Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy to Treat Pseudomyxoma Peritonei of Ovarian Origin: A Retrospective French RENAPE Group Study.

BACKGROUND: Ovarian pseudomyxoma peritonei (OPMP) are rare, without well-defined therapeutic guidelines. We aimed to evaluate cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) to treat OPMP. METHODS: Patients from the French National Network for Rare Peritoneal Tumors (RENAPE) database with proven OPMP treated by CRS/HIPEC and with histologically normal appendix and digestive endoscopy were retrospectively included. Clinical and follow-up data were collected. Histopathological and immunohistochemical features were reviewed. RESULTS: Fifteen patients with a median age of 56 years were included. The median Peritoneal Cancer Index was 16. Following CRS, the completeness of cytoreduction (CC) score was CC-0 for 9/15 (60%) patients, CC-1 for 5/15 (33.3%) patients, and CC-2 for 1/15 (6.7%) patients. The median tumor size was 22.5 cm. After pathological review and immunohistochemical studies, tumors were classified as Group 1 (mucinous ovarian epithelial neoplasms) in 3/15 (20%) patients; Group 2 (mucinous neoplasm in ovarian teratoma) in 4/15 (26.7%) patients; Group 3 (mucinous neoplasm probably arising in ovarian teratoma) in 5/15 (33.3%) patients; and Group 4 (non-specific group) in 3/15 (20%) patients. Peritoneal lesions were OPMP pM1a/acellular, pM1b/grade 1 (hypocellular) and pM1b/grade 3 (signet-ring cells) in 13/15 (86.7%), 1/15 (6.7%) and 1/15 (6.7%) patients, respectively. Disease-free survival analysis showed a difference (p = 0.0463) between OPMP with teratoma/likely-teratoma origin (groups 2 and 3; 100% at 1, 5, and 10 years), and other groups (groups 1 and 4; 100%, 66.6%, and 50% at 1, 5, and 10 years, respectively). CONCLUSION: These results suggested that a primary therapeutic strategy using complete CRS/HIPEC for patients with OPMP led to favorable long-term outcomes.

The 2022 PSOGI International Consensus on HIPEC Regimens for Peritoneal Malignancies: Methodology.

BACKGROUND: A group of experts from the Peritoneal Surface Oncology Group International (PSOGI) and the BIG-RENAPE group carried out a consensus among surgeons experienced in treating peritoneal malignancies from around the world to derive recommendations on indications of hyperthermic intraperitoneal chemotherapy (HIPEC), choice and details of HIPEC regimens, and areas for future research. This manuscript describes the methodology of achieving this consensus and the degree of participation of experts. METHODS: The Delphi technique was used and the questionnaire comprised three categories: evidence-based recommendations using the GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) system with the PICO (patient, intervention, comparison, and outcome) method, an opinion survey, and research recommendations. A consensus was achieved if any one option had >50% of votes, or positive or negative recommendations combined had > 70% of votes. RESULTS: Of the 145 experts solicited, 71.1% in round I and 72.2% in round II took the survey. Participation was highest among surgeons treating both gastrointestinal and gynecological malignancies. Of 113 questions, after round I, a consensus was achieved for 72 (63.7%) questions, and after the second round, consensus was achieved for another 22 (19.4%) questions, making a total of 94 (83.1%) questions for which a consensus was achieved. CONCLUSION: This consensus was carried out using a thorough review of literature and robust rating of evidence, and included key experts and opinion leaders from across the world. The results could guide clinicians on the use of HIPEC, both in their day-to-day clinical practice and in designing clinical trials.

The 2022 PSOGI International Consensus on HIPEC Regimens for Peritoneal Malignancies: Epithelial Ovarian Cancer.

BACKGROUND AND AIM: We report the results of an international consensus on hyperthermic intraperitoneal chemotherapy (HIPEC) regimens for epithelial ovarian cancer (EOC) performed with the following goals: To define the indications for HIPEC To identify the most suitable HIPEC regimens for each indication in EOC To identify areas of future research on HIPEC To provide recommendations for some aspects of perioperative care for HIPEC METHODS: The Delphi technique was used with two rounds of voting. There were three categories of questions: evidence-based recommendations [using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system with the patient, intervention, comparator, and outcome (PICO) method], an opinion survey, and research recommendations. RESULTS: Seventy-three (67.5%) of 108 invited experts responded in round I, and 68 (62.9%) in round II. Consensus was achieved for 34/38 (94.7%) questions. However, a strong positive consensus that would lead to inclusion in routine care was reached for only 6/38 (15.7%) questions. HIPEC in addition to interval cytoreductive surgery (CRS) received a strong positive recommendation that merits inclusion in routine care. Single-agent cisplatin was the only drug recommended for routine care, and OVHIPEC-1 was the most preferred regimen. The panel recommended performing HIPEC for a minimum of 60 min with a recommended minimum intraabdominal temperature of 41°C. Nephroprotection with sodium thiosulfate should be used for cisplatin HIPEC. CONCLUSIONS: The results of this consensus should guide clinical decisions on indications of HIPEC and the choice and various parameters of HIPEC regimens and could fill current knowledge gaps. These outcomes should be the basis for designing future clinical trials on HIPEC in EOC.

Role of Hyperthermic Intraperitoneal Chemotherapy Combined with Cytoreductive Surgery as Consolidation Therapy for Advanced Epithelial Ovarian Cancer.

BACKGROUND: Patients with advanced epithelial ovarian cancer who undergo incomplete surgery followed by six cycles of chemotherapy could benefit from second-look or consolidation cytoreductive surgery (CCRS). The primary goal of this study was to evaluate the overall survival (OS) in patients undergoing complete CCRS and the factors affecting survival. The secondary goal was to study the benefit of hyperthermic intraperitoneal chemotherapy (HIPEC) in these patients. METHODS: This was a retrospective analysis of 173 patients with CCRS with (n = 118) or without (n = 55) HIPEC treated at 12 French centers. Only patients having a completeness of cytoreduction (CC) 0/1 resection and a minimum of 5 years of follow-up were included. HIPEC was performed systematically for all patients except those treated at the four centers that did not perform HIPEC. RESULTS: The median Peritoneal Cancer Index was 6 (range 0-33). Closed HIPEC was performed in 59 (34.1%) patients and open HIPEC was performed in 56 (32.3%) patients. Grade 3-4 complications occurred in 64 (36.9%) patients. The median OS was 35.67 months (95% confidence interval [CI] 29.8-46.1) and was significantly longer for CCRS + HIPEC (31.4 months without HIPEC and 42.5 months with HIPEC; p = 0.022). On multivariate analysis, closed HIPEC (hazard ratio [HR] 0.46, 95% CI 0.29-0.73; p < 0.001) resulted in a longer OS, and age > 65 years (HR 2.17, 95% CI 1.14-4.11; p = 0.018) and bowel resection (HR 1.98, 95% CI 1.27-3.08; p = 0.020) led to a shorter OS. On multivariate logistic regression analysis, closed HIPEC (odds ratio 0.18; p = 0.001) was associated with a lower risk of dying at 5 years. CONCLUSIONS: CCRS was performed with an acceptable morbidity and resulted in good overall survival. The role of HIPEC in addition to CCRS should be evaluated in prospective, randomized studies and the closed technique prospectively compared with the open technique.

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.

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.

Cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) vs CRS alone for treatment of endometrial cancer with peritoneal metastases: a multi-institutional study from PSOGI and BIG RENAPE groups.

OBJECTIVE: To investigate the benefit of cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) for the treatment of endometrial peritoneal carcinomatosis compared to CRS alone. METHODS: We conducted a retrospective multicentre study of patients from experienced centres in treating peritoneal malignancies from 2002 to 2015. Patients who underwent surgery for peritoneal evolution of endometrial cancer (EC) were included. Two groups of 30 women were matched and compared: "CRS + HIPEC" which used HIPEC after CRS, and "CRS only" which did not use HIPEC. We analysed clinical, pathologic and treatment data for patients with peritoneal metastases from EC. The outcome measures were morbidity, overall survival (OS), and progression-free survival (PFS). RESULTS: In "CRS plus HIPEC" group, 96.7% of women were treated for recurrence, while in "CRS only" 83.3 were treated for primary disease. There was no significant difference between Peritoneal Carcinomatosis Index at laparotomy or Completeness of Cytoreduction score. Grade III and IV complications rates did not significantly differ between "CRS plus HIPEC" group and "CRS only" group (20.7% vs 20.7%, p = 0.739). Survival analysis showed no statistical difference between both groups. Median OS time was 19.2 months in "CRS plus HIPEC" group and 29.7 months in "CRS only" group (p = 0.606). Median PFS survival time was 10.7 months in "CRS plus HIPEC" group and 13.1 months in "CRS only" group (p = 0.511). CONCLUSION: The use of HIPEC combined to CRS did not have any significance as regard the DFS and OS over CRS alone in patients with primary or recurrent peritoneal metastasis of endometrial cancer.

Half of Postoperative Deaths After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Could be Preventable: A French Root Cause Analysis on 5562 Patients.

OBJECTIVE: To perform a retrospective root-cause analysis of postoperative death after CRS and HIPEC procedures. BACKGROUND: The combination of CRS and HIPEC is an effective therapeutic strategy to treat peritoneal surface malignancies, however it is associated with significant postoperative mortality. METHODS: All patients treated with a combination of CRS and HIPEC between January 2009 and December 2018 in 22 French centers and died in the hospital, were retrospectively analyzed. Perioperative data of the 101 patients were collected by a local senior surgeon with a sole junior surgeon. Three independent experts investigated the typical root cause of death and provided conclusions on whether postoperative death was preventable (PREV group) or not (NON-PREV group). A typical root cause of preventable postoperative death was classified on a cause-and-effect diagram. RESULTS: Of the 5562 CRS+HIPEC procedures performed, 101 in-hospital deaths (1.8%) were identified, of which a total of 18 patients of 70 years old and above and 20 patients with ASA score of 3. Etiology of peritoneal disease was mainly colorectal. A total of 54 patients (53%) were classified in the PREV group and 47 patients (47%) in the NON-PREV group. The results of the study show that in the PREV group, WHO performance status 1-2 was more frequent and the Median Peritoneal Cancer Index was higher compared with those of the NON-PREV group. The cause of death in the PREV group was classified as: (i) preoperatively for debatable indication (59%), (ii) intraoperatively (30%) and (iii) postoperatively in 17 patients (31%). A multifactorial cause of death was found in 11 patients (20%). CONCLUSION: More than half of the postoperative deaths after combined CRS and HIPEC may be preventable, mainly by following guidelines regarding preoperative selection of the patients and adequate intraoperative decisions.

HIPEC Methodology and Regimens: The Need for an Expert Consensus.

BACKGROUND: Hyperthermic intraperitoneal chemotherapy (HIPEC) is performed with a wide variation in methodology, drugs, and other elements vital to the procedure. Adoption of a limited number of regimens could increase the collective experience of peritoneal oncologists, make comparison between studies more meaningful, and lead to a greater acceptance of results from randomized trials. This study aimed to determine the possibility of standardizing HIPEC methodology and regimens and to identify the best method of performing such a standardization. METHODS: A critical review of preclinical and clinical studies evaluating the pharmacokinetic aspects of different HIPEC drugs and drug regimens, the impact of hyperthermia, and the efficacy of various HIPEC regimens as well as studies comparing different regimens was performed. RESULTS: The preclinical and clinical data were limited, and studies comparing different regimens were scarce. Many of the regimens were neither supported by preclinical rationale or data nor validated by a dose-escalating formal phase 1 trial. All the regimens were based on pharmacokinetic data and did not take chemosensitivity of peritoneal metastases into account. Personalized medicine approaches such as patient-derived tumor organoids could offer a solution to this problem, although clinical validation is likely to be challenging. CONCLUSIONS: Apart from randomized trials, more translational research and phases 1 and 2 studies are needed. While waiting for better preclinical and clinical evidence, the best way to minimize heterogeneity is by an expert consensus that aims to identify and define a limited number of regimens for each indication and primary site. The choice of regimen then can be tailored to the patient profile and its expected toxicity and the methodology according regional factors.

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

AIMS: The peritoneal regression grading score (PRGS) and peritoneal cytology (PC) assess response to chemotherapy in peritoneal metastasis (PM) in a setting of palliative treatment by pressurized intraperitoneal aerosol chemotherapy (PIPAC). Progression has been defined as an increase of PRGS between first and third PIPAC procedures (iPRGS). iPRGSand positive peritoneal cytology were not associated with prognostic impact. These results may be explained by a lack of statistical power. Also, it is not known whether the mean or the highest PRGS among taken peritoneal biopsies bears the highest clinical value. We therefore conducted the largest prospective study to investigate the prognostic impact of PGRS, PC, and their combination, designated as combined progression index (CPI). METHODS AND RESULTS: Patients with PM who underwent >3 PIPAC (n = 112) between December 2016 and February 2019 were prospectively included. A significant difference in OS and PFS according to CPI (used highest value of PRGS) was found (OS: CPI-, 83.3, 95% CI [49.8; NA] vs. CPI+, 48.1, 95% CI [38.5; 66.4] months; and PFS (respectively, 59.7, 95% CI [43.0; 96.0] vs. 33.7, 95% CI [30.4; 44.2] months). PRGS or PC had no independent prognostic impact. CPI+ was an independent predictor of worse prognosis, in OS (HR = 5.24, 95% CI [2.07; 13.26]), and PFS (HR = 4.41, 95% CI [1.40; 13.88]). CONCLUSIONS: The CPI based on highest PRGS and PC was found to be independently associated with a worse prognosis for OS and for PFS in the setting of peritoneal metastasis. These results indicate that it should be of interest to systematically take peritoneal fluid for cytological examination and to implement the CPI in the therapeutic decision-making process in the context of PIPAC.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) might increase the risk of anastomotic leakage compared to HIPEC: an experimental study.

BACKGROUND: Pressurized intraperitoneal aerosol chemotherapy (PIPAC) and hyperthermic intraperitoneal chemotherapy (HIPEC) are technics proposed to treat patients with peritoneal carcinomatosis, in different settings. There is some concern about an over-risk of anastomotic leakage (AL) with PIPAC jeopardizing a combination with cytoreductive surgery. This study used a healthy swine model to compare the postoperative AL rate between PIPAC and HIPEC with digestive resection and to analyze macrocirculation and microcirculation parameters. METHODS: Segmental colonic resection with a handsewn anastomosis was performed on 16 healthy pigs; 8 pigs had a PIPAC procedure with 7.5 mg/m2 cisplatin (PIPAC group), and 8 pigs had a closed HIPEC procedure with 70 mg/m2 cisplatin and 42 °C as the target intraperitoneal temperature (HIPEC group). Pigs were kept alive for 8 days, then sacrificed and autopsied to look for AL, which was defined as local abscess or digestive fluid leakage when pressure was applied to the anastomosis. Food intake, weight, and core temperature were monitored postoperatively. Macrocirculation (heart rate, systolic blood pressure) and microcirculation parameters (percentage of perfused vessels, perfused vessels density, DeBacker score) were evaluated intraoperatively at five timepoints. Results were compared between pigs with AL and those without. RESULTS: The HIPEC group had no AL, but 3 of 8 pigs (37.5%) had AL in the PIPAC group (p = 0.20). Heart rate and core temperature showed perioperative increases in the HIPEC group. Intraoperatively, heart rate was higher in the HIPEC group at the two last timepoints (123 vs. 93 bpm, p = 0.031, and 110 vs. 85 bpm, p = 0.010, at timepoints 3 and 4, respectively). Other macrocirculatory and microcirculatory parameters showed no significant differences. CONCLUSION: In this healthy swine model, PIPAC might have increased AL incidence compared to HIPEC. This potential over-risk did not seem to be related to changes in the microcirculation. PIPAC should probably not be used with digestive resection and should be avoided in cases of perioperative serosal injury.

PIPAC versus HIPEC: cisplatin spatial distribution and diffusion in a swine model.

Purpose: Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a novel approach for delivering intraperitoneal chemotherapy and offers perspective in the treatment of peritoneal carcinomatosis. Concept is based on a 12 mmHg capnoperitoneum loaded with drug changed in microdoplets. It was postulated to guarantee a more homogeneous drug distribution and tissular uptake than hyperthermic intraperitoneal chemotherapy (HIPEC). The aim of this study was to compare cisplatin peritoneal distribution and pharmacokinetic between HIPEC and PIPAC procedures in a healthy swine model.Methods: Two groups of eight pigs underwent either HIPEC with cisplatin (70 mg/m2) at 43 °C for 60 min, or PIPAC with cisplatin (7.5 mg/m2) for 30 min. Postoperatively, peritoneal areas were biopsied allowing peritoneal cavity cartography. Tissular and plasmatic cisplatin concentrations were analyzed.Results: Cisplatin distribution was heterogeneous in both the groups with higher concentrations obtained closed to the delivery sites. Median total platinum peritoneal concentration by pig was higher in the HIPEC group than in the PIPAC group (18.0 µg/g versus 4.3 µg/g, p < .001) but the yield was 2.2 times better with PIPAC. Platinum concentrations were higher in the HIPEC group in all stations. At each time-point, cisplatin plasmatic concentrations were higher in the HIPEC group (p < .001) but beneath the toxicity threshold.Conclusions: With doses used in clinical practice, HIPEC guaranteed a higher cisplatin peritoneal uptake than PIPAC in this swine model. Spatial drug distribution was heterogeneous with both technics, with hotspots closed to the drug delivery sites. Nevertheless, considering the dose ratio, IP drug uptake yield was better with PIPAC.

Impact of multidisciplinary tumour board in the management of ovarian carcinoma in the first-line setting. Exhaustive analysis from the Rhone-Alpes region.

OBJECTIVE: Epithelial ovarian cancer (EOC) is a poor prognosis disease partly linked to diagnosis at an advanced stage. The quality of care management is a factor that needs to be explored, more specifically optimal organisation of first-line treatment. METHODS: A retrospective study, dealing with all patients diagnosed within the Rhone-Alpes region with initial diagnosis EOC in 2012, was performed. The aim was to describe the impact of multidisciplinary tumour boards (MTB) in the organisation of care and the consequence on the patient's outcomes. RESULTS: 271 EOC were analysed. 206 patients had an advanced EOC. Median progression-free survival (PFS) is 17.8 months (CI95%, 14.6-21.2) for AOC. 157 patients (57.9%) had a front-line surgery versus 114 patients (42.1%) interval debulking surgery. PFS for AOC patients with no residual disease is 24.3 months compared with 15.3 months for patients with residual disease (p = .01). No macroscopic residual disease is more frequent in the patients discussed before surgery in MTB compared with patients not submitted before surgery (73% vs. 56.2%, p < .001). CONCLUSION: These results highlight the heterogeneity of medical practices in terms of front-line surgery versus interval surgery, in the administration of neoadjuvant chemotherapy and in the setting of MTB discussion.

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

Pressurised intraperitoneal aerosol chemotherapy (PIPAC) was introduced as a new treatment for patients with peritoneal metastases in November, 2011. Reports of its feasibility, tolerance, and efficacy have encouraged centres worldwide to adopt PIPAC as a novel drug delivery technique. In this Review, we detail the technique and rationale of PIPAC and critically assess its evidence and potential indications. A systematic search was done to identify all relevant literature on PIPAC published between Jan 1, 2011, and Jan 31, 2019. A total of 106 articles or reports on PIPAC were identified, and 45 clinical studies on 1810 PIPAC procedures in 838 patients were included for analysis. Repeated PIPAC delivery was feasible in 64% of patients with few intraoperative and postoperative surgical complications (3% for each in prospective studies). Adverse events (Common Terminology Criteria for Adverse Events greater than grade 2) occurred after 12-15% of procedures, and commonly included bowel obstruction, bleeding, and abdominal pain. Repeated PIPAC did not have a negative effect on quality of life. Using PIPAC, an objective clinical response of 62-88% was reported for patients with ovarian cancer (median survival of 11-14 months), 50-91% for gastric cancer (median survival of 8-15 months), 71-86% for colorectal cancer (median survival of 16 months), and 67-75% (median survival of 27 months) for peritoneal mesothelioma. From our findings, PIPAC has been shown to be feasible and safe. Data on objective response and quality of life were encouraging. Therefore, PIPAC can be considered as a treatment option for refractory, isolated peritoneal metastasis of various origins. However, its use in further indications needs to be validated by prospective studies.

Peritoneal Carcinomatosis of Rare Ovarian Origin Treated by Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: A Multi-Institutional Cohort from PSOGI and BIG-RENAPE.

PURPOSE: Ovarian cancer is the most common deadly cancer of gynecologic origin. Patients often are diagnosed at advanced stage with peritoneal metastasis. There are many rare histologies of ovarian cancer; some have outcomes worse than serous ovarian cancer. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) can be considered for patients with recurrence. This study was designed to assess the impact of CRS and HIPEC on survival of patient with peritoneal metastasis from rare ovarian malignancy. METHODS: A prospective, multicentric, international database was retrospectively searched to identify all patients with rare ovarian tumor (mucinous, clear cells, endometrioid, small cell hypercalcemic, and other) and peritoneal metastasis who underwent CRS and HIPEC through the Peritoneal Surface Oncology Group International (PSOGI) and BIG-RENAPE working group. The postoperative complications, long-term results, and principal prognostic factors were analyzed. RESULTS: The analysis included 210 patients with a median follow-up of 43.5 months. Median overall survival (OS) was 69.3 months, and the 5-year OS was 57.7%. For mucinous tumors, median OS and DFS were not reached at 5 years. For granulosa tumors, median overall survival was not reached at 5 years, and median DFS was 34.6 months. Teratoma or germinal tumor showed median overall survival and DFS that were not reached at 5 years. Differences in OS were not statistically significant between histologies (p = 0.383), whereas differences in DFS were (p < 0.001). CONCLUSIONS: CRS and HIPEC may increases long-term survival in selected patients with peritoneal metastasis from rare ovarian tumors especially in mucinous, granulosa, or teratoma histological subtypes.