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

Primary and metastatic peritoneal surface malignancies

Peritoneal surface malignancies comprise a heterogeneous group of primary tumours, including peritoneal mesothelioma, and peritoneal metastases of other tumours, including ovarian, gastric, colorectal, appendicular or pancreatic cancers. The pathophysiology of peritoneal malignancy is complex and not fully understood. The two main hypotheses are the transformation of mesothelial cells (peritoneal primary tumour) and shedding of cells from a primary tumour with implantation of cells in the peritoneal cavity (peritoneal metastasis). Diagnosis is challenging and often requires modern imaging and interventional techniques, including surgical exploration. In the past decade, new treatments and multimodal strategies helped to improve patient survival and quality of life and the premise that peritoneal malignancies are fatal diseases has been dismissed as management strategies, including complete cytoreductive surgery embedded in perioperative systemic chemotherapy, can provide cure in selected patients. Furthermore, intraperitoneal chemotherapy has become an important part of combination treatments. Improving locoregional treatment delivery to enhance penetration to tumour nodules and reduce systemic uptake is one of the most active research areas. The current main challenges involve not only offering the best treatment option and developing intraperitoneal therapies that are equivalent to current systemic therapies but also defining the optimal treatment sequence according to primary tumour, disease extent and patient preferences. New imaging modalities, less invasive surgery, nanomedicines and targeted therapies are the basis for a new era of intraperitoneal therapy and are beginning to show encouraging outcomes.

Regional therapy trials in peritoneal metastases: The path to standardization of care for gastric cancer

As the peritoneum is the most common site of metastatic disease at diagnosis, disease identified at staging laparoscopy, and site of recurrence for patients with gastric cancer, intraperitoneal therapy has been an area of interest for many investigators. There are several ways to categorize the existing trials and studies. One is by indication, which includes palliative, neoadjuvant, adjuvant, and prophylactic. Another is by treatment modality which includes approaches such as hyperthermic intraperitoneal chemotherapy, pressurized intraperitoneal aerosol chemotherapy, intraperitoneal normothermic chemotherapy, and bidirectional combinations of systemic and intraperitoneal therapy. Recently completed and ongoing trials of peritoneal therapy in gastric cancer may be improving on the historically dismal survival rates for patients with carcinomatosis or disease at high risk of peritoneal recurrence. All completed randomized trials are from outside the United States, and additional studies of peritoneal therapy in Western populations are needed to clarify survival outcomes. Cooperative group trials and multi-institutional registry study efforts are ongoing to help address this clear area of unmet need.

Non-resectable Malignant Peritoneal Mesothelioma Treated with Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) Plus Systemic Chemotherapy Could Lead to Secondary Complete Cytoreductive Surgery: A Cohort Study

BACKGROUND

Diffuse malignant peritoneal mesothelioma (DMPM) is an aggressive primary peritoneal neoplasia. At diagnosis, few patients are eligible for a recommended cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Among neoadjuvant strategies, pressurized intraperitoneal aerosol chemotherapy (PIPAC) combined with systemic chemotherapy has been recently proposed. This study evaluated this strategy in a cohort of DMPM patients.

METHODS

Patients with DMPM and primary or recurrent non-resectable diseases who received at least one PIPAC procedure in alternation with systemic chemotherapy were included in this retrospective study to analyze oncologic outcomes.

RESULTS

Overall, 26 DMPM patients were treated with at least one PIPAC, including 20 patients with no previous CRS. Of 22 patients (85%) who had symptoms, 9 had perceptible ascites. Overall, 79 PIPAC procedures were performed, with half of the patients receiving three PIPAC procedures or more. Among eight patients (31%), 10 adverse events (13% of procedures) were reported, including two severe complications, both corresponding to digestive perforations. Improvement of symptoms was reported for 32% of the patients, whereas control of ascites was noted in 46%. All but one procedure among 14 patients (54%) secondarily treated by CRS-HIPEC were considered complete resections. After a median follow-up period of 29.6 months (95% confidence interval [CI], 17.6-not reached [NR]), the median overall survival period was 12 months (95% CI 11.1-NR). The median progression-free survival (PFS) was significantly better among the patients who underwent resection than among those who did not (33.5 vs 7.4 months; hazard ratio [HR], 0.18; 95% CI 0.06-0.755; p < 0.001).

CONCLUSIONS

For patients with initially non-resectable DMPM, PIPAC is feasible for treatment with neoadjuvant intent and could facilitate complete secondary resection.

The Burden of Peritoneal Metastases from Gastric Cancer: A Systematic Review on the Incidence, Risk Factors and Survival

The peritoneum is a common metastatic site in gastric cancer. This systematic review provides an overview of the incidence, risk factors and survival of synchronous peritoneal metastases from gastric cancer. A systematic search was performed to identify studies wherein the incidence, risk factors and survival of gastric cancer with peritoneal metastases were investigated. Of all 38 potentially eligible studies, 17 studies were included based on the eligibility criteria. The incidence of synchronous gastric peritoneal metastases was reviewed for population-based studies (10-21%), for observational cohort studies (2-15%) and for surgical cohort studies (13-40%). Potential risk factors for synchronous gastric peritoneal metastases were younger age, non-cardia gastric cancer, female sex, signet ring cell carcinoma, diffuse type histology or linitis plastica, T4 stage, Hispanic ethnicity and more than one metastatic location. Synchronous peritoneal metastases are commonly diagnosed in patients with gastric cancer with an incidence up to 21% in recent population-based studies. Furthermore, prognosis of patients with gastric peritoneal metastases is poor with median overall survival ranging from 2 to 9 months. The high incidence and poor prognosis require intensive research on diagnostic features and effective treatment options to improve survival.

Effect of Pressurized Intraperitoneal Aerosol Chemotherapy on the Survival Rate of Patients with Peritoneal Carcinomatosis of Gastric Origin

INTRODUCTION

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new surgical technique for the treatment of initially unresectable peritoneal carcinomatosis (PC). Our objective was to compare the results of PIPAC associated with systemic chemotherapy (PIPAC_CHEM) with those of systemic chemotherapy alone (ONLY_CHEM) in patients with gastric PC without metastasis other than peritoneal, and the WHO performance status < 3.

METHODS

This was a retrospective, single center, comparative non-randomized study. Seventeen PIPAC_CHEM patients were compared to 29 ONLY_CHEM patients. The primary endpoint was overall survival at 6 months from diagnosis of PC.

RESULTS

Ninety-eight patients were screened and 46 were included (PIPAC_CHEM, n = 17; ONLY_CHEM, n = 29). The PIPAC_ CHEM population was significantly younger (median 64 years [56; 68] vs 74 years [61; 79]; p = 0.0054). Median PIPAC session per patient is 2 [1-3]. Six-month survival was significantly higher in the PIPAC_CHEM group than in the ONLY_CHEM group 16/17 (94.1% [65-99.2]) vs 19/29 (65.5% [45.4-79.7]), respectively; p = 0.029. Over the entire follow-up, median survival [95% CI] was 12.8 months [7.2-34.3] with PIPAC vs 9.1 months [5.4-11.5] without, p = 0.056. At 6 months, median length of additional hospitalization was significantly less for PIPAC_CHEM (median 2 days [2-7]) than without PIPAC (median 11 days [3-21]) (p = 0.045).

CONCLUSION

The overall survival at 6 months after the diagnosis of carcinomatosis was significantly better for PIPAC_CHEM patients. This difference appears to continue until at least 18 months. At 6 months, days of additional hospitalization was significantly less in the PIPAC_CHEM group.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT 04,879,953.

Clinical Outcome for Patients Managed with Low-Dose Cisplatin and Doxorubicin Delivered as Pressurized Intraperitoneal Aerosol Chemotherapy for Unresectable Peritoneal Metastases of Gastric Cancer

BACKGROUND

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is increasingly used to manage gastric cancer peritoneal metastasis (GCPM).

METHODS

This study analyzed a prospective database of GCPM patients treated with cisplatin and doxorubicin PIPAC (PIPAC-C/D). The outcome criteria were adverse events, pathologic response [peritoneal regression grading score (PRGS)], and overall survival (OS).

RESULTS

The PIPAC-C/D procedure was scheduled for 144 patients with a median age of 57 years (range 22-88 years). Access to the abdominal cavity for the first PIPAC failed in 11 patients (7.7 %). A total of 296 procedures were performed for 131 patients. Of the 144 patients, 52 (36.1%) underwent one PIPAC, 32 (22.2%) underwent two PIPACs, 24 (16.7%) underwent three PIPACs, and 21 (14.6%) underwent four or more PIPACs. The overall morbidity/mortality was grade 1 for 22 patients (15.3%), grade 2 for 32 patients (22.2%), grade 3 for 7 patients (4.9%), grade 4 for no patients (0%), and grade 5 for 2 patients (1.4%). Of the 37 patients who had three or more PIPACs eligible for histopathologic response analysis, 27 (73%) had major or complete regression (PRGS 1/2). A median OS of 11 months (range 0-61 months) for the total study population and 16 months (range 2-61 months) for the patients with three or more PIPACs was observed. For 10 patients (7%) who underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, the median OS was 15 months (minimum, 4 months; maximum, 27 months). Multivariate analysis showed three or more PIPACs to be an independent prognostic factor for improved OS (hazard ratio, 0.36; p < 0.0001).

CONCLUSIONS

Repetitive PIPAC-C/D ± systemic chemotherapy is associated with low morbidity and mortality rates. Prospective randomized trials are needed to confirm whether three or more PIPAC-C/Ds improve clinical outcome.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) for peritoneal malignancy: initial experience of the first program in the Baltic countries

BACKGROUND

Peritoneal malignancies include primary and metastatic cancer of the peritoneal cavity. The most common origin for peritoneal metastasis is ovarian, gastric, and colorectal cancers. Irrespective of the origin, peritoneal metastases represent the advanced disease and are associated with poor long-term outcomes. The minimally invasive approach of pressurized intraperitoneal aerosol chemotherapy (PIPAC) allows repeated applications and objective assessment of tumor response by comparing histological samples. This study aimed to investigate the initial experience with PIPAC in the Baltic region.

METHODS

All patients who underwent PIPAC at Vilnius University Hospital Santaros Klinikos between 2015 and 2020 were included in this retrospective study. The primary outcome of the study was overall survival (OS) in patients with peritoneal carcinomatosis treated by PIPAC. The secondary outcomes included postoperative morbidity; peritoneal carcinomatosis index (PCI) and ascites reduction after treatment by PIPAC.

RESULTS

In total, 15 patients underwent 34 PIPAC procedures. PIPAC-related intraoperative and postoperative morbidity occurred in 3 (8.8%) of 34 procedures. Following PIPAC, the median PCI decreased from 8 (4; 15) to 5 (1; 16) in GC patients, although, the difference failed for significance, p = 0.581. In OC patients, PCI after PIPAC remained stable. Median overall survival after PIPAC procedure was 25 (95% CI 5-44) months. Ovarian cancer patients (22; 95% CI 12-44 months) had significantly higher OS, compared to gastric cancer patients (8; 95% CI 4-16 months), p = 0.018.

CONCLUSIONS

PIPAC is safe and feasible for patients with gastric and ovarian cancers peritoneal metastases.

Development of rotational intraperitoneal pressurized aerosol chemotherapy to enhance drug delivery into the peritoneum

This study aims to evaluate the drug distribution, tissue concentrations, penetration depth, pharmacokinetic properties, and toxicities after rotational intraperitoneal pressurized aerosol chemotherapy (RIPAC) in pigs. Because relevant medical devices have not been introduced, we developed our prototype of pressurized intraperitoneal aerosol chemotherapy (PIPAC) and RIPAC by adding a conical pendulum motion device for rotating the nozzle. RIPAC and PIPAC were conducted using 150 ml of 1% methylene blue to evaluate the drug distribution and 3.5 mg of doxorubicin in 50 ml of 0.9% NaCl to evaluate the tissue concentrations and penetration depth, pharmacokinetic properties, and toxicities. All agents were sprayed as aerosols via the nozzle, DreamPen^® (Dalim Biotech, Gangwon, South Korea), with a velocity of 5 km/h at a flow rate of 30 ml/min under a pressure of 7 bars, and capnoperitoneum of 12 mmHg was maintained for 30 min. As a result, RIPAC showed a wider distribution and stronger intensity than PIPAC. Compared with PIPAC, RIPAC demonstrated high values of the tissue concentration in the central, right upper, epigastrium, left upper, left lower, right lower, and right flank regions (median, 375.5-2124.9 vs. 161.7-1240 ng/ml; p ≤ .05), and higher values of the depth of concentrated diffusion and depth of maximal diffusion (median, 232.5-392.7 vs. 116.9-240.1 μm; 291.2-551.2 vs. 250.5-362.4 μm; p ≤ .05) in all regions except for bowels. In RIPAC, the pharmacokinetic properties reflected hemodynamic changes during capnoperitoneum, and there were no related toxicities. Conclusively, RIPAC may have the potential to enhance drug delivery into the peritoneum compared to PIPAC.

Systemic Chemotherapy Including Ramucirumab in Combination With Pressurized Intra-Peritoneal Aerosol Chemotherapy Is a Safe Treatment Option for Peritoneal Metastasis of Gastric Cancer

Background

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a laparoscopic technique for local chemotherapy. It has been used for treatment of peritoneal metastasis of gastric cancer (PM GC) in combination with systemic therapy. VEGFR2 antagonist ramucirumab is a second-line therapy for GC, and has been suspected to cause wound healing disorders.

Methods

This is a retrospective single center cohort study of patients with PM GC, who received PIPAC treatment in combination with systemic chemotherapy with and without ramucirumab. Data on patients’ characteristics and their perioperative courses were collected and complication rates were compared with regard to preoperative use of ramucirumab and time between last dose of systemic therapy and PIPAC treatment.

Results

Fifty patients underwent 90 PIPAC treatments for PM GC in 3 years. Overall postoperative morbidity was 11% with 6% severe complications. The mean interval between systemic therapy and PIPAC was 20 days. Neither the length of interval nor the use of ramucirumab had an effect on complication rates.

Conclusion

Our study suggests that addition of ramucirumab to pre-PIPAC systemic therapy, irrespective of the length of the treatment-free interval before PIPAC, does not increase the risk of postoperative complications and is therefore a safe option for treatment of PM GC.

The emergence of pressurized intraperitoneal aerosol chemotherapy as a palliative treatment option for patients with diffuse peritoneal metastases: a narrative review

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is an emerging palliative treatment for patients with unresectable peritoneal metastases. Potential advantages of PIPAC over current treatment options are a homogeneous intraperitoneal distribution, low local and systemic toxicity, and enhanced tumour penetration. Given these possible benefits, PIPAC is increasingly implemented in many centres worldwide. Scientific research into PIPAC is currently available from in vitro/in vivo/in animal studies, retrospective cohorts in humans, and phase I and II studies in humans. There are no results from randomised trials comparing PIPAC with conventional treatment, such as palliative systemic therapy. This narrative review aimed to provide an overview of the currently available literature on PIPAC. In general, repetitive PIPAC was feasible and safe for patients and operating room personnel. Primary and secondary non-access rates varied from 0-17% and 0-15%, respectively. Iatrogenic bowel injury was observed in 0-3% of PIPAC procedures. CTCAE grade 1-2 complications were common, mostly consisting of abdominal pain, nausea, vomiting, and fatigue. CTCAE grade 3-4 complications were uncommon, occurring on 0-15% of PIPAC procedures. Post-operative mortality rates of 0-2% were reported. The risk of occupational exposure to cytotoxic drugs was very low when strict safety guidelines were followed. Clinical heterogeneity was high in most studies, since, in general, patients with unresectable peritoneal metastases from a variety of primary tumours were included. Also, patients received either PIPAC monotherapy or PIPAC combined with concomitant systemic therapy, and were able to receive PIPAC in any line of palliative treatment. Since the results were generally not stratified for these three important factors, this severely complicates the interpretation of results. Based on the current literature, PIPAC may be regarded as a promising palliative treatment option in patients with diffuse peritoneal metastases. Initial results show that it is feasible and safe. However, well designed and (ideally) randomized controlled trials are urgently needed to determine the additional value of PIPAC in this setting. Until then, PIPAC should preferably be performed in the setting of clinical trials.