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.

Eliminating the need for preoperative intravenous hyperhydration: Sodium thiosulfate as nephrotoxicity prevention in HIPEC-treated patients - A retrospective analysis.

BACKGROUND: Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) is an effective treatment for peritoneal metastases. However, HIPEC with cisplatin is associated with renal toxicity. Sodium thiosulfate (ST) has been shown to prevent cisplatin-induced toxicity. METHODS: A retrospective, single-center analysis of patients treated curatively for peritoneal surface malignancy, who underwent cytoreductive surgery with cisplatin-based HIPEC between 2015 and 2020. Patients were categorized into three groups based on the management of cisplatin-induced renal toxicity: preoperative hyperhydration alone (PHH), preoperative hyperhydration with ST (PHH + ST), and ST alone. Renal function and complications, in terms of Acute (AKI) and chronic kidney injury (CKI), were monitored and analyzed during 3 postoperative months. RESULTS: This study included 220 consecutive patients. Mean serum creatinine levels were 95, 57 and 61 mmol/L, for PHH, PHH + ST and ST groups, respectively (p < 0.001). Glomerular Filtration Rate (GFR) were 96, 94 and 78 ml/min/1.73 m2, respectively (p < 0.001). AKI and CKI are respectively for PHH, PHH + ST and ST groups were 21 % (n = 46), 1 % (n = 2) and 0 % vs 19 % (n = 42), 0 % and 0 % (p < 0.001), for pairwise analysis did not show any difference between PHH + ST and ST alone combination, regarding nephrological outcomes. All patients were followed 3 months postoperatively. CONCLUSION: There is no need for preoperative hyperhydration when sodium-thiosulfate is used to prevent cisplatin-induced nephrotoxicity in patients undergoing cytoreductive surgery with HIPEC. These findings have implications for improving and simplifying the management of patients with peritoneal metastases undergoing HIPEC with cisplatin.

Metastatic Colorectal Cancer Treated with Combined Liver Resection, Cytoreductive Surgery, and Hyperthermic Intraperitoneal Chemotherapy (HIPEC): Predictive Factors for Early Recurrence.

BACKGROUND: Selection of colorectal cancer patients with concomitant peritoneal (PM) and liver metastases (LM) for radical treatment with cytoreductive surgery (CRS), including liver resection and hyperthermic intraperitoneal chemotherapy (HIPEC), needs improvement. This retrospective, monocentric study was designed to evaluate the predictive factors for early recurrence, disease-free survival (DFS), and overall survival (OS) in such patients treated in a referral center. METHODS: Consecutive colorectal cancer patients with concomitant LM and PM treated with curative intent with perioperative systemic chemotherapy, simultaneous complete CRS, liver resection, and HIPEC in 2011-2022 were included. Clinical, radiological (before and after preoperative chemotherapy), surgical, and pathological data were investigated, along with long-term oncologic outcomes. A multivariate analysis was performed to identify predictive factors associated with early recurrence (diagnosed <6 months after surgery), DFS, and OS. RESULTS: Of more than 61 patients included, 31 (47.1%) had pT4 and 27 (40.9%) had pN2 primary tumors. Before preoperative chemotherapy, the median number of LM was 2 (1-4). The median surgical PCI (peritoneal carcinomatosis index) was 3 (5-8.5). The median DFS and OS were 8.15 (95% confidence interval [CI] 5.5-10.1) and 34.1 months (95% CI 28.1-53.5), respectively. In multivariate analysis, pT4 (odds ratio [OR] = 4.14 [1.2-16.78], p = 0.032]) and pN2 (OR = 3.7 [1.08-13.86], p = 0.042) status were independently associated with an early recurrence, whereas retroperitoneal lymph node metastasis (hazard ratio [HR] = 39 [8.67-175.44], p < 0.001) was independently associated with poor OS. CONCLUSIONS: In colorectal cancer patients with concomitant PM and LM, an advanced primary tumor (pT4 and/or pN2) was associated with a higher risk of early recurrence following a radical multimodal treatment, whereas RLN metastases was strongly detrimental for OS.

Negative-Pressure Wound Therapy for Open Abdomen in Surgical Reintervention after Curative Surgery of Peritoneal Malignancy Increases the Risk of Recurrence.

OBJECTIVE: Negative-pressure wound therapy for open abdomen (NPWTOA) helps reduce the risk of abdominal compartment syndrome. However, the risk of recurrence of cancer is unclear when NPWTOA is applied after oncologic resection. The aim of this study was to evaluate the effects of NPWTOA used for major complications on patients treated with cytoreductive surgery for peritoneal malignancy (PM). METHODS: All patients who underwent an NPWTOA after potentially curative surgery of PM in a single institution were included. These patients were pair matched 1:3 on the Peritoneal Cancer Index, completeness of cytoreduction using a scoring index, and PM origin with patients who underwent surgical reintervention without NPWTOA after curative surgery of PM. Survival among the two groups was compared using the Kaplan-Meier method. RESULTS: Between 2011 and 2017, among 719 curative surgeries for PM, 13 patients underwent an NPWTOA after surgical reintervention. Researchers paired 9 of these patients to 27 others without NPWTOA after surgical reintervention. Median overall survival was 4.8 and 35 months (P = .391), and median disease-free survival was 4.0 and 13.9 months (P = .022) for the NPWTOA and non-NPWTOA groups, respectively. CONCLUSIONS: The use of the NPWTOA during surgical reintervention after curative surgery for PM may increase the risk of early recurrence.

2022 PSOGI Consensus on HIPEC Regimens for Peritoneal Malignancies: Diffuse Malignant Peritoneal Mesothelioma.

BACKGROUND: Diffuse malignant peritoneal mesothelioma (DMPM) is a rare and aggressive primary peritoneal disease, with recommended treatment, in eligible patients, of a combination of complete cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). As treatment is multimodal, there is a wide heterogeneity of HIPEC protocols precluding clear comparisons. Standardization at an international level is required. METHODS: The Peritoneal Surface Oncology Group International (PSOGI) designated a steering committee to produce consensus recommendations for HIPEC regimens, adapted to each etiology. The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology was used, based on a systematic review focused on main outcomes related to HIPEC regimens in DMPM patients and on the patient, intervention, comparator, and outcome (PICO) method to elaborate main questions. An opinion survey was added. Furthermore, a Delphi process was performed with voting from a panel of international experts. RESULTS: Eleven questions were elaborated, including two for future research requirements and three to assess the HIPEC regimen preference of the panel. The level of evidence underlying questions was globally low. Overall, 75 (86%) and 67 (77%) of the 87 invited experts completed the vote at the first and second round, respectively. HIPEC following complete CRS was strongly supported by 88% of voters with no need to plan comparative studies with CRS alone for 61.2% of voters. Bi-drug regimens appeared to be preferred to mono-drug ones and cisplatin was globally favored. The opinion survey confirmed the combination of cisplatin and doxorubicin as the recommended regimen. CONCLUSION: International consensus confirmed the indication of HIPEC following complete CRS in DMPM patients and recommended cisplatin-doxorubicin as the first-line HIPEC regimen.

Post-operative weight loss affects 3-year survival in patients with gastric adenocarcinoma after gastrectomy and hyperthermic intraperitoneal chemotherapy.

INTRODUCTION: Patients with advanced gastric adenocarcinoma are at high risk of malnutrition. Some patients benefit from total gastrectomy associated with hyperthermic intraperitoneal chemotherapy (HIPEC) with or without cytoreduction surgery (CR) as a curative strategy. The aim of this study was to describe pre- and post-operative nutritional assessments and their impact on survival in these patients. MATERIALS AND METHODS: All patients with advanced gastric adenocarcinoma treated with gastrectomy and HIPEC with or without CR at Lyon University Hospital were retrospectively included from April 2012 to August 2017. Carcinologic data, history of weight, anthropometric measures, nutritional biological markers and CT-scan body composition were collected. RESULTS: 54 patients were included. Malnutrition affected 48.1% before and 64.8% after surgery, and severe malnutrition respectively 11.1% and 20.3%. Pre-operative sarcopenia diagnosed by CT scan was found in 40.7% of the patients while 81.1% of the sarcopenic patients had a normal or high body mass index. A loss of ⩾ 20% of usual weight on discharge was a pejorative factor of survival at 3 years of follow-up (p = 0.0470). Only 14.8% of the patients continued artificial nutrition following discharge but artificial nutrition was resumed in 30.4% of the patients within 4 months after discharge owing to weight loss. CONCLUSIONS: Patients with advanced gastric adenocarcinoma undergoing gastrectomy and HIPEC with or without CR are at high risk of malnutrition. Post-operative weight loss has a pejorative impact on outcome. These patients should be systematically screened for malnutrition with early interventionist nutritional care and close nutritional follow-up.

Peritoneal metastasis of advanced epithelial ovarian carcinoma treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: A retrospective international multicentric data analysis.

INTRODUCTION: The purpose of our study was to evaluate outcome data after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with peritoneal metastasis originating from advanced epithelial ovarian carcinoma (PMOC). PATIENTS AND METHODS: A retrospective international multi-institutional registry was established through collaborative efforts of participating units affiliated with the Peritoneal Surface Oncology Group. RESULTS: One thousand four hundred and ninety-one patients from 11 specialized units underwent CRS and HIPEC that of those 326 (21.9%) upfront surgeries, 504 (33.8%) interval surgery, and 661(44.3%) recurrent cases. Complete Cytoreduction(CC0/1) was achieved in 1213 patients (81.3%). Treatment -related mortality was 0.8%, major operative complications (Grades 3-5) was 25.1%. Factors associated with major operative complications include prior surgical score (PSS for recurrent cases; RC) PSS>2,p = 0.000), PCI(≤15, >15 cut-off level; p ≤ 0.000), completeness of cytoreduction (CC, p=0.000), high CA125 levels (>25 mg/dl), presence of ascites, high CRP (>5 mg/dl) levels and low albumin levels (below to 2.5 mg/dl) (p ≤ 0.05). The median survival was 58 months in upfront surgery(UFS), 60 months in interval surgery(IS), and 42 months in RC. The overall survival for five years was 45% for UFS, 37% for IS, 28% for RC cases. CCscore (p = 0.000), CA125, CRP and albumin levels (p ≤ 0.05) were predictors for progression free survival. PCI(p ≤ 0.000), major postoperative complications (p = 0.004), incomplete CRS(CC2/3)(p < 0.001), prior chemotherapy (hazard ratio [HR], 3-8; p < 0.001) and PSS>2 for RC were independent predictors of poor overall survival. CONCLUSION: The combined treatment strategy for PMOC may be performed safely with acceptable morbidity and mortality in the specialized units.

Influence of Extraperitoneal Metastases on the Curative-Intent Management of Colorectal Peritoneal Metastases.

BACKGROUND: Selected patients with colorectal cancer peritoneal metastasis (CRPM) and extraperitoneal disease could be treated radically with a multimodal approach combining complete cytoreductive surgery, thermoablation, radiotherapy, and systemic and intraperitoneal chemotherapy. The impact of extraperitoneal metastatic sites (EPMS) in this setting remains unclear. PATIENTS AND METHODS: Patients with CRPM undergoing complete cytoreduction in 2005-2018 were grouped in: peritoneal disease only (PDO), one EPMS (1 + EPMS), two or more EPMS (2 + EPMS). A retrospective analysis compared overall survival (OS) and postoperative outcomes. RESULTS: Of 433 patients, 109 had 1 + EPMS and 31 had 2 + EPMS. Overall, 101 patients had liver metastasis, 19 lung metastasis, and 30 retroperitoneal lymph node (RLN) invasion. The median OS was 56.9 months. There was no significant OS difference between PDO and 1 + EPMS groups (64.6 and 57.9 months, respectively), whereas OS was lower in the 2 + EPMS group (29.4 months, p = 0.005). In multivariate analysis, 2 + EPMS [hazard ratio (HR) 2.86, 95% confidence interval (CI) 1.33-6.12, p = 0.007], Sugarbaker's Peritoneal Carcinomatosis Index (PCI) > 15 (HR 3.86, 95% CI 2.04-7.32, p < 0.001), poorly differentiated tumors (HR 2.62, 95% CI 1.21-5.66, p = 0.015), and BRAF mutation (HR 2.10, 95% CI 1.11-3.99, p = 0.024) were independent poor prognostic factors, while adjuvant chemotherapy was beneficial (HR 0.33, 95% CI 0.20-0.56, p < 0.001). Patients with liver resection did not show higher severe complication rates. CONCLUSION: In patients with CRPM selected for a radical surgical approach, limited extraperitoneal disease involving one site, notably the liver, does not seem to significantly impair postoperative results. RLN invasion appeared as a poor prognostic factor in this population.

Comparison of Neoadjuvant Systemic Chemotherapy Protocols for the Curative-Intent Management of Peritoneal Metastases from Colorectal Cancer, Regarding Morphological Response, Pathological Response, and Long-Term Outcomes: A Retrospective Study.

BACKGROUND: Selected patients with colorectal cancer peritoneal metastases (CRPM) could be offered a curative-intent strategy based on complete cytoreductive surgery (CRS), potentially combined with hyperthermic intraperitoneal chemotherapy (HIPEC) and perioperative systemic chemotherapy. The impact of different neoadjuvant systemic chemotherapy (NACT) regimens remains unclear due to a lack of comparative data. METHODS: Consecutive CRPM patients from a monocentric database who were treated with complete CRS after single-line NACT were included in this study. Chemotherapy regimens were tailored as a doublet drug (FOLFOX/FOLFIRI) with/without targeted therapy (anti-epidermal growth factor receptor/bevacizumab) and triplet-drug combination (FOLFIRINOX). Morphological response (MR) was assessed using the Response Evaluation Criteria in Solid Tumors criteria, and pathological response (PR) was assessed using the Peritoneal Regression Grading Score (PRGS). Long-term oncologic outcomes were compared. RESULTS: The cohort comprised 388 patients, including 127, 202, and 59 patients in the doublet, doublet + targeted, and triplet groups, respectively. MR rates were higher in the triplet (68.0%) and doublet + targeted groups (64.2%) when compared with the doublet group (42.4%, p = 0.003). Complete and major PRs were observed in 13.6% and 32.0% of patients, respectively. Higher MR rates were observed after doublet + targeted or triplet regimens, while no difference was observed for PR rates. In multivariate analysis, FOLFIRINOX was independently associated with better overall survival (hazard ratio 0.49, 95% confidence interval 0.25-0.96; p = 0.037). FOLFIRINOX also resulted in a higher rate of severe postoperative complications. CONCLUSIONS: In this retrospective study, a FOLFIRINOX regimen as NACT seemed to result in better long-term outcomes for CRPM patients after complete CRS/HIPEC, although with higher morbidity. Prospective studies are needed, including groups without NACT and those with FOLFIRINOX + bevacizumab.

Multicystic peritoneal mesothelioma treated with cytoreductive surgery followed or not by hyperthermic intraperitoneal chemotherapy: results from a large multicentric cohort.

BACKGROUND: Multicystic peritoneal mesothelioma (MCPM) is a rare, slowly growing, condition prone to recur after surgery. The role of hyperthermic intraperitoneal chemotherapy (HIPEC) added to complete cytoreductive surgery (CRS) remains controversial and difficult to assess. As patients are mostly reproductive age women, surgical approach, and fertility considerations are important aspects of the management. This observational retrospective review aimed to accurate treatment strategy reflections. METHODS: The RENAPE database (French expert centers network) was analyzed over a 1999-2019 period. MCPM patients treated with CRS were included. A special focus on HIPEC, mini-invasive approach, and fertility considerations was performed. RESULTS: Overall 60 patients (50 women) were included with a median PCI of 10 (4-14) allowing 97% of complete surgery, followed by HIPEC in 82% of patients. A quarter of patients had a laparoscopic approach. Twelve patients (20%) recurred with a 3-year recurrence free survival of 84.2% (95% confidence interval 74.7-95.0). The hazard of recurrence was numerically reduced among patients receiving HIPEC, however, not statistically significant (hazard ratio 0.41, 0.12-1.42, p = 0.200). A severe post-operative adverse event occurred in 22% of patients with five patients submitted to a subsequent reoperation. Among four patients with a childbearing desire, three were successful (two had a laparoscopic-CRS-HIPEC and one a conventional CRS without HIPEC). CONCLUSION: MCPM patients treatment should aim at a complete CRS. The intraoperative treatment options as laparoscopic approach, fertility function sparing and HIPEC should be discussed in expert centers to propose the most appropriate strategy.

The Combination of Bromelain and Acetylcysteine (BromAc) Synergistically Inactivates SARS-CoV-2.

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection is the cause of a worldwide pandemic, currently with limited therapeutic options. The spike glycoprotein and envelope protein of SARS-CoV-2, containing disulfide bridges for stabilization, represent an attractive target as they are essential for binding to the ACE2 receptor in host cells present in the nasal mucosa. Bromelain and Acetylcysteine (BromAc) has synergistic action against glycoproteins by breakage of glycosidic linkages and disulfide bonds. We sought to determine the effect of BromAc on the spike and envelope proteins and its potential to reduce infectivity in host cells. Recombinant spike and envelope SARS-CoV-2 proteins were disrupted by BromAc. Spike and envelope protein disulfide bonds were reduced by Acetylcysteine. In in vitro whole virus culture of both wild-type and spike mutants, SARS-CoV-2 demonstrated a concentration-dependent inactivation from BromAc treatment but not from single agents. Clinical testing through nasal administration in patients with early SARS-CoV-2 infection is imminent.

Site of Recurrence and Survival After Surgery for Colorectal Peritoneal Metastasis.

BACKGROUND: Multimodal treatment, including systemic treatment and surgery, improved the prognosis of peritoneal metastasis (PM). Despite all efforts, recurrence rates remain high, and little data are available about clinical behavior or molecular patterns of PM in comparison to hematogenous metastasis. Here, we aimed to analyze recurrence patterns after multimodal treatment for PM from colorectal cancer. METHODS: Patients with colorectal PM undergoing multimodal treatment including systemic chemotherapy and cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) between 2005 and 2017 at 4 centers were analyzed retrospectively. RESULTS: A total of 505 patients undergoing CRS/HIPEC were analyzed. Of the patients, 82.1% received preoperative chemotherapy. Median peritoneal cancer index was 6 (interquartile range = 3-11). Median disease-free and overall survival was 12 (95% confidence interval [CI] = 11 to 14) months and 51 (95% CI = 43 to 62) months, respectively. Disease recurred in 361 (71.5%) patients, presenting as isolated peritoneal recurrence in 24.6%, isolated hematogenous recurrence in 28.3%, and mixed recurrence in 13.9% of patients. Recurrence to the peritoneum was associated with an impaired time from recurrence to death of 21 (95% CI = 18 to 31) months for isolated peritoneal and 22 (95% CI = 16 to 30) months for mixed recurrence, compared with 43 (95% CI = 31 to >121) months for hematogenous recurrence (hazard ratio [HR] = 1.79, 95% CI = 1.27 to 2.53; P = .001; and HR = 2.44, 95% CI = 1.61 to 3.79; P < .001). On multiple logistic regression analysis, RAS mutational status (odds ratio [OR] = 2.42, 95% CI = 1.11 to 5.47; P = .03) and positive nodal stage of the primary (OR = 3.88, 95% CI = 1.40 to 11.86; P = .01) were identified as predictive factors for peritoneal recurrence. CONCLUSIONS: This study highlights the heterogeneity of peritoneal metastasis in patients with colorectal cancer. Recurrent peritoneal metastasis after radical treatment represents a more aggressive subset of metastatic colorectal cancer.

Bromelain and acetylcysteine (BromAc®) alone and in combination with gemcitabine inhibit subcutaneous deposits of pancreatic cancer after intraperitoneal injection.

Gemcitabine (GEM) is commonly chosen for treating pancreatic cancer. However, its use is limited by toxicity. Earlier in vitro studies with GEM in combination with Bromelain (Brom) and Acetylcysteine (Ac) indicated a substantial reduction in IC50. In this study, immunocytochemistry and Western blot were used to explore the mechanistic effects of Brom and Ac (BromAc®) in vitro. Then, we explored the efficacy and safety of BromAc® only and with GEM in a pancreatic cancer model in vivo. Immunocytochemistry results revealed a reduction in both MUC1 and MUC4 post-treatment. There was a decrease in VEGF, MMP-9, NF-κß and cleavage of PARP. There was also a decrease in the cell cycle regulators Cyclin B and D as well as TGF-ß and the anti-apoptotic Bcl-2. In vivo, the low and high doses of BromAc® alone and with chemotherapy agents were safe. A very significant reduction in pancreatic tumour volume, weight, and ki67 were seen with BromAc® therapy and was equal to treatment with GEM alone and better than treatment with 5-FU. In addition, tumour density was significantly reduced by BromAc®. In conclusion, the anticancer effect of BromAc® is probably related to its mucin depletion activity as well as its effect on proteins involved in cell cycle arrest, apoptosis and modulation of the tumour microenvironment. The in vivo results are encouraging and are considered the first evidence of the efficacy of BromAc® in pancreatic cancer. These results also provide some mechanistic leads of BromAc®.

Clinical and Radiologic Predictors of a Pathologic Complete Response to Neoadjuvant Chemotherapy (NACT) in Patients Undergoing Cytoreductive Surgery for Colorectal Peritoneal Metastases: Results of a Prospective Multi-center Study.

BACKGROUND: Patients undergoing cytoreductive surgery for colorectal peritoneal metastases who have a pathologic complete response (pCR) to neoadjuvant chemotherapy experience a significantly longer survival than those with residual disease. This response is known only after surgery. This study aimed to examine clinical and radiologic predictors of a pCR. METHODS: From July 2018 to December 2019, the study prospectively enrolled 120 patients. The clinical and radiologic findings were compared between patients with and without a pCR. A protocol for pathologic evaluation was followed. RESULTS: A pCR was observed in 34 patients (28.3%). Receiver operating characteristic (ROC) curves showed that patients with a surgical Peritoneal Cancer Index (sPCI) of 3 or lower had an 80% probability of experiencing a pCR, and that patients with a radiologic PCI (rPCI) of 2 or lower had a 70% probability of experiencing a pCR. A pCR was correctly predicted for 47% of the patients by imaging and for 44.4% of the patients by surgical evaluation. The site of primary tumor, the timing of peritoneal metastasis (PM), histology, tumor marker positivity, and mutations in known poor prognostic genes (KRAS) did not differ between the patients with and those without pCR. The primary tumor showed residual disease in 23.5% and regional nodes in 26.4% of the patients with pCR. CONCLUSIONS: The rPCI and sPCI concurred with a pCR in less than 50% of the patients. The patients with a lower PCI had greater concordance. An sPCI of 3 or lower was predictive of a pCR in 80% of the patients. The impact of KRAS mutations on pCR should be evaluated in a larger series. The predictors of pCR and response to systemic chemotherapy should be incorporated in prognostic scores used to select patients for surgery.

Multicystic and diffuse malignant peritoneal mesothelioma in children.

BACKGROUND: Malignant and multicystic peritoneal mesotheliomas are extremely rare tumors in children, developing from mesothelial cells. No specific guidelines are available at this age. METHODS: We performed a retrospective analysis of all identified children (< 18-year-old) treated in France from 1987 to 2017 for a diffuse malignant peritoneal mesothelioma (DMPM) or a multicystic peritoneal mesothelioma (MCPM). RESULTS: Fourteen patients (5 males and nine females), aged 2.2 to 17.5 years, were included. The most frequent presenting symptoms were abdominal pain, ascitis, and alteration in the general condition. Eight patients had epithelioid mesothelioma, three had biphasic mesothelioma, and three had MCPM. Eight patients with DMPM diagnosis received cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Among them, six patients had neoadjuvant systemic chemotherapy, one patient, post-operative chemotherapy, and one patient CRS and HIPEC only. Three patients received only systemic chemotherapy. All patients with MCPM had only surgery. After a median follow-up of seven years (2-15), six patients (6/11; one death) with DMPM and two patients (two/three) with MCPM had a local and distant recurrences. CONCLUSION: Peritoneal mesothelioma in children is a rare condition with difficult diagnosis and high risk of recurrence. Worldwide interdisciplinary collaboration and networking are mandatory to help diagnosis and provide harmonious treatment guidelines.

Cytoreductive Surgery With or Without Hyperthermic Intraperitoneal Chemotherapy for Gastric Cancer With Peritoneal Metastases (CYTO-CHIP study): A Propensity Score Analysis.

PURPOSE: Gastric cancer (GC) with peritoneal metastases (PMs) is a poor prognostic evolution. Cytoreductive surgery (CRS) yields promising results, but the impact of hyperthermic intraperitoneal chemotherapy (HIPEC) remains controversial. Here we aimed to compare outcomes between CRS-HIPEC versus CRS alone (CRSa) among patients with PMs from GC. PATIENTS AND METHODS: From prospective databases, we identified 277 patients with PMs from GC who were treated with complete CRS with curative intent (no residual nodules > 2.5 mm) at 19 French centers from 1989 to 2014. Of these patients, 180 underwent CRS-HIPEC and 97 CRSa. Tumor burden was assessed using the peritoneal cancer index. A Cox proportional hazards regression model with inverse probability of treatment weighting (IPTW) based on propensity score was used to assess the effect of HIPEC and account for confounding factors. RESULTS: After IPTW adjustment, the groups were similar, except that median peritoneal cancer index remained higher in the CRS-HIPEC group (6 v 2; P = .003). CRS-HIPEC improved overall survival (OS) in both crude and IPTW models. Upon IPTW analysis, in CRS-HIPEC and CRSa groups, median OS was 18.8 versus 12.1 months, 3- and 5-year OS rates were 26.21% and 19.87% versus 10.82% and 6.43% (adjusted hazard ratio, 0.60; 95% CI, 0.42 to 0.86; P = .005), and 3- and 5-year recurrence-free survival rates were 20.40% and 17.05% versus 5.87% and 3.76% (P = .001), respectively; the groups did not differ regarding 90-day mortality (7.4% v 10.1%, respectively; P = .820) or major complication rate (53.7% v 55.3%, respectively; P = .496). CONCLUSION: Compared with CRSa, CRS-HIPEC improved OS and recurrence-free survival, without additional morbidity or mortality. When complete CRS is possible, CRS-HIPEC may be considered a valuable therapy for strictly selected patients with limited PMs from GC.

Well-Differentiated Papillary Mesothelioma of the Peritoneum: A Retrospective Study from the RENAPE Observational Registry.

BACKGROUND: Well-differentiated papillary mesothelioma of the peritoneum (WDPMP) is a rare entity. Questions regarding management are still being debated as no more than 50 cases have been reported in the literature. OBJECTIVE: We aimed to analyze the clinical, therapeutic, and prognostic data of patients with WDPMP from the RENAPE observational registry. PATIENTS AND METHODS: All patients diagnosed with WDPMP and prospectively included in the RENAPE national registry between 2010 and 2018 were also included in our study. Expert pathologists from the RENA-PATH group confirmed all cases. All clinical, therapeutic, postoperative, and prognostic data were extracted and analyzed. RESULTS: We report on 56 patients with a mean age of 52 years (range 21-74). WDPMP was incidentally diagnosed during imaging or surgery in 16% and 36% of patients, respectively, and an association with synchronous malignancy was found in 18% of patients. Nine lesions showed discrete signs of fatty invasion. The median Peritoneal Cancer Index was 11 (range 0-33). Eleven patients were treated with definitive excision, 4 were treated with cytoreductive surgery (CRS) only, 37 were treated with CRS and hyperthermic intraperitoneal chemotherapy (HIPEC), and 2 were treated with CRS plus HIPEC plus early postoperative intraperitoneal chemotherapy. CRS was considered to be complete in 90% of cases. One patient died postoperatively and 16 patients (31%) faced postoperative complications. The median disease-free survival was 144 months; Four patients relapsed, with a median period of 27 months. No prognostic factors could be identified. CONCLUSIONS: Our analysis confirms the favorable prognosis of WDPMP. CRS and HIPEC could be a therapeutic option for diffuse, symptomatic, and/or recurrent disease.

Well differentiated papillary peritoneal mesothelioma treated by cytoreduction and hyperthermic intraperitoneal chemotherapy-the experience of the PSOGI registry.

BACKGROUND: Well differentiated papillary peritoneal mesothelioma (WDPPM) is a rare variant of mesothelioma which affects mainly women in the reproductive age. The disease may present multifocally and recur after primary resection. Our aim was to describe the outcomes of cytoreduction (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in this disease. METHODS: Patients with histological diagnosis of WDPPM were retrieved from the PSOGI registry. Demographical and clinical data were extracted as well as outcomes data (overall survival (OS) and recurrence free survival (RFS)). RESULTS: We analyzed 45 patients for whom complete data was available. The majority of patients were women (n = 33, 73%) with a median age of 44 years. Preoperative chemotherapy (CT) was administered in 8 patients (18%). Median peritoneal carcinomatosis index was 9 (1-30), and complete cytoreduction was achieved in 69% of patients. There was one case (2%) of postoperative mortality, and 24% rate of severe morbidity. Overall, there were 4 deaths and 5 years OS was 80%. 8 patients (18%) had disease recurrence, all within 5 years from operation. On univariate analysis preoperative CT, high PCI and severe morbidity were associated with reduced RFS. On multivariate analysis, only preoperative CT (HR = 32.6, 95% CI: 2.39-446.2, p = 0.009) and high PCI (HR = 21.7, 95% CI: 1.11-425.7, p = 0.04) remained significant risk factors. CONCLUSIONS: WDPPM can be a lethal disease with substantial recurrence even after aggressive treatment. Patients presenting with extensive disease or disease recurrence after surgical excision are at increased risk for relapse. CRS + HIPEC can be safely applied to WDPPM in specialized centers.