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

Surgical management of gastric adenocarcinoma. Official expert recommendations delivered under the aegis of the French Association of Surgery (AFC)

Gastric adenocarcinoma (GA) is the 5^th most common cancer in the world; in France, however, its incidence has been steadily decreasing. Twenty-five experts brought together under the aegis of the French Association of Surgery collaborated in the drafting of a series of recommendations for surgical management of GA. As concerns preoperative evaluation and work-up, echo-endoscopy aimed at clarifying lymph node status should be performed in all candidates for surgical resection and exploratory laparoscopy in cases of GA cT3/T4 and/or N+ for peritoneal carcinomatosis. On the other hand, PET-scan should not be performed systematically, but only when the other modalities for diagnosis prove insufficient. Laparotomy remains the route of choice to achieve total or partial gastrectomy with D2 lymph node lymphadenectomy for advanced lesions (>T2N0). To limit the risk of dumping syndrome and esophageal reflux and as a way of reestablishing continuity, construction of a jejunal pouch on Roux-en-Y following total gastrectomy is recommended. In cases of peritoneal carcinosis in GA with a low peritoneal cancer index (PCI) (<7) in a patient in good general condition whose disease is controlled by chemotherapy, macroscopically complete cytoreduction with intraperitoneal hyperthermal chemotherapy will probably be required, and it will have to take place in an expert center. Only in the event of Child A cirrhosis may gastrectomy with D2 lymphadenectomy be considered. Palliative gastrectomy or surgical bypass for distal stomach obstruction in a patient in good general condition may also be envisioned.

Non-medical caregivers and the use of intraperitoneal chemotherapy in the operating theatre: A survey on the perception of safety

BACKGROUND

In the last two decades, intraperitoneal(IP) chemotherapy during surgery achieved recognition in the management of peritoneal metastases. Occupational hazard became a concern leading to standardized safety measures. The aim of this study is to evaluate the perceived level of information and protection among the non-medical caregivers involved in HIPEC and PIPAC in a high-volume center.

METHODS

All non-medical caregivers in the operating theatre of our institution were asked to answer a questionnaire between April and May 2018. The questionnaire included multiple choice questions and open questions structured in four parts: demographic variables, perceived level of information, perceived level of protection, interest in further education.

RESULTS

Forty-nine caregivers agreed to answer the questionnaire. All identified IP chemotherapy as an occupational risk. Thirty-eight persons (77.55%) trusted the protective value of safety measures during HIPEC compared to 32 (65.3%) during PIPAC. A total of 29 persons (59.18%) used some of the measures while 16 (32.65%) used all of them. Main reasons of non-use were slips and lapses (7 persons) and lack of comfort (4 persons). A total of 34 caregivers considered the level of information about safety protocols as good or very good (69%). A total of 46 persons considered the level of protection as satisfying or excellent (93.87%). A total of 36 (73.47%) interviewees expressed the need of receiving more information.

CONCLUSIONS

The present study shows that non-medical caregivers in the operating theatres are aware of the occupational hazards related to the use of IP chemotherapy. The use of protective measures is associated with decreased level of perceived risk. However there is a high need of continuous education on this subject for the involved personnel.

Clinical and surgical outcomes of patients with peritoneal mesothelioma discussed at a monthly national multidisciplinary team video-conference meeting

Background

Peritoneal mesothelioma (PM) is a rare primary neoplasm of the peritoneum with an increasing incidence worldwide. Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has shown promise as a treatment strategy. A national PM multidisciplinary team (national PM MDT) video‐conference meeting was established in the UK and Ireland in March 2016, aiming to plan optimal treatment, record outcomes and provide evidence for the benefits of centralization. This article reports on the activities and outcomes of the first 2·5 years.

Methods

Between March 2016 and December 2018, patients with PM, referred to peritoneal malignancy centres in Basingstoke, Birmingham, Manchester and Dublin, were discussed by the national PM MDT via video‐conference. The MDT was composed of surgeons, radiologists, specialist nurses and pathologists. Patients were considered for CRS and HIPEC if considered fit for surgery and if radiological imaging suggested that complete surgical cytoreduction could be achieved. Morbidity and mortality following surgery were analysed. Survival analysis following MDT discussion was conducted.

Results

A total of 155 patients (M : F ratio 0·96) with a mean(s.d.) age of 57(17) years were discussed. To date, 22 (14·2 per cent) have had CRS and HIPEC; the median Peritoneal Cancer Index for the surgical group was 17·0. Complete cytoreduction was achieved in 19 patients. Clavien–Dindo grade I–II complications occurred in 16 patients; there was no grade III–IV morbidity or 30‐day in‐hospital mortality. The median follow‐up for the whole cohort was 18·7 months, and the 2‐year survival rate from time of first review at the national PM MDT was 68·3 per cent.

Conclusion

The centralized national PM MDT was effective at selecting patients suitable for CRS and HIPEC, reporting a good outcome from patient selection.

Targeting the Tumor Microenvironment in Colorectal Peritoneal Metastases

Peritoneal metastasis (PM) occurs in approximately one in four colorectal cancer (CRC) patients. The pathophysiology of colorectal PM remains poorly characterized. Also, the efficacy of current treatment modalities, including surgery and intraperitoneal (IP) delivery of chemotherapy, is limited. Increasingly, therefore, efforts are being developed to unravel the PM cascade and at understanding the PM-associated tumor microenvironment (TME) and peritoneal ecosystem as potential therapeutic targets. Here, we review recent insights in the structure and components of the TME in colorectal PM, and discuss how these may translate into novel therapeutic approaches aimed at re-engineering the metastasis-promoting activity of the stroma.

Intraperitoneal aerosolized drug delivery: Technology, recent developments, and future outlook

Current therapies for patients with peritoneal metastases (PM) are only moderately effective. Recently, a novel locoregional treatment method for PM was introduced, consisting of a combination of laparoscopy with intraperitoneal (IP) delivery of anticancer agents as an aerosol. This 'pressurized intraperitoneal aerosol chemotherapy' (PIPAC) may enhance tissue drug penetration by the elevated IP pressure during CO₂ capnoperitoneum. Also, repeated PIPAC cycles allow to accurately stage peritoneal disease and verify histological response to treatment. This review provides an overview of the rationale, indications, and currently used technology for therapeutic IP nebulization, and discusses the basic mechanisms governing aerosol particle transport and peritoneal deposition. We discuss early clinical results in patients with advanced, irresectable PM and highlight the potential of electrostatic aerosol precipitation. Finally, we discuss promising novel approaches, including nebulization of nanoparticles and prolonged release formulations.

Overcoming Drug Resistance by Taking Advantage of Physical Principles: Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC)

Theoretical considerations as well as comprehensive preclinical and clinical data suggest that optimizing physical parameters of intraperitoneal drug delivery might help to circumvent initial or acquired resistance of peritoneal metastasis (PM) to chemotherapy. Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) is a novel minimally invasive drug delivery system systematically addressing the current limitations of intraperitoneal chemotherapy. The rationale behind PIPAC is: (1) optimizing homogeneity of drug distribution by applying an aerosol rather than a liquid solution; (2) applying increased intraperitoneal hydrostatic pressure to counteract elevated intratumoral interstitial fluid pressure; (3) limiting blood outflow during drug application; (4) steering environmental parameters (temperature, pH, electrostatic charge etc.) in the peritoneal cavity for best tissue target effect. In addition, PIPAC allows repeated application and objective assessment of tumor response by comparing biopsies between chemotherapy cycles. Although incompletely understood, the reasons that allow PIPAC to overcome established chemoresistance are probably linked to local dose intensification. All pharmacological data published so far show a superior therapeutic ratio (tissue concentration/dose applied) of PIPAC vs. systemic administration, of PIPAC vs. intraperitoneal liquid chemotherapy, of PIPAC vs. Hyperthermic Intraperitoneal Chemotherapy (HIPEC) or PIPAC vs. laparoscopic HIPEC. In the initial introduction phase, PIPAC has been used in patients who were quite ill and had already failed multiple treatment regimes, but it may not be limited to that group of patients in the future. Rapid diffusion of PIPAC in clinical practice worldwide supports its potential to become a game changer in the treatment of chemoresistant isolated PM of various origins.

The use of intraperitoneal chemotherapy for gastric malignancies

Introduction: Gastric cancer is the fourth/fifth most common malignancy worldwide, with only a quarter of patients achieving a 5-year survival rate. It has been estimated that 15-50% or more of patients have peritoneal disease upon surgical exploration. Until the early 1990s, peritoneal metastasis was considered as terminal stage of the disease; in the late 1990s, selected patients with peritoneal metastasis were recategorized as local disease. Over the past two decades, the treatment of peritoneal involvement has transformed, and cytoreductive surgery plus intraperitoneal therapy have drastically altered the natural course of several malignancies. Areas covered: We performed a review of studies available on PubMed from 1 January 2014 to 31 July 2019 and the analysis of their reference citations. We describe the most current intraperitoneal chemotherapy opportunities in the treatment of gastric cancer: hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC), laparoscopic hyperthermic intraperitoneal chemotherapy (LHIPEC), neoadjuvant intraperitoneal and systemic chemotherapy (NIPS), LHIPEC + NIPS, extensive intraoperative peritoneal lavage (EIPL), early postoperative intraperitoneal chemotherapy (EPIC), and pressurized intraperitoneal aerosol chemotherapy (PIPAC). Expert opinion: Comprehensive treatment consisting of CRS combined with perioperative intraperitoneal/systemic chemotherapy can, today, be considered an effective strategy to improve the long-term survival of gastric cancer patients with peritoneal metastasis.

A real-time ex vivo model (eIBUB) for optimizing intraperitoneal drug delivery as an alternative to living animal models

BACKGROUND

Optimization of intraperitoneal drug delivery systems requires functional models. We proposed the Inverted Bovine Urinary Bladder Model (IBUB), but IBUB does not allow repeated measurements over time and there is a significant biological variability between organs.

METHODS

A further development of IBUB is presented, based on the physical principle of communicating vessels. Fresh bovine bladders were inverted so that the peritoneum lines up the inner surface. The IBUB and a second vessel were then interconnected under the same CO2 pressure and placed on two scales. The therapeutic solution (Doxorubicin 2.7 mg and Cisplatin 13.5 mg) was delivered via an aerosolizer. All experiments were in triplicate and blinded to the origin of samples, measurements in a GLP-certified laboratory.

RESULTS

The enhanced IBUB (eIBUB) model allows measurements of tissue drug concentration, depth of tissue penetration and spatial distribution. The homogeneous morphology of the peritoneum enables standardized, multiple tissue sampling. eIBUB minimizes biological variability between different bladders and eliminates the bias caused by the liquid collecting at the bottom of the model. Concentration of doxorubicin in the eIBUB (mean ± STDV: 18.5 ± 22.6 ng/mg) were comparable to clinical peritoneal biopsies (19.2 ± 38.6 ng/mg), as was depth of drug penetration (eIBUB: mean (min-max) 433 (381-486) µm, clinical ~ 500 µm).

CONCLUSIONS

The eIBUB model is a simple and powerful ex vivo model for optimizing intraperitoneal drug delivery and represents an attractive alternative to animal models. Results obtained are similar to those obtained in the human patient.

Pressurized IntraPeritoneal Aerosol Chemotherapy with one minute of electrostatic precipitation (ePIPAC) is feasible, but the histological tumor response in peritoneal metastasis is insufficient

INTRODUCTION

Electrostatic precipitation Pressurized IntraPeritoneal Aerosol Chemotherapy (ePIPAC) has shown superior penetration depth and tissue uptake compared to standard PIPAC. We investigated the feasibility and objective tumor response to ePIPAC with 1 min of precipitation in patients with peritoneal metastasis (PM).

MATERIALS AND METHODS

Patients with PM from various abdominal cancers were included in an amendment to the ongoing prospective PIPAC-OPC2 trial. Colorectal and appendiceal PM were treated with oxaliplatin, patients with PM from other primaries were treated with a combination of cisplatin and doxorubicin. Three ePIPAC procedures were planned in each patient including repeated peritoneal biopsies for response evaluation. After emission to the peritoneal cavity, the aerosolized chemotherapeutics were precipitated for 1 min followed by immediate exsufflation and abdominal closure. Histological regression from the first to the third ePIPAC was evaluated according to the Peritoneal Regression Grading Score (PRGS) and compared to data from the PIPAC-OPC1 trial. Complications and toxicities were recorded according to Dindo-Clavien and CTCAE.

RESULTS

Sixty-five ePIPAC procedures were performed in 33 patients (median 2, range 1-6). Ten patients were eligible for response evaluation based on biopsies from the first and third ePIPAC procedure. Four patients had disease progression, four patients had regressive disease, and two patients had stable disease according to PRGS. No life threatening adverse reactions and no mortality was observed following ePIPAC.

CONCLUSION

One minute ePIPAC was feasible and safe, but the histological tumor response was insufficient compared to standard PIPAC directed therapy with 30 min passive diffusion time.

Unresectable peritoneal metastasis treated by pressurized intraperitoneal aerosol chemotherapy (PIPAC) leading to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

BACKGROUND

PIPAC is a recent method of intraperitoneal chemotherapy. The aim of this study was to describe the clinical characteristics of the patients who became amenable to CRS & HIPEC after PIPAC treatment.

METHODS

All patients diagnosed with unresectable PM who became resectable throughout PIPAC treatment were included. Outcome criteria were adverse events following PIPAC procedure and rate of secondary CRS and HIPEC.

RESULTS

Four hundred thirty-seven PIPAC were done in 146 consecutive patients. Among them, 26 patients (17.8%) who underwent 76 PIPAC were scheduled for CRS and HIPEC after reduction of the peritoneal burden. PM were from gastric, peritoneal mesothelioma, ovarian, colorectal and small bowel in 13, 7, 4, 1 and 1 patients, respectively. At the time of the first PIPAC, median age was 58.6 years (32-76.3). Median PCI was 16 (1-39). All patients had systemic chemotherapy in between PIPAC session. Median consecutive PIPAC procedure was 3 (1-8). Complications occurred in 3 PIPAC session (4%) and there was no major complication (CTCAE III or higher). Complete CRS and HIPEC was achieved in 21 patients of the 26 scheduled (14.4%). The remaining 5 patients were considered unresectable at the exploratory laparotomy. Among patients who underwent CRS and HIPEC, with median follow-up of 7 (1-26) months, 14 patients (66.7%) were alive without recurrence, 2 patients (9.5%) were alive with recurrence and 5 patients (23.8%) died.

CONCLUSIONS

Complete CRS and HIPEC can be achieved in strictly selected patient with unresectable PM at diagnosis after repeated PIPAC session with palliative intent.