Role of immunohistochemistry for interobserver agreement of Peritoneal Regression Grading Score (PRGS) in peritoneal metastasis

Outcome of patients with peritoneal metastasis from ovarian cancer treated with Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC)

Objectives

There are few data on Pressurized IntraPeritoneal Aerosol Chemotherapy with cisplatin and doxorubicin (PIPAC C/D) in women with primary unresectable or recurrent platinum-resistant peritoneal metastasis (PM) from ovarian cancer (OC). We evaluated survival, histological and cytological response, Quality of Life (QoL) and toxicity after PIPAC C/D in these patients.

Methods

Retrospective analysis of patients from the prospective PIPAC-OPC1 and -OPC2 studies. The histological response was evaluated by the Peritoneal Regression Grading Score (PRGS). QoL questionnaires were collected at baseline and after third PIPAC or 60 days. Adverse events were collected until 30 days after the last PIPAC. Demographic and survival data were analysed based on intention to treat. Response, QoL and toxicity were analysed per protocol (≥1 PIPAC).

Results

Twenty-nine patients were included. Five patients (17 %) were non-accessible at PIPAC 1. One patient was excluded due to liver metastases at PIPAC 1. Thus, 23 patients had 76 PIPACs (median 2, range 1-12). Median overall survival was 8.2 months (95 % CI 4.4-10.3) from PIPAC 1. Biopsy data were available for 22 patients, and seven (32 %) patients had a major/complete histological response (PRGS≤2) at PIPAC 3. No cytological conversions were registered. Symptoms and function scores worsened, while emotional scores improved. Three patients had severe adverse reactions (two ileus, one pulmonary embolism); no life-threatening reactions or treatment-related mortality was observed.

Conclusions

PIPAC C/D was feasible and induced histological regression in a substantial proportion of patients with platinum-resistant PM from OC. Larger studies are needed to evaluate impact on survival.

Review on treatment of pleural metastasis and malignant pleural effusion with Pressurized IntraThoracic Aerosol Chemotherapy (PITAC)

Background

Malignant pleural effusion (MPE) is a common and debilitating condition seen in advanced cancer disease, and life-expectancy is short. Symptoms include pain and severe shortness of breath. Current first-line treatment options include pleural drainage using catheters as well as pleurodesis. However, these treatment modalities are often inefficient and patients need repeated procedures. Pressurized IntraThoracic Aerosol Chemotherapy (PITAC) is a minimally invasive procedure, where antineoplastic agents are nebulized under pressure into the pleural space.

Content

We present the preliminary safety, feasibility, and response assessment data for PITAC based on a comprehensive literature review.

Summary

Five retrospective studies reported data on 38 PITACs in 21 patients. Data were heterogeneous and incomplete on several important aspects such as procedure, safety, local effect and long-term outcomes. PITAC seems technically feasible with a low risk of complications and may provide some reduction in MPE in selected cases.

Outlook

PITAC seems feasible, but prospective phase I and II studies are needed to define safety, indications, and efficacy.

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.

What is long-term survival in patients with peritoneal metastasis from gastric, pancreatic, or colorectal cancer? A study of patients treated with systemic chemotherapy and pressurized intraperitoneal aerosol chemotherapy (PIPAC)

Objectives

A definition of long-term survival (LTS) in patients with peritoneal metastasis (PM) from gastric cancer (GC), pancreatic cancer (PC) or colorectal cancer (CRC) treated with systemic chemotherapy and pressurized intraperitoneal aerosol chemotherapy (PIPAC) is lacking. We aimed to define LTS and investigate characteristics and treatment response in patients who reached LTS in data from two prospective trials.

Methods

Retrospective study of patients with GC-, PC-, or CRC-PM from the prospective PIPAC-OPC1 and PIPAC-OPC2 studies. The definition of LTS was based on published systematic reviews and randomized controlled trials. LTS was defined at the time point where 25 % of the patients were alive in these studies. Histology based response was evaluated by the mean Peritoneal Regression Grading Score (PRGS) using biopsies obtained prior to PIPAC 3, and defined by a mean PRGS of ≤2.0 or a decrease of mean PRGS of ≥1, compared to baseline.

Results

LTS was defined at 21 (GC), 15 (PC), and 24 (CRC) months. Fifty-one (47.2 %) patients (nine GC, 17 PC, 25 CRC) reached LTS calculated from the date of PM diagnosis. All but one received palliative chemotherapy before PIPAC, and 37 % received bidirectional treatment. More than 90 % of the LTS patients had response according to PRGS. The mOS from PIPAC 1 was 23.3, 12.4, and 28.5 months for GC, PC, and CRC LTS patients.

Conclusions

Patients with PM from GC, PC, and CRC treated with systemic chemotherapy and PIPAC can reach LTS and most show histological response. Causality must be further investigated.

Response Evaluation in Patients with Peritoneal Metastasis Treated with Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC)

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) directed therapy emerged as a treatment of peritoneal metastasis (PM) a decade ago. The response assessment of PIPAC is not uniform. This narrative review describes non-invasive and invasive methods for response evaluation of PIPAC and summarizes their current status. PubMed and clinicaltrials.gov were searched for eligible publications, and data were reported on an intention-to-treat basis. The peritoneal regression grading score (PRGS) showed a response in 18-58% of patients after two PIPACs. Five studies showed a cytological response in ascites or peritoneal lavage fluid in 6-15% of the patients. The proportion of patients with malignant cytology decreased between the first and third PIPAC. A computed tomography showed stable or regressive disease following PIPAC in 15-78% of patients. The peritoneal cancer index was mainly used as a demographic variable, but prospective studies reported a response to treatment in 57-72% of patients. The role of serum biomarkers of cancer or inflammation in the selection of candidates for and responders to PIPAC is not fully evaluated. In conclusion, response evaluation after PIPAC in patients with PM remains difficult, but PRGS seems to be the most promising response evaluation modality.

Treatment of Peritoneal Metastasis with Pressurized Intraperitoneal Aerosol Chemotherapy: Results from the Prospective PIPAC-OPC2 Study

BACKGROUND

Pressurized Intraperitoneal Aerosol chemotherapy (PIPAC) is a local treatment for peritoneal metastasis (PM). Prospective data are scarce and evaluation of treatment response remains difficult. This study evaluated the use of the Peritoneal Regression Grading score (PRGS) and its prognostic value.

PATIENTS AND METHODS

This was a prospective, controlled phase II trial in patients with PM from gastrointestinal, gynaecological, hepatopancreatobiliary, primary peritoneal, or unknown primary cancer. Patients in performance status 0-1, with a non-obstructed gastrointestinal tract, and a maximum of one extraperitoneal metastasis were eligible. Colorectal or appendiceal PM had PIPAC with oxaliplatin, other primaries had PIPAC with cisplatin and doxorubicin. Biopsies were taken at each PIPAC and evaluated using the PRGS. Quality-of-life questionnaires were reported at baseline and after three PIPACs.

RESULTS

One hundred ten patients were treated with 336 PIPACs (median 3, range 1-12). One hundred patients had prior palliative chemotherapy and 45 patients received bidirectional treatment. Complete or major histological response to treatment (PRGS 1-2) was observed in 38 patients (61%) who had three PIPACs, which was the only independent prognostic factor in a multivariate analysis. The median overall survival (mOS) from PIPAC 1 was 10 months, while patients with PM from gastric, colorectal, and pancreatic cancer had a mOS of 7.4, 16.7, and 8.2 months, respectively. Global health scores were significantly reduced, but patients were less fatigued, nauseated, constipated, and had better appetite after three PIPACs.

CONCLUSIONS

PIPAC with oxaliplatin or cisplatin and doxorubicin was able to induce a major or complete histological response during three PIPACs, which may provide significant prognostic information, both at baseline and after treatment.

Phase I study of intraperitoneal aerosolized nanoparticle albumin based paclitaxel (NAB-PTX) for unresectable peritoneal metastases

Background

Pressurized intraperitoneal aerosolized chemotherapy (PIPAC) is a novel method to treat patients with peritoneal metastases (PM). We aimed to study the tolerability, safety, pharmacokinetics, and tumour response of nanoparticle albumin bound paclitaxel (NAB-PTX) during PIPAC in a Phase I study.

Methods

Eligible patients with biopsy-proven PM from ovarian, breast, gastric, hepatobiliary, or pancreatic origin underwent three PIPAC treatments using NAB-PTX with a four-week interval. The dose of NAB-PTX was escalated from 35 to 140 mg/m² using a Bayesian design to estimate the maximum tolerated dose (MTD).

Findings

Twenty-three patients were included; thirteen (65%) patients combined PIPAC therapy with continued systemic chemotherapy. The most frequent toxicities were liver toxicity and anaemia. Treatment resulted in seven (35%) responders, six (30%) non-responders and seven (35%) patients with stable PM. Systemic absorption of NAB-PTX was slow, with median peak plasma concentrations reached after 3 to 4 h. Median NAB-PTX tumour tissue concentrations suggested accumulation: 14.6 ng/mg, 19.2 ng/mg and 40.8 ng/mg after the first, second and third PIPAC procedure respectively. EORTC QoL and VAS scores remained stable. Overall survival after one year was 57%.

Interpretation

PIPAC with NAB-PTX results in a favourable PK profile and promising anticancer activity in patients with unresectable PM. The MTD and recommended Phase II clinical trial dose are 140 mg/m². In patients with impaired hepatobiliary function, a dose of 112.5 mg/m² is recommended.

Funding

Kom op tegen Kanker (Flemish League against Cancer).

Importance of biopsy site selection for peritoneal regression grading score (PRGS) in peritoneal metastasis treated with repeated pressurized intraperitoneal aerosol chemotherapy (PIPAC)

Objectives

The four-tiered peritoneal regression grading score (PRGS) is used for histological response evaluation in patients with peritoneal metastasis (PM) treated with pressurized intraperitoneal aerosol chemotherapy (PIPAC). Four quadrant biopsies (QBs) from the parietal peritoneum should be assessed by PRGS, but consensus on biopsy site strategy for follow-up biopsies during repeated PIPACs is lacking. We aimed to evaluate whether there is a difference between PRGS in QBs from clips marked PM (QB-CM) compared to biopsies from PM with the visually most malignant features (worst biopsy, WB).

Methods

Prospective, descriptive study. During the first PIPAC, index QBs sites were marked with metal clips. During the second PIPAC, an independent surgical oncologist selected biopsy site for WB and biopsies were taken from QB-CM and WB. One blinded pathologist evaluated all biopsies according to PRGS. From each biopsy, three step sections were stained H&E, followed by an immunostained section, and another three step sections stained H&E.

Results

Thirty-four patients were included from March 2020 to May 2021. Median age 64 years. Maximum mean PRGS in QB-CM at PIPAC 1 was 3.3 (SD 1.2). Maximum mean PRGS in QB-CM at PIPAC 2 was 2.6 (SD 1.2), whereas mean PRGS in WB at PIPAC 2 was 2.4 (SD 1.3). At PIPAC 2, there was agreement between maximum PRGS from QB-CM and PRGS from WB in 21 patients. Maximum PRGS from QB-CM was higher in nine and lower in four patients, compared to PRGS from WB.

Conclusions

Biopsies from QB-CM did not overestimate treatment response compared to biopsies from WB.