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

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.

Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC) Applied to Platinum-Resistant Recurrence of Ovarian Tumor: A Single-Institution Experience (ID: PARROT Trial)

BACKGROUND

We aimed to investigate the therapeutic efficacy and safety of Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC) in platinum-resistant recurrence of ovarian cancer and peritoneal carcinomatosis, while our secondary endpoint was to establish any changes in quality of life estimated via the EORTC QLQ-30 and QLQ-OV28 questionnaires.

METHODS

In this monocentric, single-arm, phase II trial, women were prospectively recruited and every 28-42 days underwent courses of PIPAC with doxorubicin 2.1 mg/m2 followed by cisplatin 10.5 mg/m2 via sequential laparoscopy.

RESULTS

Overall, 98 PIPAC procedures were performed on 43 women from January 2016 to January 2020; three procedures were aborted due to extensive intra-abdominal adhesions. The clinical benefit rate (CBR) was reached in 82% of women. Three cycles of PIPAC were completed in 18 women (45%), and 13 (32.5%) and 9 (22.5%) patients were subjected to one and two cycles, respectively. During two PIPAC procedures, patients experienced an intraoperative intestinal perforation. There were no treatment-related deaths. Nineteen patients showed no response according to the Peritoneal Regression Grading Score (PRGS) and 8 patients showed minor response according to the PRGS. Median time from ovarian cancer relapse to disease progression was 12 months (95% confidence interval [CI] 6.483-17.517), while the median overall survival was 27 months (95% CI 20.337-33.663). The EORTC QLQ-28 and EORTC QLQ-30 scores did not worsen during therapy.

CONCLUSIONS

PIPAC seems a feasible approach for the treatment of this subset of patients, without any impact on their quality of life. Since this study had a small sample size and a single-center design, future research is mandatory, such as its application in addition to systemic chemotherapy.

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.

Safety and Efficacy of Oxaliplatin Pressurized Intraperitoneal Aerosolized Chemotherapy (PIPAC) in Colorectal and Appendiceal Cancer with Peritoneal Metastases: Results of a Multicenter Phase I Trial in the USA

BACKGROUND

Pressurized intraperitoneal aerosolized chemotherapy (PIPAC) is a laparoscopic locoregional treatment for peritoneal metastases (PM) from colorectal cancer (CRC) or appendiceal cancer (AC) in patients who cannot undergo cytoreductive surgery (CRS). While PIPAC has been studied in Europe and Asia, it has not been investigated in the USA.

PATIENTS AND METHODS

We evaluated PIPAC with 90 mg/m2 oxaliplatin alone (cycle 1) and preceded by systemic chemotherapy with fluorouracil (5-FU) and leucovorin (LV) (cycle 2-3) as a multicenter prospective phase I clinical trial (NCT04329494). The primary endpoint was treatment-related adverse events (AEs). Secondary endpoints included survival and laparoscopic, histologic, and radiographic response.

RESULTS

12 patients were included: 8 with CRC and 4 with AC. Median prior chemotherapy cycles was 2 (interquartile range (IQR) 2-3). All patients were refractory to systemic oxaliplatin-based chemotherapy. Median peritoneal carcinomatosis index (PCI) was 28 (IQR 19-32). Six (50%) of twelve patients completed three PIPAC cycles. No surgical complications or dose-limiting toxicities were observed. Two patients developed grade 3 treatment-related toxicities (one abdominal pain and one anemia). Median overall survival (OS) was 12.0 months, and median progression-free survival (PFS) was 2.9 months. OS was correlated with stable disease by Response Evaluation Criteria in Solid Tumors (RECIST) criteria but not with laparoscopic response by PCI or histologic response by peritoneal regression grading system (PRGS).

CONCLUSIONS

This phase I trial in the USA demonstrated safety, feasibility, and early efficacy signal of PIPAC with oxaliplatin and chemotherapy in patients with PM from AC or CRC who are refractory to standard lines of systemic chemotherapy.

Peritoneal regression grading score (PRGS): first evidence for independent predictive and prognostic significance

Objectives

The peritoneal regression grading score (PRGS) is a four-tied pathologic score measuring tumor regression in biopsies from patients with peritoneal metastasis (PM) receiving chemotherapy.

Methods

This retrospective analysis of a prospective registry (NCT03210298) analyses 97 patients with isolated PM under palliative chemotherapy. We examined the predictive value of the initial PRGS for overall survival (OS) and the prognostic value of PRGS in repeated peritoneal biopsies.

Results

The 36 (37.1 %) patients with an initial mean PRGS≤2 had a longer median OS (12.1 months, CI 95 % 7.8-16.4) vs. 8.0 months (CI 95 % 5.1-10.8 months) in 61 (62.9 %) patients with PRGS≥3 (p=0.02) After stratification, the initial PRGS was an independent predictor of OS (Cox-regression, p<0.05). Out of 62 patients receiving≥two chemotherapy cycles, 42 (67.7 %) had a histological response (defined as a lower or stable mean PRGS in successive therapy cycles), and 20 (32.3 %) progressed (defined as an increasing mean PRGS). PRGS response was associated with a longer median OS (14.6 months, CI 5-95 % 6.0-23.2) vs. 6.9 (CI 5-95 % 0.0-15.9) months. PRGS response was prognostic in the univariate analysis (p=0.017). Thus, PRGS had both a predictive and prognostic significance in patients with isolated PM receiving palliative chemotherapy in this patient cohort.

Conclusions

This is the first evidence for the independent predictive and prognostic significance of PRGS in PM. These encouraging results need validation in an adequately powered, prospective study.

The role of cytology in patients undergoing pressurized intraperitoneal aerosol chemotherapy (PIPAC) treatment for peritoneal carcinomatosis

Objectives

Cytology of ascites or peritoneal washing is a routine part of staging of peritoneal metastases (PM). We aim to determine value of cytology in patients undergoing pressurized intraperitoneal aerosol chemotherapy (PIPAC).

Methods

Single-center retrospective cohort study included consecutive patients having PIPAC for PM of different primary between January 2015 and January 2020.

Results

A total of 75 patients (median 63 years (IQR 51-70), 67 % female) underwent a total of 144 PIPAC. At PIPAC 1 59 % patients had positive and 41 % patients had negative cytology. Patients with negative and positive cytology only differed in terms of symptoms of ascites (16% vs. 39 % respectively, p=0.04), median ascites volume (100 vs. 0 mL, p=0.01) and median PCI (9 vs. 19, p<0.01). Among 20 patients who completed 3 PIPACs (per protocol), cytology changed in one from positive to negative, and in two from negative to positive. Median overall survival was 30.9 months in the per protocol group and 12.9 months in patients having <3 PIPACs (=0.519).

Conclusions

Positive cytology under PIPAC treatment is more frequently encountered in patients with higher PCI and symptomatic ascites. Cytoversion was rarely observed and cytology status had no impact on treatment decisions in this cohort.

Histological tumor response predicts clinical outcome in patients with colorectal peritoneal metastasis treated with preoperative chemotherapy followed by cytoreduction and HIPEC

Objectives

Up to one quarter of the patients with colorectal cancer (CRC) develop peritoneal carcinomatosis (PM). The aims of this retrospective study were to characterize the histological response of the PM of CRC to preoperative chemotherapy and evaluate the potential prognostic value, in terms of survival.

Methods

This retrospective unicentric study evaluated a group of 30 patients treated between 2010 and 2020 at the São João University Hospital Center with preoperative chemotherapy, followed by cytoreduction surgery plus hyperthermic intraperitoneal chemotherapy. The evaluation of the histological response was done using two scores: the tumor regression grading (TRG) and the peritoneal regression grading score (PRGS).

Results

Mean post-procedure survival is higher in the PRGS 1–2 group (74.19 months) vs. the PRGS 3–4 group (25.27 months) (p=0.045), as well as in the TRG 1–2 group (74.58 months) vs. TRG 4–5 (25.27 months) (p=0.032). As for progression-free survival (PFS), the PRGS 1–2 group had a mean value of 58.03 months vs. PRGS 3–4 which had 11.67 months (p=0.002). Similar was observed with the TRG 1–2 group, which had a mean PFS of 61.68 months vs. TRG 4–5 with 11.67 months (p=0.003).

Conclusions

A better histological response to preoperative chemotherapy, represented as a lower PRGS and TRG value, is associated with longer post-procedure survival and progression-free survival in this group of patients. That is, these two scores have prognostic value.

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.

Peritoneal regression grading score (PRGS) in peritoneal metastasis: how many biopsies should be examined?

Objectives

The four-tied peritoneal regression grading score (PRGS) is increasingly used to evaluate the response of peritoneal metastases (PM) to chemotherapy. The minimal number of peritoneal biopsies needed for PRGS determination remains unclear.

Methods

A prospective cohort of 89 PM patients treated with 210 pressurized intraperitoneal aerosol chemotherapy (PIPAC) cycles was investigated. Four biopsies from every abdominal quadrant were recommended. Histological tumor response was defined as a stable or decreasing mean PRGS between therapy cycles, progression increasing. We compared the diagnostic uncertainty induced by missing biopsies to the histological response.

Results

A total of 49 patients had at least two PIPAC and were eligible for therapy response assessment. Mean PRGS decreased from 2.04 (CI 5-95% 1.85-2.27) to 1.79 (CI 5-95% 1.59-2.01), p=0.14, as a proof of therapy effectiveness. 35 (71.4%) patients had a stable or decreasing PRGS (therapy response), 14 (28.6%) a PRGS increase (disease progression). Histology showed agreement between four biopsies in 42/210 laparoscopies (20%), between ≥3 biopsies in 103 (49%), and between ≥2 biopsies in 169 laparoscopies (81%). Mean loss of information with one missing biopsy was 0.11 (95% CI=0.13) PRGS points, with two missing biopsies 0.18 (95% CI 0.21). In 9/49 patients (18.3%), the loss of information with one less biopsy exceeded the change in PRGS under therapy.

Conclusions

A minimum of three biopsies is needed to diagnose PM progression with an accuracy superior to 80%. Missing biopsies often result in a false diagnosis of tumor progression.

Feasibility and Safety of Taxane-PIPAC in Patients with Peritoneal Malignancies-a Retrospective Bi-institutional Study

Taxanes have a favorable pharmacokinetic profile for intraperitoneal application. We report our initial experience with taxane-PIPAC (pressurized intraperitoneal chemotherapy) for unresectable peritoneal metastases from different primary sites in terms of safety, feasibility, response rate, and conversion to resectability. In this retrospective study, PIPAC was performed alone or in combination with systemic chemotherapy. Paclitaxel was used as a single agent, whereas docetaxel was used in combination with cisplatin-adriamycin or oxaliplatin-adriamycin. From December 2019 to December 2021, 47 patients underwent 82 PIPAC procedures (1 PIPAC in 55.3%, 2 in 29.7%, 3 in 14.8%). The most common primary sites were ovarian cancer (31.9%), gastric cancer (23.4%), and colorectal cancer (21.2%). Docetaxel-cisplatin-adriamycin was used in 33 (70.2%) patients, docetaxel-oxaliplatin-adriamycin in 12 (25.5%), and paclitaxel alone in 2 (4.2%) patients. Grade 1-2 complications were observed in 24 (51%) and grade 3-4 complications in 6 (12.7%) patients (8.5% of 82 PIPACs). 16/47 (34.0%) patients had a clinical response to PIPAC. The mean PCI was 25.9 ± 9.2 for the first PIPACs and 22.4 ± 9 for the subsequent PIPACs with an average reduction of 3.6 points [change in PCI ranged from - 14 to + 8]. The PRGS was 1/2 in 4/47 (8.5%) patients (19.0% patients with > 1 PIPAC). A reduction in ascites was observed in 35.4% presenting with ascites. Nine (19.1%) patients had conversion to operability leading to a subsequent cytoreductive surgery in 8 (17%) patients. PIPAC with docetaxel is feasible and safe. The role of PIPAC with both docetaxel and paclitaxel either alone or in combination with other drugs should be investigated in prospective studies.

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.

Feasibility and Safety of Oxaliplatin-Based Pressurized Intraperitoneal Aerosol Chemotherapy With or Without Intraoperative Intravenous 5-Fluorouracil and Leucovorin for Colorectal Peritoneal Metastases: A Multicenter Comparative Cohort Study

BACKGROUND

This retrospective multicenter cohort study compared the feasibility and safety of oxaliplatin-based pressurized intraperitoneal aerosol chemotherapy (PIPAC-Ox) with or without intraoperative intravenous 5-fluorouracil (5-FU) and leucovorin (L).

METHODS

Our study included consecutive patients with histologically proven unresectable and isolated colorectal peritoneal metastases (cPM) treated with PIPAC-Ox in seven tertiary referral centers between January 2015 and April 2020. Toxicity events and oncological outcomes (histological response, progression-free survival, and overall survival) were compared between patients who received intraoperative intravenous 5-FU/L (PIPAC-Ox + 5-FU/L group) and patients who did not (PIPAC-Ox group).

RESULTS

In total, 101 patients (263 procedures) were included in the PIPAC-Ox group and 30 patients (80 procedures) were included in the PIPAC-Ox + 5-FU/L group. Common Terminology Criteria for Adverse Events v4.0 grade 2 or higher adverse events occurred in 48 of 101 (47.5%) patients in the PIPAC-Ox group and in 13 of 30 (43.3%) patients in the PIPAC-Ox + 5-FU/L group (p = 0.73). The complete histological response rates according to the peritoneal regression grading score were 27% for the PIPAC-Ox + 5-FU/L group and 18% for the PIPAC-Ox group (p = 0.74). No statistically significant differences were observed in overall or progression-free survival between the two groups.

CONCLUSIONS

The safety and feasibility of PIPAC-Ox + 5-FU/L appears to be similar to the safety and feasibility of PIPAC-Ox alone in patients with unresectable cPM. Oncological outcomes must be evaluated in larger studies.

Assessing Post-Treatment Pathologic Tumor Response in Female Genital Tract Carcinomas: An Update

In the last decades, several new therapeutic strategies have been introduced in the field of gynecologic oncology. These include neoadjuvant chemotherapy for high-grade serous tubo-ovarian carcinoma, hormonal fertility-sparing strategies for endometrial cancer, pressurized intraperitoneal aerosol chemotherapy (PIPAC) for surgically incurable peritoneal metastasis, and neoadjuvant treatments for locally advanced cervical carcinomas. All these recent advances lead to the development of novel scoring systems for the evaluation of pathological response related to specific treatments. In this regard, pathological evaluation of the morphological modifications related to these treatments and the definition of a tumor regression grading score have been introduced in clinical practice in order to achieve a more efficient prognostic stratification of patients affected by gynecological malignancies. The aim of the present paper is to provide a detailed review on the post-treatment pathological scoring systems in patients affected by gynecological malignancies.

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.

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.

Histological regression of gastrointestinal peritoneal metastases after systemic chemotherapy

Objectives

Peritoneal metastases (PM) are relatively resistant to systemic chemotherapy, and data on histological response to therapy is rare. The aim of this study was to quantify the treatment response of PM after systemic chemotherapy.

Methods

Retrospective monocentric cohort study of 47 consecutive patients with PM from gastrointestinal origin undergoing surgery (cytoreduction: CRS + Hyperthermic IntraPEritoneal Chemotherapy [HIPEC] or Pressurized IntraPeritoneal Aerosol Chemotherapy [PIPAC]) after prior systemic chemotherapy from 1.2015 to 3.2019. Tumor response was assessed using the 4-scale Peritoneal Regression Grading System (PRGS) (4: vital tumor to 1: complete response).

Results

Patients had a median of 2 (range: 1-7) lines and 10 (3-39) cycles of prior systemic chemotherapy. A median of four biopsies (range: 3-8) was taken with a total of 196 analyzed specimens. Twenty-four biopsies (12%) showed no histological regression (PRGS4), while PRGS 3, two and one were diagnosed in 37 (19%), 39 (20%), and 69 (49%) specimens, respectively. A significant heterogeneity was found between peritoneal biopsies in 51% patients. PRGS correlated strongly with peritoneal spread (PCI, p<0.0001), and was improved in patients with more than nine cycles of systemic chemotherapy (p=0.04). Median survival was higher in patients with PRGS < 1.8 (Quartiles one and 2) than higher (Q3 and Q4), but the difference did not reach significance in this small cohort.

Conclusions

PRGS is an objective too to describe histological response of PM of GI origin after systemic chemotherapy. This response differs significantly between patients, allowing to distinguish between chemosensitive and chemoresistant tumors.

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 with oxaliplatin (PIPAC-OX) in patients with colorectal peritoneal metastases-a systematic review

Pressurized intraperitoneal aerosol chemotherapy with oxaliplatin (PIPAC-OX) is increasingly used as a palliative treatment option for patients with colorectal peritoneal metastases (CPM). The present study aimed to systematically review all clinical studies reporting safety and efficacy outcomes of PIPAC-OX in patients with CPM. PubMed, EMBASE, The Cochrane Library, and CINAHL were systematically searched to identify all clinical studies that included at least one patient with CPM treated with PIPAC-OX and reported one of the following outcomes: adverse events, tumor response, quality of life, secondary cytoreductive surgery, progression-free survival, overall survival, and environmental safety of PIPAC-OX. Results were narratively described. Of 28 included studies, only 14 non-comparative studies separately reported at least one outcome of PIPAC-OX for CPM, of which only two studies specifically focused on this group. These 14 studies reported adverse events (5 studies), tumor response (5 studies), secondary cytoreductive surgery (4 studies), progression-free survival (1 study), overall survival (5 studies), and environmental safety (2 studies). Except for 5 studies (describing 26 patients), none of the included studies stratified their results for PIPAC-OX monotherapy and PIPAC-OX with concomitant systemic therapy, and none of the studies reporting survival outcomes stratified results for line of palliative treatment, complicating interpretation. No PIPAC-OX related deaths were reported. No occupational platinum was detected during PIPAC-OX. The available evidence regarding PIPAC-OX for CPM is limited and difficult to interpret. Despite these limitations, PIPAC-OX appears safe in patients with CPM and safe for operating personnel. To increase insight in the role of PIPAC-OX in this setting, investigators of ongoing and future studies are encouraged to report separate outcomes of PIPAC-OX for CPM, to stratify their results for PIPAC-OX monotherapy and PIPAC-OX with concomitant systemic therapy, and to stratify survival results for line of palliative treatment.

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.

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.

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.

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.

Next-generation sequencing and histological response assessment in peritoneal metastasis from pancreatic cancer treated with PIPAC

Background

Peritoneal metastasis from pancreatic cancer (PM-PC) may be treated with repeated pressurised intraperitoneal aerosol chemotherapy (PIPAC). Utility of next-generation sequencing (NGS) to detect cancer-related mutations in peritoneal quadrant biopsies (QBs) and peritoneal fluid (PF) after systemic and PIPAC treatment has not been evaluated. Around 90% of pancreatic cancers (PCs) harbour a KRAS mutation, making PC ideal for the evaluation of this aspect.

Aims

Evaluation of PM-PC in terms of (1) histological response to PIPAC using Peritoneal Regression Grading Score (PRGS), (2) clinical characteristics and (3) frequency of mutations in QBs and PF before and after PIPAC.

Methods

Peritoneal QBs and PF were obtained prior to each PIPAC. NGS for 22 cancer-related genes was performed on primary tumours, QBs and PFs. Response was assessed by the four-tiered PRGS.

Results

Sixteen patients treated with a median of three PIPAC procedures were included. The mean PRGS was reduced from 1.91 to 1.58 (p=0.02). Fifty-seven specimens (13 primary tumours, 2 metastatic lymph nodes, 16 PFs and 26 QB sets) were analysed with NGS. KRAS mutation was found in 14/16 patients (87.50%) and in QBs, primary tumours and PF in 8/12 (66.67%), 8/13 (61.53%) and 6/9 (66.67%). The median overall survival was 9.9 months (SE 1.5, 95% CI 4.9 to 13.9).

Conclusion

PIPAC induces histological response in the majority of patients with PM-PC. KRAS mutation can be found in PM-PC after PIPAC at a frequency similar to the primaries. NGS may be used to detect predictive mutations in PM-PC of various origins, also when only post-PIPAC QBs or PFs are available.