Update on gene fusions and the emerging clinicopathological landscape of peritoneal and pleural mesotheliomas and other neoplasms.

BACKGROUND: Mesothelioma is a rare and aggressive malignant neoplasm arising from mesothelial cells, which occasionally manifests recurrent fusions. EWSR1/FUS-CREB, YY1, MAP3K8, NR4A3, and ALK-rearranged proliferations have been reported in limited series with no clear histological or clinical correlations, limiting clinicians' ability to assess prognosis and integrate these new entities into therapeutic decisions. The aim of this study was to better characterize these rearranged proliferations histologically, molecularly, and clinically. METHODS: Clinical, pathological, and comprehensive transcriptome and mutation data were collected for each case. RESULTS: A total of 41 tumors were included, encompassing 7 ALK, 10 MAP3K8, 4 NR4A3, 8 ESWR1/FUS::ATF1, 8 EWSR1::YY1, and 4 SUFU-fused cases. We found a female predominance, except for cases harboring NR4A3 and SUFU; and most patients were around 60 years of age, but those harboring ALK or EWSR1/FUS::ATF1 gene fusions were younger. Each group exhibited distinct histological, immunohistochemical, molecular features, and oncological courses. Specifically, MAP3K8 and ALK presented PAX8+ papillary proliferations, ESWR1/FUS::ATF1 and EWSR1::YY1 displayed angiomatoid fibrous histiocytoma-like patterns, while SUFU showcased 'tissue culture'-like spindle cell proliferation. Poor prognosis factors were the pleural site, male sex, Ki67 ≥10%, and ESWR1/FUS::ATF1 or SUFU gene fusions. CONCLUSIONS: This study significantly broadens the spectrum of mesothelial tumors associated with fusions, offering insight into novel epithelioid (mesothelial) proliferations with distinctive histological appearances, molecular profiles, and prognoses to guide adapted treatments for patients.

External multicentre validation of pseudomyxoma peritonei PSOGI-Ki67 classification.

BACKGROUND: Pseudomyxoma peritonei (PMP) is a rare malignant disease. Adding of the Ki67 proliferation index to the PSOGI PMP classification provided two different subcategories of the extensive HG-PMP group (HG-PMP ≤15% and HG-PMP >15%) with different survival in a previous unicentric study. This study aims to carry out an external and multicentre validation of this new proposed classification. METHOD: It was a prospective analysis of samples from a historical and international cohort of patients. A representative area with higher cellular density was used to determine the Ki67%. The Ki67 proliferation index (%) was determined in all the HG-PMP patients. A Cox proportional hazard models and multivariable COX models were used. The Kaplan-Meier method and the two-tailed log-rank test were used to analyse the effect of different PSOGI-Ki67 categories on OS and DFS. Its predictive accuracy was analysed using Harrel's C-index and the ROC curve. The calibration was performed using the calibration plots matching. RESULTS: After exclusions, 349 patients were available for analysis. The 5-years OS were 86% for LG-PMP, 59% for HG-PMP≤15, 38% for HG-PMP>15 and 42% for SRC-PMP (p = 0.0001). The 5-years DFS were 49% for LG-PMP, 35% for HG-PMP≤15, 16% for HG-PMP>15 and 18% SRC-PMP (p = 0.0001). The discrimination capability of PSOGI-Ki67 was validated. CONCLUSION: the PSOGI-Ki67 classification discriminates and predicts the OS and DFS in patients with PMP dividing the HG-PMP category into two well-defined sub-categories. The Ki67 proliferation index should be incorporated routinely in the pathology report for these patients.

The Delphi and GRADE methodology used in the PSOGI 2018 consensus statement on Pseudomyxoma Peritonei and Peritoneal Mesothelioma.

Pseudomyxoma Peritonei (PMP) and Peritoneal Mesothelioma (PM) are both rare peritoneal malignancies. Currently, affected patients may be treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy offering long-term survival or even cure in selected patients. However, many issues regarding the optimal treatment strategy are currently under debate. To aid physicians involved in the treatment of these patients in clinical decision making, the PSOGI executive committee proposed to create a consensus statement on PMP and PM. This manuscript describes the methodology of the consensus process. The Delphi technique is a reliable method for attaining consensus on a topic that lacks scientific evidence through multiple voting rounds which feeds back responses to the participants in between rounds. The GRADE system provides a structured framework for presenting and grading the available evidence. Separate questionnaires were created for PMP and PM and sent during two voting rounds to 80 and 38 experts, respectively. A consensus threshold of 51.0% was chosen. After the second round, consensus was reached on 92.9%-100.0% of the questions. The results were presented and discussed in the plenary session at the PSOGI 2018 international meeting in Paris. A third round for the remaining issues is currently in progress. In conclusion, using the Delphi technique and GRADE methodology, consensus was reached in many issues regarding the treatment of PM and PMP amongst an international panel of experts. The main results will be published in the near future.

Appendiceal tumours and pseudomyxoma peritonei: Literature review with PSOGI/EURACAN clinical practice guidelines for diagnosis and treatment.

Pseudomyxoma Peritonei (PMP) is a rare peritoneal malignancy, most commonly originating from a perforated epithelial tumour of the appendix. Given its rarity, randomized controlled trials on treatment strategies are lacking, nor likely to be performed in the foreseeable future. However, many questions regarding the management of appendiceal tumours, especially when accompanied by PMP, remain unanswered. This consensus statement was initiated by members of the Peritoneal Surface Oncology Group International (PSOGI) Executive Committee as part of a global advisory role in the management of uncommon peritoneal malignancies. The manuscript concerns an overview and analysis of the literature on mucinous appendiceal tumours with, or without, PMP. Recommendations are provided based on three Delphi voting rounds with GRADE-based questions amongst a panel of 80 worldwide PMP experts.

Prospective correlation of the radiological, surgical and pathological findings in patients undergoing cytoreductive surgery for colorectal peritoneal metastases: implications for the preoperative estimation of the peritoneal cancer index.

AIM: The peritoneal cancer index (PCI) is one of the strongest prognostic factors in patients undergoing cytoreductive surgery (CRS) for colorectal peritoneal metastases. Using pathological evaluation, however, the disease extent differs in a large proportion of patients. Our aim was to study the correlation between the radiological (rPCI), surgical (sPCI) and pathological (pPCI) PCI in order to determine factors affecting the discordance between these indices and their potential therapeutic implications. METHOD: From July 2018 to December 2019, 128 patients were included in this study. The radiological, pathological and surgical findings were compared. A protocol for pathological evaluation was followed at all centres. RESULTS: All patients underwent a CT scan and 102 (79.6%) had a peritoneal MRI. The rPCI was the same as the sPCI in 81 (63.2%) patients and the pPCI in 93 (72.6%). Concordance was significantly lower for moderate-volume (sPCI 13-20) and high-volume (sPCI > 20) disease than for low-volume disease (sPCI 0-12) (P < 0.001 for sPCI; P = 0.001 for pPCI). The accuracy of imaging in predicting presence/absence of disease upon pathological evaluation ranged from 63% to 97% in the different regions of the PCI. The pPCI concurred with the sPCI in 86 (68.8%) patients. Of the nine patients with sPCI > 20, the pPCI was less than 20 in six. CONCLUSION: The rPCI and sPCI both concurred with pPCI in approximately two thirds of patients. Preoperative evaluation should focus on the range in which the sPCI lies and not its absolute value. Radiological evaluation did not overestimate sPCI in any patient with high/moderate-volume disease. The benefit of CRS in patients with a high r/sPCI (> 20) who respond to systemic therapies should be prospectively evaluated.

Sodium thiosulfate protects from renal impairement following hyperthermic intraperitoneal chemotherapy (HIPEC) with Cisplatin.

BACKGROUND: Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has been shown to provide benefits in the management of peritoneal metastasis. Cisplatin (CDDP) is one of the most frequently used drugs for peritoneal infusion. A major restriction is that CDDP causes renal toxicity and acute renal failure, sometimes leading to chronic renal failure. The aim of the present study was to assess the impact of sodium thiosulfate (ST) in preventing renal impairment (RI) following HIPEC with CDDP. METHODS: This prospective study assessed the RI rates for all patients who underwent HIPEC with CDDP during two successive periods: without ST (nST Period; from November 2016 to September 2017) and with ST (ST Period; from October 2017 to March 2018). During the ST Period, patients received an ST infusion at 9 mg/m2 prior to HIPEC and at 12 mg/m2 at the end of the procedure. RI was defined by postoperative serum creatinine >1.6 times elevation of baseline value. The impact of ST treatment was evaluated by comparison of the RI rates between the two periods. RESULTS: During ST Period, none of 38 patients (0%) developed RI versus 11/35 patients (31.4%) during the nST Period (p < .005); 2 of whom required definitive hemodialysis. Baseline characteristics, background circumstances, indications and laboratory parameters before HIPEC were comparable between the two groups, as well as CDDP dose use during HIPEC. CONCLUSION: ST appears to be an effective drug for the prevention of the renal toxicity of CDDP used for HIPEC and should be used for all such procedures.

Treatment of primary and metastatic peritoneal tumors in the Covid-19 pandemic. Proposals for prioritization from the RENAPE and BIG-RENAPE groups.

The Covid-19 pandemic is profoundly changing the organization of healthcare access. This is particularly so for peritoneal neoplastic diseases, for which curative treatment mobilizes substantial personnel, operating room and intensive care resources. The BIG-RENAPE and RENAPE groups have made tentative proposals for prioritizing care provision. A tightening of the usual selection criteria is needed for curative care: young patients with few or no comorbidities and limited peritoneal extension. It is desirable to prioritize disease conditions for which cytoreduction surgery with or without associated hyperthermic intraoperative peritoneal chemotherapy (HIPEC) is the gold-standard treatment, and for which systemic chemotherapy cannot be a temporary or long-term alternative: pseudomyxoma peritonei, resectable malignant peritoneal mesotheliomas, peritoneal metastases of colorectal origin if they are resectable and unresponsive to systemic chemotherapy after up to 12 courses, first-line ovarian carcinomatosis if resectable or in interval surgery after at most six courses of systemic chemotherapy. Addition of HIPEC must be discussed case by case in an expert center. The prioritization of indications must consider local conditions and the phase of the epidemic to allow optimal peri-operative care.

[Treatment of primary and metastatic peritoneal tumors in the Covid-19 pandemic. Proposals for prioritization from the RENAPE and BIG-RENAPE groups]. / Prise en charge des tumeurs primitives et métastatiques du péritoine en période de pandémie CoViD-19. Pistes de réflexion et de priorisation du groupe RENAPE et BIG-RENAPE.

The Covid-19 pandemic is profoundly changing the organization of healthcare access. This is particularly so for peritoneal neoplastic diseases, for which curative treatment mobilizes substantial personnel, operating room and intensive care resources. The BIG-RENAPE and RENAPE groups have made tentative proposals for prioritizing care provision. A tightening of the usual selection criteria is needed for curative care: young patients with few or no comorbidities and limited peritoneal extension. It is desirable to prioritize disease conditions for which cytoreduction surgery with or without associated hyperthermic intraoperative peritoneal chemotherapy (HIPEC) is the gold-standard treatment, and for which systemic chemotherapy cannot be a temporary or long-term alternative: pseudomyxoma peritonei, resectable malignant peritoneal mesotheliomas, peritoneal metastases of colorectal origin if they are resectable and unresponsive to systemic chemotherapy after up to 12 courses, first-line ovarian carcinomatosis if resectable or in interval surgery after at most six courses of systemic chemotherapy. Addition of HIPEC must be discussed case by case in an expert center. The prioritization of indications must consider local conditions and the phase of the epidemic to allow optimal peri-operative care.

Evaluation of a strategy using pretherapeutic fiducial marker placement to avoid missing liver metastases.

Background: Hepatic surgery is appropriate for selected patients with colorectal liver metastases (CRLM). Advances in chemotherapy have led to modification of management, particularly when metastases disappear. Treatment should address all initial CRLM sites based on pretherapeutic cross-sectional imaging. This study aimed to evaluate pretherapeutic fiducial marker placement to optimize CRLM treatment. Methods: This pilot investigation included patients with CRLM who were considered for potentially curative treatment between 2009 and 2016. According to a multidisciplinary team decision, lesions smaller than 25 mm in diameter that were more than 10 mm deep in the hepatic parenchyma and located outside the field of a planned resection were marked. Complication rates and clinicopathological data were analysed. Results: Some 76 metastases were marked in 43 patients among 217 patients with CRLM treated with curative intent. Of these, 23 marked CRLM (30 per cent), with a mean(s.d.) size of 11·0(3·4) mm, disappeared with preoperative chemotherapy. There were four complications associated with marking: two intrahepatic haematomas, one fiducial migration and one misplacement. After a median follow-up of 47·7 (range 18·1-144·9) months, no needle-track seeding was noted. Of four disappearing CRLM that were marked and resected, two presented with persistent active disease. Other missing lesions were treated with thermoablation. Conclusion: Pretherapeutic fiducial marker placement appears useful for the curative management of CRLM.

Surgical management of obstructive left colon cancer at a national level: Results of a multicentre study of the French Surgical Association in 1500 patients.

PURPOSE: Surgical management of obstructive left colon cancer (OLCC) is controversial. The objective is to report on postoperative and oncological outcomes of the different surgical options in patients operated on for OLCC. METHODS: From 2000-2015, 1500 patients were treated for OLCC in centers members of the French Surgical Association. Colonic stent (n=271), supportive care (n=5), palliative derivation (n=4) were excluded. Among 1220 remaining patients, 456 had primary diverting colostomy (PDC), 329 a segmental colectomy (SC), 246 a Hartmann's procedure (HP) and 189 a subtotal colectomy (STC) as first-stage surgery. Perioperative data and oncological outcomes were compared retrospectively. RESULTS: There was no difference between the 4 groups regarding gender, age, BMI and comorbidities. Postoperative mortality and morbidity were 4-27% (PDC), 6-47% (SC), 9-55% (HP), 13-60% (STC), respectively (P=0.005). Among the 431 living patients after PDC, 321 (70%) patients had their primary tumour removed. Cumulative mortality and morbidity favoured PDC (7-39%) and SC (6-40%) compared to HP (1-47%) and STC (13-50%) (P=0.04). At the end of follow-up definitive stoma rates were 39% (HP), 24% (PDC), 10% (SC), and 8% (STC) (P<0.0001). Five-year overall and disease-free survival was: SC (67-55%), PDC (54-48%), HP (54-37%) and STC (48-49%). After multivariate analysis, SC and PDC were associated with better prognosis compared to HP and STC. CONCLUSION: In OLCC, SC and PDC are the two preferred options in patients with good medical conditions. For patients with severe comorbidities PDC should be recommended, reserving HP and STC for patients with colonic ischaemia or perforation complicating malignant obstruction.

Update: Role of surgery in acute necrotizing pancreatitis.

Acute necrotizing pancreatitis is a prevalent disease with high morbidity and mortality. The development of radiologic and endoscopic techniques to manage pancreatic necrosis commands a multidisciplinary approach, which has considerably decreased the need for laparotomy. The objective of this update is to define the role of surgery in the multidisciplinary approach to management of necrotizing acute pancreatitis.

Diffuse malignant peritoneal mesothelioma: Evaluation of systemic chemotherapy with comprehensive treatment through the RENAPE Database: Multi-Institutional Retrospective Study.

PURPOSE: Diffuse malignant peritoneal mesothelioma (DMPM) is a severe disease with mainly locoregional evolution. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is the reported treatment with the longest survival. The aim of this study was to evaluate the impact of perioperative systemic chemotherapy strategies on survival and postoperative outcomes in patients with DMPM treated with curative intent with CRS-HIPEC, using a multi-institutional database: the French RENAPE network. PATIENTS AND METHODS: From 1991 to 2014, 126 DMPM patients underwent CRS-HIPEC at 20 tertiary centres. The population was divided into four groups according to perioperative treatment: only neoadjuvant chemotherapy (NA), only adjuvant chemotherapy (ADJ), perioperative chemotherapy (PO) and no chemotherapy before or after CRS-HIPEC (NoC). RESULTS: All groups (NA: n = 42; ADJ: n = 16; PO: n = 16; NoC: n = 48) were comparable regarding clinicopathological data and main DMPM prognostic factors. After a median follow-up of 61 months, the 5-year overall survival (OS) was 40%, 67%, 62% and 56% in NA, ADJ, PO and NoC groups, respectively (P = 0.049). Major complications occurred for 41%, 45%, 35% and 41% of patients from NA, ADJ, PO and NoC groups, respectively (P = 0.299). In multivariate analysis, NA was independently associated with worse OS (hazard ratio, 2.30; 95% confidence interval, 1.07-4.94; P = 0.033). CONCLUSION: This retrospective study suggests that adjuvant chemotherapy may delay recurrence and improve survival and that NA may impact negatively the survival for patients with DMPM who underwent CRS-HIPEC with curative intent. Upfront CRS and HIPEC should be considered when achievable, waiting for stronger level of scientific evidence.

No impact on long-term survival of prolonged ICU stay and re-admission for patients undergoing cytoreductive surgery with HIPEC.

BACKGROUND: Cytoreductive surgery (CRS) and Hyperthermic intraperitoneal chemotherapy (HIPEC) are promising new approaches of peritoneal metastases. However these surgical procedures are associated with a high morbidity rate thus intensive care (IC) management following serious complications may be warranted for these patients. The impact of the prolonged IC stay or re-admission on long-term survival remains unknown. METHODS: We retrospectively analysed 122 consecutive HIPEC procedures over a one year period (2010-2011) in a single academic hospital. We analysed complications that would lead to prolonged stay or re-admission into ICU and analysed long term follow-up in patients whether they required intensive care (ICU group) or not (Control group). RESULTS: ICU group represented 26.2% of the cohort mainly due to septic or haemorrhagic shock. Among them acute kidney injury and respiratory failure were present in 50% and 47% respectively. Cohort overall mortality rate was of 5.7%. Patients were followed for 4 years and survival analysis was performed adjusting for main confounding factors in a Cox survival model. Survival was not different between groups, with a median survival of 38 months [32; 44] vs. 33 months [26; 39] in the ICU group and Control group respectively. CONCLUSION: Prolonged stay or re-admission into ICU does not seem to statistically impact long term prognosis of patients undergoing CRS with HIPEC.