Twenty (47.6%) patients underwent more than 2 lines of pre-PIPAC chemotherapy. All patients had systemic chemotherapy alternating with PIPAC. Median consecutive PIPAC procedures were 3 (1-12). Overall and major complications (CTCAE - III, IV) occurred in 10 (6.1%) and 5 procedures (3.1%), respectively. Two patients (4.7%) died within 30 days of a PIPAC procedure, one related to small bowel obstruction and a pulmonary embolism for the other. Overall Survival was 19.1 months. Six (14.3%) patients became resectable during treatment and underwent curative intent CRS and HIPEC.

CONCLUSIONS

PIPAC with low-dose cisplatin and doxorubicin is safe and feasible in association with systemic chemotherapy for gastric PM. Survival data are encouraging and justify further clinical studies in this indication.

An overview and update of hyperthermic intraperitoneal chemotherapy in ovarian cancer

INTRODUCTION

Despite, the strong rationale and evidence of the benefit of postoperative intraperitoneal chemotherapy in advanced ovarian cancer, it has not been widely adopted, mainly due to its high morbidity and logistical difficulties. Intraoperative hyperthermic intraperitoneal chemotherapy (HIPEC) is a more tolerable and technically feasible method of intraperitoneal chemotherapy, whereas other potential advantages include homogenous drug distribution, application before tumor regrowth and combination with hyperthermia, which is directly cytotoxic and enhances the efficacy of many drugs.

AREAS COVERED

In this review, the authors explain the rationale and indications for cytoreductive surgery (CRS) and HIPEC in advanced ovarian cancer. Data of major clinical studies, meta-analyses, and recent randomized trials are discussed.

EXPERT OPINION

After many encouraging clinical studies and meta-analyses, a recent randomized study demonstrated survival benefit for HIPEC during interval CRS in primary ovarian cancer, without increased morbidity, whereas another implied its benefit in recurrent ovarian cancer. Results of recently completed and numerous ongoing randomized studies will further determine the benefit of HIPEC in ovarian cancer at different time points. Patient selection and appraisal of the best protocols are crucial. The field of gynecological oncology will most likely evolve to include HIPEC eventually as a routine treatment for ovarian cancer.

Systemic chemotherapy and pressurized intraperitoneal aerosol chemotherapy (PIPAC): A bidirectional approach for gastric cancer peritoneal metastasis

BACKGROUND

Few patients affected by gastric cancer peritoneal metastasis (GCPM) are offered locoregional treatment, despite several proof-of-efficacy trials. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) has emerged in recent years as a promising tool to control peritoneal carcinomatosis. The combination of PIPAC with systemic chemotherapy may offer a greater clinical benefit than standard treatment alone.

METHODS

A single-center cohort of 28 consecutive patients affected by GCPM was scheduled for bidirectional treatment, comprising PIPAC and systemic chemotherapy, from September 2017 to September 2019. Data recorded included safety, efficacy and survival outcomes. Ascite volumes, the Peritoneal Cancer Index (PCI) and pathological response through the Peritoneal Regression Grading Score (PRGS) were compared in those patients who underwent more than one PIPAC procedure.

RESULTS

Forty-six PIPAC procedures were administered, with a mean of 1.7 PIPAC procedures per patient. The median time to resume systemic chemotherapy after PIPAC was 6 days (range 4-7). Concerning safety, two grade 3-4 CTCAE (Common Terminology Criteria for Adverse Events v4.0) toxicity events and one intraoperative complication were recorded. Thirteen patients repeated PIPAC. A pathological response was recorded in 61.5% of patients (one with complete and seven with partial regression). The median overall survival was 12.3 months in the overall population and 15.0 months in patients undergoing more than one PIPAC procedure.

CONCLUSIONS

A bidirectional approach for GCPM was feasible and safe, as the PIPAC procedure integrates well with several systemic chemotherapy regimens. The pathological response demonstrated the antitumoral efficacy of PIPAC. The proposed bidirectional approach may be further investigated in the first-line treatment of metastatic gastric cancer.

COVID-19: impact on colorectal surgery

AIM

The rapid spread of the COVID-19 pandemic has created unprecedented challenges for the medical and surgical healthcare systems. With the ongoing need for urgent and emergency colorectal surgery, including surgery for colorectal cancer, several questions pertaining to operating room (OR) utilization and techniques needed to be rapidly addressed.

METHOD

This manuscript discusses knowledge related to the critical considerations of patient and caregiver safety relating to personal protective equipment (PPE) and the operating room environment.

RESULTS

During the COVID-19 pandemic, additional personal protective equipment (PPE) may be required contingent upon local availability of COVID-19 testing and the incidence of known COVID-19 infection in the respective community. In addition to standard COVID-19 PPE precautions, a negative-pressure environment, including an OR, has been recommended, especially for the performance of aerosol-generating procedures (AGPs). Hospital spaces ranging from patient wards to ORs to endoscopy rooms have been successfully converted from standard positive-pressure to negative-pressure spaces. Another important consideration is the method of surgical access; specifically, minimally invasive surgery with pneumoperitoneum is an AGP and thus must be carefully considered. Current debate centres around whether it should be avoided in patients known to be infected with SARS-CoV-2 or whether it can be performed under precautions with safety measures in place to minimize exposure to aerosolized virus particles. Several important lessons learned from pressurized intraperitoneal aerosolized chemotherapy procedures are demonstrated to help improve our understanding and management.

CONCLUSION

This paper evaluates the issues surrounding these challenges including the OR environment and AGPs which are germane to surgical practices around the world. Although there is no single universally agreed upon set of answers, we have presented what we think is a balanced cogent description of logical safe approaches to colorectal surgery during the COVID-19 pandemic.

Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC)-directed treatment of peritoneal metastasis in end-stage colo-rectal cancer patients

Background

Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC) represents a novel approach to intraperitoneal chemotherapy. Hereby results, obtained with PIPAC in patients with advanced peritoneal metastasis (PM) from colorectal cancer (CRC), are presented.

Methods

Data from CRC patients (n = 24) included in the prospective PIPAC-OPC1 and PIPAC-OPC2 trials are reported. Oxaliplatin 92 mg/m² was administered at 4-6-week intervals. A CE certified nebulizer was used to aerosolize the chemotherapeutics. Outcome criteria were objective tumor response, survival and adverse events.

Results

Retrospective analysis of 74 PIPAC procedures carried out in 24 consecutive patients with PM from CRC included from October 2015 to February 2019. Five patients had still the primary tumor in situ, and 22 patients had received palliative systemic chemotherapy. Nineteen patients completed more than two PIPAC procedures, and objective tumor response according to the histological Peritoneal Regression Grading Score (PRGS) was observed in 67% of the patients, while 21% had stable disease. Four patients (21%) had complete response (mean PRGS = 1 and negative cytology). We recorded a median survival of 37.6 (range 7.3–48.9) months from the time of PM diagnosis, whereas it was 20.5 (range 0.13–34.7) months following the first PIPAC session. Minor postoperative complications were noted, and few were considered causally related to the PIPAC treatment. However, two cases of severe postoperative complications were recorded (urosepsis and iatrogenic bowel perforation).

Conclusions

PIPAC with low-dose oxaliplatin can induce objective tumor regression in selected patients with advanced PM from colorectal cancer.

Comparison between microcatheter and nebulizer for generating Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC)

Background

This study compares an endoscopic microcatheter and a nebulizer for delivering Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC).

Methods

This is an in vitro and ex vivo study in an established model (inverted bovine urinary bladder). Four parameters were compared to determine the performance of a micro-perforated endoscopic spray catheter vs. state-of-the art, nozzle technology: (1) surface coverage and pattern with methylene blue on blotting paper at three different distances; (2) median aerodynamic diameter (MAD) of aerosol droplets with three different solutions (H₂O, Glc 5% and silicon oil); (3) depth of tissue penetration of doxorubicin (DOX) and (4) tissue concentration of cisplatin (CIS) and DOX using standard clinical solutions.

Results

The spray area covered by the microcatheter was larger (p < 0.001) but its pattern was inhomogenous than with the nozzle technology. We found that aerosol droplets were larger in the test group than in the control group for all three solutions tested. Median tissue penetration of DOX was lower (980 µm) with the microcatheter than with the nebulizer (1235 µm) and distribution was more heterogeneous ( = 0.003) with the microcatheter. The median tissue concentration of DOX and CIS was lower and concentration of DOX was more heterogeneous with the microcatheter (p = 0.002).

Conclusions

This investigation has revealed that microcatheter technology generates larger aerosol droplet size, less drug tissue penetration and lower drug tissue concentration than the current nozzle technology. In the absence of clinical studies, use of microcatheters for delivering PIPAC can not be recommended at this stage.

Recent Advances in Intra-peritoneal Chemotherapy for Gastric Cancer

Peritoneal metastasis (PM) frequently occurs in patients with gastric cancer (GC) and confers a dismal prognosis despite advances in systemic chemotherapy. While systemic chemotherapy has poor peritoneal penetration, intraperitoneal (IP) chemotherapy remains sequestered, resulting in high peritoneal drug concentrations with less systemic side-effects. The first application of IP treatment was hyperthermic intraperitoneal chemotherapy (HIPEC) with cytoreductive surgery (CRS) for gastric cancer peritoneal metastasis (GCPM); but was associated with an increased morbidity and mortality rate without significantly improving overall survival (OS). While CRS confers limited benefit, the potential role of prophylactic HIPEC and laparoscopic neoadjuvant HIPEC are currently being evaluated. Combination systemic and IP chemotherapy (SIPC) gained popularity in the 1990s, since it provided the benefits of IP treatment while reducing surgical morbidity, demonstrating promising early results in multiple Phase II trials. Unfortunately, these findings were not confirmed in the recent PHOENIX-GC randomized controlled trial; therefore, the appropriate treatment for GCPM remains controversial. Small observational studies from Japan and Singapore have reported successful downstaging of PM in GC patients receiving SIPC who subsequently underwent conversion gastrectomy with a median OS of 21.6–34.6 months. Recently, the most significant development in IP-directed therapy is pressurized IP aerosol chemotherapy (PIPAC). Given that aerosol chemotherapy achieves a wider distribution and deeper penetration, the outcomes of multiple ongoing trials assessing its efficacy are eagerly awaited. Indeed, IP-directed therapy has evolved rapidly in the last 3 decades, with an encouraging trend toward improved outcomes in GCPM, and may offer some hope for an otherwise fatal disease.

Intraperitoneal chemotherapy for peritoneal metastases: an expert opinion

Introduction: The rationale for intraperitoneal (IP) drug delivery for patients with peritoneal metastases (PM) is based on the pharmacokinetic advantage resulting from the peritoneal-plasma barrier, and on the potential to adequately treat small, poorly vascularized PM. Despite a history of more than three decades, many aspects of IP drug delivery remain poorly studied.Areas covered: We outline the anatomy and physiology of the peritoneal cavity, including the pharmacokinetics of IP drug delivery. We discuss transport mechanisms governing tissue penetration of IP chemotherapy, and how these are affected by the biomechanical properties of the tumor stroma. We provide an overview of the current clinical evidence on IP chemotherapy in ovarian, colorectal, and gastric cancer. We discuss the current limitations of IP drug delivery and propose several potential areas of progress.Expert opinion: The potential of IP drug delivery is hampered by off-label use of drugs developed for systemic therapy. The efficacy of IP chemotherapy for PM depends on cancer type, disease extent, and mode of drug delivery. Results from ongoing randomized trials will allow to better delineate the potential of IP chemotherapy. Promising approaches include IP aerosol therapy, prolonged delivery platforms such as gels or biomaterials, and the use of nanomedicine.

Long Noncoding RNA Lnc-TLN2-4:1 Suppresses Gastric Cancer Metastasis and Is Associated with Patient Survival

Gastric cancer (GC) is one of the most common malignancies worldwide, and the tumor metastasis leads to poor outcomes of GC patients. Long noncoding RNAs (lncRNAs) have emerged as new regulatory molecules that play a crucial role in tumor metastasis. However, the biological function and underlying mechanism of numerous lncRNAs in GC metastasis remain largely unclear. Here, we report a novel lncRNA, lnc-TLN2-4:1, whose expression is decreased in GC tissue versus matched normal tissue, and its low expression is involved in the lymph node and distant metastases of GC, as well as poor overall survival rates of GC patients. We further found that lnc-TLN2-4:1 inhibits the ability of GC cells to migrate and invade but does not influence GC cell proliferation and confirmed that lnc-TLN2-4:1 is mainly located in the cytoplasm of GC cells. We then found that lnc-TLN2-4:1 increases the mRNA and protein expression of TLN2 in GC cells and there is a positive correlation between the expression of lnc-TLN2-4:1 and TLN2 mRNA in GC tissue. Collectively, we identified a novel lncRNA, lnc-TLN2-4:1, in GC, where lnc-TLN2-4:1 represses cell migration and invasion. The low expression of lnc-TLN2-4:1 is associated with poor overall survival rates of GC patients. These suggest that lnc-TLN2-4:1 may be a tumor suppressor during GC metastasis.

Evaluation of a Novel Prototype for Pressurized Intraperitoneal Aerosol Chemotherapy

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) has been suggested as an alternative option for treating peritoneal carcinomatosis (PC). Even with its clinical advantages, the current PIPAC system still suffers from limitations regarding drug distribution area and penetration depth. Thus, we evaluated the new PIPAC system using a novel prototype, and compared its performance to the results from previous studies related with the current MIP^® indirectly because the system is currently not available for purchase in the market. The developed prototype includes a syringe pump, a nozzle, and controllers. Drug distribution was conducted using a methylene blue solution for performance test. For penetration depth evaluation, an ex-vivo experiment was performed with porcine tissues in a 3.5 L plastic box. Doxorubicin was sprayed using the novel prototype, and its penetration depth was investigated by confocal laser scanning microscopy. The experiment was repeated with varying nozzle levels from the bottom. The novel prototype sprays approximately 30 μm drug droplets at a flow rate of 30 mL/min with 7 bars of pressure. The average diameter of sprayed region with concentrated dye was 18.5 ± 1.2 cm, which was comparable to that of the current MIP^® (about 10 cm). The depth of concentrated diffusion (DCD) did not differ among varying nozzle levels, whereas the depth of maximal diffusion (DMD) decreased with increasing distance between the prototype and the bottom (mean values, 515.3 μm at 2 cm; 437.6 μm at 4 cm; 363.2 μm at 8 cm), which was comparable to those of the current MIP^® (about 350–500 μm). We developed a novel prototype that generate small droplets for drug aerosolization and that have a comparably wide sprayed area and depth of penetration to the current MIP^® at a lower pressure.