Pressurized intraperitoneal aerosol chemotherapy (PIPAC) in multimodal therapy for patients with oligometastatic peritoneal gastric cancer: a randomized multicenter phase III trial PIPAC VEROne

Educational Review: Updates on Therapeutic Strategies for Gastric Cancer with Peritoneal Metastasis

Gastric cancer (GC) commonly presents in advanced stages with metastatic spread to the peritoneal cavity, and outcomes associated with gastric cancer with peritoneal metastasis (GCPM) continue to carry a dismal prognosis. Persistent challenges in the detection of peritoneal metastasis (PM) have resulted in a relative paucity of high-quality data to inform management decisions. Several consensus groups have published recommendations to guide management, including most recently the National Comprehensive Cancer Network guidelines, which now include cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) as a potential treatment modality in select patients with GCPM. Multiple clinical trials have investigated the use of CRS/HIPEC and other peritoneal-directed therapies, such as intraperitoneal chemotherapy (IPC) and pressurized intraperitoneal aerosolized chemotherapy (PIPAC). As high-volume centers work to incorporate such therapies into their practice, ongoing clinical trials are aimed at understanding their efficacy. Recent findings have improved understanding of the mechanisms and pathophysiology underlying GCPM while the discovery of novel targets offers potential for drug development and therapeutic strategies to overcome treatment resistance. This review highlights recent advancements and addresses the persistent challenges in managing GCPM while also offering a comprehensive summary of current guidelines and treatment strategies.

Diagnostic Advances and Novel Therapeutics in Peritoneal Metastasis

Appropriate assessment of disease burden in patients with peritoneal surface malignancy (PSM) is critical for treatment decision-making, and conventional cross-sectional imaging (computed tomography and/or MRI) often underestimates burden of disease. Advances in imaging for PSM include novel functional imaging modalities that target cells unique to the tumor microenvironment. Novel alternative methods of diagnosis and disease monitoring are also potentially applicable to management of PSM. These include forms of "liquid biopsy" targeting circulating tumor DNA. Novel regional therapies include both new therapeutic agents (immune-based and nanoparticle-based), as well as new methods of delivery such as pressurized intraperitoneal aerosolized chemotherapy.

Management of peritoneal gastric metastasis: An update

IMPORTANCE

Peritoneal metastases from gastric cancer (PMGC) are associated with poorer median survival and systemic chemotherapy remains the standard of care. This narrative review summarizes the current evidence for medical and surgical treatment of PMGC.

OBSERVATIONS

Treatment is moving to local ways of administering chemotherapy, either intraperitoneal normothermic chemotherapy, laparoscopic hyperthermic intraperitoneal chemotherapy (HIPEC) or even pressurized intraperitoneal aerosol chemotherapy. Furthermore, cytoreductive surgery±HIPEC could also be an alternative in specific situations.

CONCLUSIONS

and relevance: This review provides an updated summary of existing strategies that can be discussed in the management of patients with PMGC.

Iterative Intraperitoneal Chemotherapy in Gastric Cancer Peritoneal Carcinomatosis

Background/objectives: Despite the incremental improvement of survival with systemic therapy in metastatic gastric cancer (GC), the outcomes of patients with peritoneal carcinomatosis (PC) remain poor. The limited effectiveness of systemic therapy is attributed to the blood-peritoneal barrier and anarchic intra-tumoral circulation, which reduce the penetration of systemic therapy. Approaches that incorporate intraperitoneal (IP) chemotherapy, in addition to systemic therapies, may be a viable alternate strategy. Therefore, we provide a review of biology of gastric cancer peritoneal metastasis and evidence for bidirectional iterative IP chemotherapy in GCPC. Methods: A comprehensive search in PubMed, Scopus, Embase, Web of Science, Google Scholar, and ClinicalTrials.gov was performed to find the relevant articles and ongoing phase II/III clinical trials in iterative IP chemotherapy in GCPC. Results: Intraperitoneal (IP) chemotherapy leverages the blood-peritoneal barrier to allow for the administration of high concentrations of chemotherapy directly to the peritoneal metastases, with a significant reduction in the systemic toxicity and enhanced drug efficacy against peritoneal metastasis. This pharmacokinetic advantage of IP chemotherapy can be further enhanced by additional measures such as heat or aerosolization. There are three IP chemotherapy approaches, namely, heated intraperitoneal chemotherapy (HIPEC), pressurized intraperitoneal aerosolized chemotherapy (PIPAC), and normothermic intraperitoneal chemotherapy (NIPEC). Recent evidence suggests that iterative IP chemotherapy combined with systemic therapy may offer significant survival benefits for patients with peritoneal metastasis. Furthermore, bidirectional treatment approaches may also increase the chances of surgical resection and survival. Conclusions: IP chemotherapy plays a pivotal role in the management of gastric carcinomatosis, particularly in combination with cytoreduction in highly selected patients. The combination of systemic and regional control may increase the chances of surgical resection and may ultimately lead to significant survival benefits.

Predictive Factors for the Discontinuation of Pressurized Intraperitoneal Aerosol Chemotherapy: Enhancing Patient Selection to Improve Oncological Outcomes-A Single-Center Experience

Background: Since 2011, Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) has emerged as a promising treatment option for patients with peritoneal surface malignancies (PSM) who are not eligible for cytoreductive surgery (CRS). Repeated minimal-invasive treatment is one of the key features and the current empirical standard treatment (ST) consists of at least three administrations over about three months. However, many patients are unable to complete the full course, limiting the potential benefits of PIPAC. Method: This retrospective, single-center study assessed the completion rate of ST and identified the main causes and predictive factors for discontinuation. This study also evaluated the feasibility, safety, and efficacy of PIPAC and investigated whether improved patient selection over the years has resulted in better oncological outcomes. Result: Data from 168 patients treated with PIPAC between January 2017 and March 2023 for a total of 336 procedures showed that only 29% completed ST. Multivariate analysis identified ascites >500 mL and a prior history of bowel obstruction as significant predictors of discontinuation. Conclusions: Patients with radiological or clinical signs of obstruction should not be considered for PIPAC treatment, and ascites increases the risk of incomplete treatment. Larger studies are eagerly awaited to corroborate these findings and refine the selection criteria by disease entity.

Efficacy and Insights from an Extensive Series of Cytoreductive Surgery for Peritoneal Neoplasms: A High-Volume Single-Center Experience

Background: Advances in cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) and pressurized intraperitoneal aerosol chemotherapy (PIPAC) have improved outcomes for selected patients with peritoneal surface malignancies (PSMs). Methods: This retrospective study analyzed 743 PSM patients treated at Fondazione Policlinico Universitario Agostino Gemelli from January 2016 to February 2024. The primary aim was to assess median overall survival (mOS), median disease-free survival (mDFS), and median progression-free survival (mPFS) stratified by tumor origin. Secondary outcomes examined the role of diagnostic laparoscopy in the management of PSMs and intra- and postoperative complications' rates. Results: A total of 1113 procedures were performed: 389 CRS, 370 PIPAC, and 354 diagnostic laparoscopies. Colorectal cancer was the predominant indication for CRS (52.4%), with a mOS of 52 months and mDFS of 22 months. Patients affected by gastric cancer undergoing CRS had a mOS of 18 months and a mDFS of 13 months, while PIPAC yielded a mOS of 9 months and a mPFS of 4 months. Among patients with pseudomyxoma peritonei undergoing CRS, the 5-year DFS rate was 64.1%, and OS rate was 89%. Patients affected by mesothelioma and treated with CRS exhibited a median OS of 43 months and a DFS of 26 months. Pancreatic and hepatobiliary cancers were treated with PIPAC, with a respective mOS of 12 and 8 months. Postoperative complications occurred in 12.6% of CRS, 3.2% of PIPAC, and 1.7% of diagnostic laparoscopies. High peritoneal cancer index (PCI), gastric resection, and blood loss over 500 mL were identified as risk factors for major complications in a multivariate analysis. Conclusions: Developing a highly experienced multidisciplinary team is crucial for delivering tailored treatment strategies which aim to achieve optimal oncological outcomes while preserving patients' quality of life.

Emerging Treatment Modalities for Gastric Cancer With Macroscopic Peritoneal Metastases: A Systematic Review

Gastric cancer with macroscopic peritoneal metastases represents a major therapeutic challenge and is associated with a poor prognosis. This review aims to evaluate the efficacy and safety of new treatment modalities. A systematic search of PubMed was conducted to identify studies published between January 2014 and April 2024. Inclusion criteria were trials investigating novel therapies for gastric cancer with peritoneal metastases. Data on treatment efficacy, survival outcomes, and side effects were extracted.

Oligometastatic esophageal cancer cured by systemic therapy combined with radiotherapy to primary tumor and metastasis (metastasis-directed therapy)-small case series

The prognosis of metastatic esophageal cancer (EC) remains poor with an average life expectancy of around 9-12 months with standard systemic chemotherapy. The concept of oligometastatic disease (OMD) in EC cancer is controversial with no universally accepted definition. From the original cohort of metastatic oesophago-gastric (OG) cancer patients, 4 cases were identified that developed unusually favourable outcome with long-term survival and probable cure. In retrospect, all patients had OMD at presentation with striking similarities in terms of their clinical presentation, staging, treatment response and outcomes. All patients presented with locally advanced EC and 1-2 areas of metastatic disease (bone, lung, non-regional lymph node (LN) involvement). All were treated with combined therapeutic strategy using initial systemic chemotherapy followed by local radiotherapy to primary tumor and adjacent areas of visible/residual metastatic disease (metastasis-directed therapy). All patients experienced long-term survival (range = 7-13 years) with no evidence of recurrence and probable cure. The present case series adds to the growing pool of evidence indicating OM EC cancer represents a distinct and prognostically favorable subgroup.

Efficacy of Hyperthermic Pressurized Intraperitoneal Aerosol Chemotherapy in an In Vitro Model Using a Human Gastric Cancer AGS Cell Line and an Abdominal Cavity Model

PURPOSE

Peritoneal carcinomatosis (PC) presents a major challenge in the treatment of late-stage, solid tumors, with traditional therapies limited by poor drug penetration. We evaluated a novel hyperthermic pressurized intraperitoneal aerosol chemotherapy (HPIPAC) system using a human abdominal cavity model for its efficacy against AGS gastric cancer cells.

MATERIALS AND METHODS

A model simulating the human abdominal cavity and AGS gastric cancer cell line cultured dishes were used to assess the efficacy of the HPIPAC system. Cell viability was measured to evaluate the impact of HPIPAC under 6 different conditions: heat alone, PIPAC with paclitaxel (PTX), PTX alone, normal saline (NS) alone, heat with NS, and HPIPAC with PTX.

RESULTS

Results showed a significant reduction in cell viability with HPIPAC combined with PTX, indicating enhanced cytotoxic effects. Immediately after treatment, the average cell viability was 66.6%, which decreased to 49.2% after 48 hours and to a further 19.6% after 120 hours of incubation, demonstrating the sustained efficacy of the treatment. In contrast, control groups exhibited a recovery in cell viability; heat alone showed cell viability increasing from 90.8% to 94.4%, PIPAC with PTX from 82.7% to 89.7%, PTX only from 73.3% to 74.8%, NS only from 90.9% to 98.3%, and heat with NS from 74.4% to 84.7%.

CONCLUSIONS

The HPIPAC system with PTX exhibits a promising approach in the treatment of PC in gastric cancer, significantly reducing cell viability. Despite certain limitations, this study highlights the system's potential to enhance treatment outcomes. Future efforts should focus on refining HPIPAC and validating its effectiveness in clinical settings.

Staging laparoscopy with peritoneal lavage to identify peritoneal metastases and free intraperitoneal cancer cells in the management of locally advanced gastric cancer

INTRODUCTION

Gastric cancer often presents in advanced stage with a significant risk for peritoneal dissemination. Staging laparoscopy can be used to detect peritoneal carcinomatosis (PC+) and free cancer cells in peritoneal lavage cytology (CY+). The current study aimed to present the outcomes of staging laparoscopy and the prognosis of PC+ and CY+ in a Swedish high-volume center.

MATERIALS AND METHODS

A cohort study including all consecutive patients with locally advanced gastric cancer who underwent staging laparoscopy between February 2008 and October 2022. The laparoscopy findings were categorized as PC+, PC-CY+ (positive cytology without peritoneal carcinomatosis) or negative laparoscopy (PC-CY-). The primary endpoint was overall survival (OS) stratified by laparoscopy findings. The secondary endpoint was OS within each laparoscopy finding group stratified by subsequent treatment.

RESULTS

Among 168 patients who underwent staging laparoscopy, 78 patients (46%) had PC-CY-, 29 patients (17%) had PC-CY+ and 61 patients (36%) had PC+. Decreased OS was observed for both PC-CY+ patients (aHR 2.14, 95% CI 1.13-4.06) and PC+ patients (aHR 5.36, 95% CI 3.21-8.93), compared to PC-CY-. Patients with PC-CY+ who converted to PC-CY- after chemotherapy and underwent tumor resection seemed to have a better prognosis compared to patients with persisting PC-CY+.

CONCLUSIONS

Staging laparoscopy is an important tool in the staging of locally advanced gastric cancer. Tumor resection for patients with PC-CY+ who convert to PC-CY- may lead to improved survival for these patients.

RNA expression profiling of peritoneal metastasis from pancreatic cancer treated with Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC)

Objectives

Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) is an experimental treatment option in peritoneal metastasis from pancreatic cancer (PM-PC). Aims were to examine mRNA profile of fibrosis due to response after systemic chemotherapy and PIPAC (Regression) compared to treatment-naïve PM-PC and chronic cholecystitis-related peritoneal fibrosis (Controls).

Methods

Peritoneal biopsies (PBs) from PM-PC patients who had undergone systemic chemotherapy and PIPAC were evaluated with Peritoneal Regression Grading Score (PRGS). We extracted RNA from PBs with Regression (PRGS 1, n=11), treatment-naïve PM-PC (n=10), and Controls (n=10). Profiling of 800 mRNAs was performed (NanoString nCounter, PanCancer Immuno-Oncology 360 (IO-360) and 30 additional stroma-related mRNAs).

Results

Regression vs. PM-PC identified six up-regulated and 197 down-regulated mRNAs (FDR≤0.05), linked to TNF-α signaling via NF-kB, G2M checkpoint, epithelial-mesenchymal transition, estrogen response, and coagulation. Regression vs. Controls identified 43 significantly up-regulated mRNAs, linked to interferon-α response, and down-regulation of 99 mRNAs, linked to TNF-α signaling via NF-kB, inflammatory response, epithelial-mesenchymal transition, KRAS signaling, and hypoxia (FDR≤0.05).

Conclusions

In regressive fibrosis of PM-PC after systemic chemotherapy and PIPAC (Regression), downregulation of mRNAs related to key tumor biological pathways was identified. Regression also showed transcriptional differences from unspecific, benign fibrosis (Controls). Future studies should explore whether mRNA profiling of PBs with PM from PC or other primaries holds prognostic or predictive value.

Regional Therapy Approaches for Gastric Cancer with Limited Peritoneal Disease

PURPOSE

Despite advances in systemic therapy, outcomes of patients with gastric cancer (GC) peritoneal carcinomatosis (PC) remain poor, in part because of poor penetrance of systemic therapy into peritoneal metastasis due to the plasma-peritoneal barrier and anarchic intra-tumoral circulation. Hence, regional treatment approach with administration of chemotherapy directly into the peritoneal cavity (intraperitoneal, IP) under various conditions, combined with or without cytoreductive surgery (CRS) has remained an area of significant research interest. The purpose of this review is to provide high-level evidence for regional treatment approaches in the management of GCPC with limited peritoneal disease.

METHODS

A review of the current literature and ongoing clinical trials for regional IP therapies for GCPC was performed. Studies included in this review comprise of phase III randomized controlled trials, non-randomized phase II studies, high-impact retrospective studies, and active ongoing clinical trials for each available IP modality.

RESULTS

The three common IP approaches are heated intraperitoneal chemotherapy (HIPEC), normothermic intraperitoneal chemotherapy (NIPEC) and more recently introduced, pressurized intraperitoneal aerosolized chemotherapy (PIPAC). These IP approaches have been combined with systemic therapy and/or CRS with varying degrees of promising results, demonstrating evidence of improvements in survival rates and peritoneal disease control. Patient selection, optimization of systemic therapy, and completeness of cytoreduction have emerged as major factors influencing the design of contemporary and ongoing trials.

CONCLUSION

IP chemotherapy has a clear role in the management of patients with GCPC, and when combined with CRS in appropriately selected patients has the potential to significantly improve survival. Ongoing and upcoming IP therapy clinical trials hold great promise to shape the treatment paradigm for GCPC.

Advances in Gastric Cancer Surgical Management

The goal of a gastric cancer operation is a microscopically negative resection margin and D2 lymphadenectomy. Minimally invasive techniques (laparoscopic and robotic) have been proven to be equivalent for oncologic care, yet with faster recovery. Endoscopic mucosal resection can be used for T1a N0 tumor resection. Better understanding of hereditary gastric cancer and molecular subtypes has led to specialized recommendations for MSI-high tumors and patients with pathogenic CDH1 mutations. In the future, surgical management will support minimally invasive approaches and personalized cancer care based on subtype.

Performance of different nebulizers in clinical use for Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC)

OBJECTIVE

Technical ex-vivo comparison of commercial nebulizer nozzles used for Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC).

METHODS

The performance of four different commercial nebulizer nozzles (Nebulizer; HurriChemTM; MCR-4 TOPOL®; QuattroJet) was analysed concerning: i) technical design and principle of operation, ii) operational pressure as function of the liquid flow rate, iii) droplet size distribution via laser diffraction spectrometry, iv) spray cone angle, spray cone form as well as horizontal drug deposition by image-metric analyses and v) chemical resistance via exposing to a cytostatic solution and chemical composition by means of spark optical emission spectral analysis.

RESULTS

The Nebulizer shows quasi an identical technical design and thus also a similar performance (e.g., mass median droplet size of 29 μm) as the original PIPAC nozzles (MIP/ CapnoPen). All other nozzles show more or less a performance deviation to the original PIPAC nozzles. The HurriChemTM has a similar design and principle of operation as the Nebulizer, but provides a finer aerosol (22 μm). The principle of operation of MCR-4 TOPOL® and QuattroJet differ significantly from that of the original PIPAC nozzle technology. The MCR-4 TOPOL® offers a hollow spray cone with significantly larger droplets (50 μm) than the original PIPAC nozzles. The QuattroJet generates an aerosol (22 μm) similar to that of the HurriChemTM but with improved spatial drug distribution.

CONCLUSION

The availability of new PIPAC nozzles is encouraging but can also have a negative impact if their performance and efficacy is unknown. It is recommended that PIPAC nozzles that deviate from the current standard should be subject to bioequivalence testing and implementation in accordance with the IDEAL-D framework prior to routine clinical use.

Hyperthermic pressurized intraperitoneal aerosol drug delivery system in a large animal model: a feasibility and safety study

BACKGROUND

We developed a novel drug delivery system called hyperthermic pressurized intraperitoneal aerosol chemotherapy (HPIPAC) that hybridized Hyperthermic intraperitoneal chemotherapy (HIPEC) and pressurized intraperitoneal aerosol chemotherapy (PIPAC). The present study aims to assess the feasibility and safety of HPIPAC system in a large animal survival model.

METHODS

Eleven pigs (eight non-survival models and three survival models) were used in the experiment. The heat module in the HPIPAC controller circulates hyperthermic CO2 in a closed-loop circuit and creates gas-based dry intraperitoneal hyperthermia. Three 12 mm trocars were placed on the abdomen. The afferent CO2 tube wound with heat generating coil was inserted into a trocar, and the efferent tube was inserted into another trocar. Heated CO2 was insufflated and circulated in a closed circuit until the intra-abdominal and peritoneal surface temperature reached 42 °C. 100 ml of 5% dextrose in water was nebulized for 5 min and the closed-loop circulation was resumed for 60 min at 42 °C. Tissue biopsies were taken from several sites from the pigs in the survival model.

RESULTS

The average change in core temperature of the pigs was 2.5 ± 0.08 °C. All three pigs displayed no signs of distress, and their vital signs remained stable, with no changes in their diet. In autopsy, inflammatory and fibrotic responses at the biopsy sites were observed without serious pathologic findings.

CONCLUSIONS

We successfully proved the feasibility and safety of our novel HPIPAC system in an in-vivo swine survival model.

Peritoneal Metastatic Gastric Cancer: Local Treatment Options and Recommendations

Peritoneal metastasis is a common finding in patients with advanced gastric cancer. Beyond systemic chemotherapy, additive local treatments such as cytoreductive surgery and intraperitoneal chemotherapy are considered an inherent part of different multimodal treatment concepts for selected patients with peritoneal metastatic gastric cancer. This review article discusses the role of cytoreductive surgery (CRS) and intraperitoneal chemotherapy, including HIPEC, NIPS, and PIPAC, as additive therapeutic options with curative and palliative intent.

Gastric cancer with peritoneal metastases: a single center outline and comparison of different surgical and intraperitoneal treatments

INTRODUCTION

Gastric cancer with peritoneal metastasis (GCPM) has an unfavourable prognosis. Cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) and pressurized intraperitoneal aerosol chemotherapy (PIPAC) are promising treatment options that have been shown to improve survival. The aim of this study was to assess the impact of different treatments such as systemic chemotherapy, systemic chemotherapy + PIPAC, and CRS + HIPEC in patients with GCPM.

MATERIAL AND METHODS

This single-centre retrospective study included 82 patients with GCPM treated between January 2016 and June 2021. After first-line chemotherapy, depending on disease response and burden, the patients were divided into three treatment groups: chemotherapy alone, chemotherapy + PIPAC, and CRS + HIPEC. The primary outcome was overall survival (OS) from diagnosis, which was compared among the treatment groups.

RESULTS

Thirty-seven (45.1%) patients were administered systemic chemotherapy alone, 25 (30.4%) received chemotherapy + PIPAC, and 20 (24.4%) underwent CRS + HIPEC. The CRS + HIPEC group had better OS (median 24 months) than the PIPAC group (15 months, p = 0.01) and chemotherapy group (5 months, p = 0.0001). Following CRS + HIPEC, the postoperative grade 3-4 complication rate was 25%, and no postoperative in-hospital deaths occurred. The median disease-free survival (DFS) was 12 months. Multivariate analysis identified peritoneal carcinomatosis index (PCI) > 7 as an independent predictor of worse DFS. No independent predictors of OS were identified.

CONCLUSION

Among patients with GCPM, we identified a highly selected population with oligometastatic disease. In this group, CRS + HIPEC provided a significant survival advantage with an acceptable major complication rate compared with other available therapies (systemic chemotherapy alone or in combination with PIPAC).

Bidirectional Approach with PIPAC and Systemic Chemotherapy for Patients with Synchronous Gastric Cancer Peritoneal Metastases (GCPM)

BACKGROUND

This study evaluated the efficacy of pressurized intraperitoneal aerosol chemotherapy (PIPAC) with systemic chemotherapy as a bidirectional approach for gastric cancer (GC) patients with synchronous peritoneal metastases (SPM).

METHODS

A retrospective analysis of a prospective PIPAC database was queried for patients who underwent a bidirectional approach between October 2019 and April 2022 at two high-volume GC surgery units in Italy (Verona and Siena). Surgical and oncological outcomes were analyzed.

RESULTS

Between October 2019 and April 2022, 74 PIPAC procedures in 42 consecutive patients with Eastern Cooperative Oncology Group performance status ≤2 were performed-32 patients treated in Verona and 10 in Siena. Twenty-seven patients (64%) were female and median age at first PIPAC was 60.5 years (I-III quartiles: 49-68 years). Median Peritoneal Cancer Index (PCI) was 16 (I-III quartiles: 8-26) and 25 patients (59%) had at least two PIPAC procedures. Major complications according to the Common Terminology Criteria for Adverse Events (CTCAE; 3 and 4) occurred in three (4%) procedures, and, according to the Clavien-Dindo classification (>3a), one (1%) severe complication occurred. There were no reoperations or deaths within 30 days. Median overall survival (mOS) from diagnosis was 19.6 months (range 14-24), and mOS from first PIPAC was 10.5 months (range 7-13). Excluding cases with very heavy metastatic peritoneal burden, with PCI from 2 to 26, treated with more than one PIPAC, mOS from diagnosis was 22 months (range 14-39). Eleven patients (26%) underwent curative-intent surgery after a bidirectional approach. R0 was achieved in nine (82%) patients and complete pathological response was obtained in three (27%) cases.

CONCLUSIONS

Patient selection is associated with bidirectional approach efficacy and feasibility for SPM GC treatment, which may allow potentially curative surgical radicalization in highly selected cases.

Gastric Cancer (GC) with Peritoneal Metastases (PMs): An Overview of Italian PSM Oncoteam Evidence and Study Purposes

Gastric cancer (GC) continues to be one of the leading types of malignancies worldwide, despite an ongoing decrease in incidence. It is the fifth most frequent type of cancer in the world and the fourth leading cause of cancer death. Peritoneal metastases (PMs) occur in 20-30% of cases during the natural history of the disease. Systemic chemotherapy (SC) is undoubtedly the standard of care for patients with GC and PMs. However, with the development of highly effective regimens (SC combined with intraperitoneal chemotherapy), significant tumor shrinkage has been observed in many patients with synchronous GC and PMs, allowing some to undergo curative resection "conversion surgery" with long-term survival. In recent years, there has been growing interest in intraperitoneal chemotherapy for PMs, because the reduced drug clearance associated with the peritoneal/plasma barrier allows for direct and prolonged drug exposure with less systemic toxicity. These procedures, along with other methods used for peritoneal surface malignancies (PSMs), can be used in GCs with PMs as neoadjuvant chemotherapy or adjuvant treatments after radical surgery or as palliative treatments delivered either laparoscopically or-more recently-as pressurized intraperitoneal aerosol chemotherapy. The great heterogeneity of patients with stage IV gastric cancer did not allow us to carry out a systemic review; therefore, we limited ourselves to providing readers with an overview to clarify the indications and outcomes of integrated treatments for GCs with PMs by analyzing reports from the international clinical literature and the specific experiences of our oncoteam.

Safety and Efficacy of Simultaneous Resection of Gastric Carcinoma and Synchronous Liver Metastasis-A Western Center Experience

Background and objectives: Gastric cancer (GC) is often diagnosed in the metastatic stage. Palliative systemic therapy is still considered the gold standard, even for patients with resectable oligometastatic disease. The aim of the current study is to assess the potential benefit of up-front gastric and liver resection in patients with synchronous resectable liver-only metastases from GC (LMGC) in a Western population. Materials and Methods: All patients with GC and synchronous LMGC who underwent gastric resection with or without simultaneous resection of LMs between January 1997 and December 2016 were selected from the institutional records. Those with T4b primary tumors or with unresectable or more than three LMs were excluded from the analysis. All patients who underwent emergency surgery for hemorrhagic shock or gastric perforation were also excluded. Results: Out of 28 patients fulfilling the inclusion criteria, 16 underwent simultaneous gastric and liver resection (SR group), while 12 underwent palliative gastric resection (GR group). The median overall survival (OS) of the entire cohort was of 18.81 months, with 1-, 3- and 5-year OS rates of 71.4%, 17.9% and 14.3%, respectively. The 1-, 3- and 5-year OS rates in SR group (75%, 31.3% and 25%, respectively) were significantly higher than those achieved in GR group (66.7%, 0% and 0%, respectively; p = 0.004). Multivariate analysis of the entire cohort revealed that the only independent prognostic factor associated with better OS was liver resection (HR = 3.954, 95% CI: 1.542-10.139; p = 0.004). Conclusions: In a Western cohort, simultaneous resection of GC and LMGC significantly improved OS compared to patients who underwent palliative gastric resection.