Peritoneal mesothelioma: PSOGI/EURACAN clinical practice guidelines for diagnosis, treatment and follow-up

Clinical features and prognostic analysis of 14 cases of appendiceal mixed neuroendocrine-non-neuroendocrine tumors with peritoneal pseudomyxoma

BACKGROUND

Appendiceal mixed neuroendocrine-non-neuroendocrine neoplasms (a-MiNENs) combined with peritoneal pseudomyxoma (PMP) represent an exceptionally rare and clinically challenging entity. This study aims to elucidate the clinical characteristics of this unique tumor subtype and identify critical prognostic factors, thereby providing insights into the management and outcomes of affected patients.

METHODS

We conducted a retrospective analysis of 14 patients diagnosed with a-MiNEN and PMP at the Department of Myxoma, Aerospace Center Hospital, between January 2014 and September 2022. Data included demographics, symptoms, tumor grading, treatments, and outcomes.

RESULTS

Pathological evaluation revealed a diverse spectrum of tumor grades and PMP subtypes: 5 cases were classified as G1 neuroendocrine tumors (NET), 4 as G2 NET, and 5 as G3 neuroendocrine carcinoma (NEC). Regarding PMP subtypes, 5 cases had disseminated peritoneal adenomucinosis (DPAM), 4 had peritoneal mucinous carcinomatosis (PMCA), and 5 had peritoneal mucinous carcinomatosis with signet ring cell carcinoma (PMCA-S). The median postoperative survival time was 28.55 months, with 1-year and 2-year survival rates of 80.0% and 66.7%, respectively. Patients aged < 60 years, male sex, absence of right hemicolectomy, postoperative peritoneal cancer index (PCI) ≥ 25, and perineural invasion demonstrated significantly lower 1-year and 2-year survival rates compared to their counterparts, with distinct separation observed in the Kaplan-Meier curves. These factors likely reflect biological differences in disease progression, inadequate surgical debulking, and aggressive tumor behavior.

CONCLUSIONS

a-MiNEN with PMP progresses rapidly. Young patients, male patients, those with absence of right hemicolectomy, postoperative PCI ≥ 25 and perineural invasion may face poorer outcomes. This study, one of the few to analyze this rare condition, underscores the need for targeted treatments and further validation in larger cohorts.

National Guidelines for Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in Peritoneal Malignancies: A Worldwide Systematic Review and Recommendations of Strength Analysis

BACKGROUND

National guidelines (GLs) for surgical cytoreduction (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in the management of peritoneal malignancies (PMs) vary across countries, scientific societies, and government agencies. This study aimed to systematically review and compare the recommendations for CRS/HIPEC in the treatment of ovarian cancer (EOC), gastric cancer, colorectal cancer (CRC), mesothelioma, and pseudomyxoma peritonei (PMP).

METHODS

Medical databases, search engines, and national websites of 193 countries were queried using artificial intelligence (AI)-powered software for scientific societies and/or government agencies guidelines. The study excluded consensus statements and guidelines without appropriate references. Non-English guidelines were translated, and data, including GRADE strength of recommendations, were extracted.

RESULTS

The study analyzed 138 guidelines, 24 for gastric cancer, 36 for colorectal cancer, 29 for primary ovarian cancer (p-)EOC, 28 for recurrent ovarian cancer (r-)EOC, 10 for mesothelioma, and 11 for PMP. Guidelines were retrieved from 51 (26.4%) nations, mostly from developed countries (62.1%; p < 0.001). The CRS procedure received robust positive recommendations (GRADE I/IIa) for CRC (74.2%), p-/r-EOC (100%/78.5%), PMP (90.9%), and mesothelioma (90.0%). Conversely, CRS was not indicated for gastric cancer (61.6%, GRADE III; p < 0.001). The HIPEC procedure had robust positive recommendations for PMP (90.9%) and mesothelioma (90.0%), but was controversial for p-EOC (42.3%) and CRC (38.0%) and contraindicated for r-EOC (80.0%) and gastric cancer (62.4%) (p < 0.001).

CONCLUSION

National guidelines concordantly recommend CRS for colorectal cancer, ovarian cancer, PMP, and mesothelioma. In contrast, HIPEC recommendations are less homogeneously shared, except for PMP and mesothelioma. No positive concordance exists among guidelines on gastric cancer for CRS nor HIPEC. Furthermore, high-level evidence is needed to strengthen future guidelines on peritoneal metastases.

Clinical Significance of Tumor-Infiltrating Lymphocytes in Malignant Peritoneal Mesothelioma: A Single-Center Study of 143 Cases

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is a rare malignant tumor with high mortality rate and extremely poor prognosis. The tumor immune microenvironment, particularly tumor-infiltrating lymphocytes (TILs), plays a critical role in disease progression and treatment response. This study aimed to analyze the correlation between the level of TILs and the main clinicopathological characteristics and prognosis of MPM.

PATIENTS AND METHODS

A total of 143 postoperative specimens from patients with MPM following cytoreductive surgery were collected. Postoperative specimens were stained with hematoxylin and eosin (H&E). The level of TILs was quantitatively analyzed by QuPath 0.3.2 software. Univariate and multivariate analyses were conducted to investigate the correlation between TILs level and other conventional clinicopathological characteristics.

RESULTS

Among the 143 patients with MPM, 73 were male (51.0%) and 70 were female (49.0%), with a median age of 55 (range 24-73) years. There were 72 (50.3%) cases with low TILs, and 71 (49.7%) cases with high TILs. Univariate analysis showed that TIL level (low versus high) was negatively correlated with the following seven clinicopathological factors: surgery history, Ki-67 index, preoperative CA125 level, peritoneal cancer index (PCI) index, bleeding volume, red blood cell (RBC) transfusion volume, and ascites volume (all P < 0.05). Multivariate analysis indicated that TIL level was independently negatively correlated with preoperative carbohydrate antigen (CA)125 level (odds ratio 0.394, 95% CI 0.179-0.866, P = 0.020). Cox regression analysis suggested that high TILs was independently associated with better prognosis of MPM. Moreover, a cohort of patients who received preoperative chemotherapy combined with targeted therapy were evaluated for response. Kaplan-Meier curve showed that high infiltration of TILs predicted better overall survival in patients undergoing treatment.

CONCLUSIONS

TILs could be a useful indicator for predicting prognosis and guiding personalized treatment strategies in patients with MPM.

Multicystic peritoneal mesothelioma in the myometrium during pregnancy: A case report and literature review

Multicystic peritoneal mesothelioma (MCPM) is a rare tumor originating from mesothelial cells, primarily affecting women of reproductive age and typically found in the pelvic peritoneum. Its occurrence in the myometrium is extremely rare. Currently, there have been no reported cases of MCPM in the myometrium during pregnancy, and existing clinical guidelines do not provide specific management recommendations for this condition. This article aimed to explore the diagnosis, management, and treatment for MCPM in the myometrium during pregnancy, thereby providing a valuable reference for clinicians dealing with similar cases.

Abdominal and concomitant thoracic HIPEC, named HITAC : Technique and post-operative courses

INTRODUCTION

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is the preferred treatment for selected patients with carcinomatosis. When diaphragmatic involvement occurs, partial diaphragm resection (DR) is necessary to achieve complete cytoreduction (CC-0). In cases of macroscopic pleural invasion detected during CRS, abdominal and intrathoracic HIPEC (HITAC) through the diaphragm may be considered if pleural and peritoneal CC0 can be obtained.

OBJECTIVES

To report the combined procedure technique, postoperative course, morbidity, and long-term outcomes.

METHODS

A monocentric database was used to identify cases.

RESULTS

Seven synchronous HITAC cases were identified. Median PCI was 12 (3-39). Inflow catheter placement was behind the spleen, with outflow in the right thorax. Four patients had anastomosis and two splenectomy. Oxaliplatin was used in 4 HITAC, mitomycin in 1, and cisplatin in 2. Surgery lasted a median of 580mins (300-720), with extubation 2-4h post-op, or on day 1. Median thoracic drainage on day 1 was 657mL (300-1600), decreasing by day 3. Median drain removal was on day 8 (7-17), with hospital stay of 12 days (8-16). One patient had a postoperative pancreatic fistula and pneumonia, while the remaining 6 had no major complications. One-month residual pleural effusion was noted in one case. No pleural recurrence was observed for PMP, with a median follow-up of 88 months (30-166).

CONCLUSIONS

Combined HIPEC and intrathoracic chemotherapy is feasible without major risks. Thoracic drainage can produce high volumes postoperatively. Favorable long-term outcomes are observed in low-grade PMP.

SS, Bhandoria G, Chatterjee A, Deo SVS, Garach N, Guru A, Kumar N, Kumar R, Rajagopal AK, Kumar S, Mehta S, Mishra D, Pawar A, Prabhu A, Sinukumar S, Solanki S, Sharma V, Sheshadri RA, Bhatt A. The INDEPSO-ISPSM Consensus on Peritoneal Malignancies-Methodology

The numerous international guidelines on cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) do not cover many clinically relevant issues for which evidence is limited and some regional issues (HIPEC in limited resource settings, age-limit for CRS, etc.). We describe the methodology of a consensus CRS and HIPEC for peritoneal malignancies carried out under the aegis of the two national societies for peritoneal oncology-INDEPSO and ISPSM. The modified Delphi technique was used with two rounds of voting. Eight key topics were selected by a working group of 29 members. Questionnaires comprising of closed-ended questions were disseminated through the online SurveyMonkey (http://www.surveymonkey.com) platform. A panel of 56 surgical, gastrointestinal, and gynecologic oncologists with a minimum of 5 years of experience with CRS-HIPEC voted on 260 questions. A consensus was reached if any of the options received 70% or more votes (> 90% = strong consensus). The response rate was 98.2% in round I and 94.6% in round II. A consensus was achieved on 80.7% questions after two rounds (43.0% after round I; 36.9% after round II). It was the highest in the enhanced recovery after surgery (ERAS) section (93.3%) and the lowest (68.0%) for ovarian cancer. A strong consensus was reached on 59 (22.6%) questions (highest for  the technical section (34.2%); lowest in the ERAS section (16.6%)). This consensus which had a high rate of participation should be a useful clinical resource for surgeons treating peritoneal malignancies in India and other regions with a similar demographic and socioeconomic background.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13193-024-02118-2.

Multisocietal Consensus on the Use of Cytoreductive Surgery and HIPEC for the Treatment of Diffuse Malignant Peritoneal Mesothelioma: A GRADE Approach for Evidence Evaluation and Recommendation

The Peritoneal Surface Oncology Group International (PSOGI) previously issued a recommendation endorsing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for treating diffuse malignant peritoneal mesothelioma (DMPM). However, broader acceptance of this approach, particularly within some segments of medical oncology, remains limited. To address this, PSOGI initiated a multisociety consensus effort, involving multidisciplinary International Societies, to strengthen and expand the endorsement of CRS-HIPEC for DMPM. Using the GRADE ADOLOPMENT approach, the expert panel systematically reviewed existing guidelines and evaluated the available evidence to reinforce the recommendation. The panel unanimously recommended CRS-HIPEC for a carefully selected subset of DMPM patients, emphasizing that this approach offers the best potential for improved survival compared to systemic chemotherapy alone. Despite the very low certainty of evidence, a strong recommendation was issued, reflecting the panel's recognition of the life-threatening feature of DMPM and the limited efficacy of systemic chemotherapy. This consensus also highlights the importance of centralized and expert-driven care. The recommendation aligns with previous guidelines and underscores the critical need for broader acceptance of this treatment strategy in managing this rare and aggressive malignancy.

Surgical and oncological outcome after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal mesothelioma : A retrospective single center experience

BACKGROUND

Peritoneal mesothelioma (PM) is a rare disease with various histopathological subtypes. For malignant peritoneal mesothelioma and borderline subgroups locoregional therapy with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has been implemented. The aim of our study was to retrospectively present the outcome after CRS and HIPEC for patients with different subtypes of peritoneal mesothelioma.

METHODS

In total 15 patients received CRS and HIPEC due to peritoneal mesothelioma at our tertiary referral hospital between 2013 and 2022. Surgical and oncologic outcomes of 14 of those patients were retrospectively evaluated as one patient was lost to follow-up.

RESULTS

The cohort consisted of 9 patients with diffuse malignant peritoneal mesothelioma (64.3%), 3 patients with multicystic peritoneal mesothelioma (21.4%) and 2 patients with well-differentiated peritoneal mesothelioma (14.3%). Complete cytoreduction was possible in 85.7% (n = 12). The major complication rate was 28.6% (n = 4) and the reoperation rate was 14.3% (n = 2). Median follow-up was 55 months (standard error, SE 15.0%, 95% confidence interval, CI 25.6-84.4 months). Over this time period 64.3% (n = 9) had no evidence of disease, 21.4% (n = 3) were alive with disease and 14.3% (n = 2) died of peritoneal mesothelioma. The median recurrence-free survival of patients was 13 months (SE 13.0%, 95% CI 0.0-32.2 months). None of the patients with multicystic peritoneal mesothelioma had evidence of disease at the time of last follow-up.

CONCLUSION

Patients with peritoneal mesothelioma should receive locoregional treatment as good oncological results can be achieved with reasonable postoperative morbidity. Thus, awareness is necessary for this rare but potentially aggressive disease to offer the best medical care.

Comprehensive genomic and transcriptomic analysis enables molecularly guided therapy options in peritoneal and pleural mesothelioma

INTRODUCTION

Peritoneal, pericardial and pleural mesothelioma (PeM/PcM/PM) are rare and aggressive diseases with limited survival. Molecularly guided therapy is currently not part of standard care.

METHODS

This study integrates molecular and clinical data from 51 patients (among them 28 PM, one PcM, 21 PeM and one synchronous PeM/PM) enrolled in the National Center for Tumor Diseases and the German Cancer Consortium (NCT/DKTK) Molecularly Aided Stratification for Tumor Eradication Research (MASTER), a multicenter precision oncology registry trial addressing adults with rare advanced-stage cancers. Analysis comprised both somatic and germline whole exome sequencing/whole genome sequencing and transcriptome analysis leading to personalized treatment recommendations issued by a dedicated molecular tumor board. To assess clinical efficacy, progression-free survival (PFS) ratios comparing molecularly informed therapies (PFS2) to preceding systemic therapies (PFS1) were calculated. Efficacy of immune checkpoint inhibition applied during the observation period was assessed accordingly.

RESULTS

Cancer-related genes altered in more than 5 out of 44 assessable patients were BAP1, CDKN2A, NF2, SETD2 and TP53. Somatic (n = 23) or germline (n = 9) alterations in homologous recombination-related genes were detected in 27/44 patients. In 21/44 cases, they were supported by positive combined homologous recombination deficiency scores or BRCAness signature. Following American College of Medical Genetics and Genomics guidelines, (likely) pathogenic germline variants in autosomal dominant cancer predisposition genes were found in 8/51 patients. Molecular tumor board recommendations were issued in 46 cases and applied in 6 cases. Mean PFS ratio was 2.45 (n = 5). Median PFS2 was 6.5 months (n = 6), median PFS1 was 4.0 months (n = 5). A total of 27 patients received immune checkpoint inhibition during the observation period leading to a mean PFS ratio of 1.69 (n = 19).

CONCLUSIONS

In mesothelioma, comprehensive molecular analysis can provide valuable clinically actionable information. Molecularly informed therapy recommendations can lead to clinical benefit.

Reforming Cancer Multidisciplinary Team Meetings: Introducing a Novel Clinical Radiological Assessment Meeting (CRAM) to Reduce Response Times and Workloads

Introduction Multidisciplinary team (MDT) meetings are now considered part of the standard of care for decision-making and management of patients with cancer. However, most MDTs now face capacity issues and supplementary approaches should be considered. We report our experience with a novel clinical radiological assessment meeting (CRAM) as a 'mini-MDT' to expedite decision-making and enhance the function of the parallel specialist MDT.  Methods A retrospective analysis of new referrals to a high-volume peritoneal malignancy unit between September 2016 and August 2018 was performed. Time to first response and decision following referral were assessed for the traditional referral pathway and after the introduction of the CRAM in September 2017. Response times were calculated from the receipt of the referral to the date of the first response and were classified into one of four categories: 'specialist peritoneal malignancy MDT review,' 'outpatient review,' 'recommendation for local follow-up', or 'further information required'. The Mann-Whitney U test was used to compare the response times between the two pathways. Results In total, 1478 new referrals were received in the two-year period, 769 pre-CRAM and 709 after CRAM introduction. The median referral to first response time was eight days using traditional pathways and five days after the introduction of the CRAM (p <0.001). In the traditional pathway, 234/769 (30.4%) patients were discussed further in the specialist MDT, compared with 122/709 (17.2%) after the CRAM assessment.  Conclusion A novel CRAM significantly reduced first response times to the referring team facilitating rapid and safe assessment with quicker decisions for the patients. It enabled more appropriate use of an ever-expanding MDT.

Analysis of TERT mRNA Levels and Clinicopathological Features in Patients with Peritoneal Mesothelioma

BACKGROUND/OBJECTIVES

Telomerase reverse transcriptase (TERT) is the catalytic subunit of the telomerase enzyme responsible for telomere length maintenance and is an important cancer hallmark. Our study aimed to clarify the mRNA expression of TERT in peritoneal mesothelioma (PeM), and to explore the relationship between its expression and the clinicopathological parameters and prognosis of patients with PeM.

METHODS

In a cohort of 13 MpeM patients, we evaluated histotype, nuclear grade, mitotic count, necrosis, inflammation, Ki67, BAP1, MTAP and p16 expression by immunohistochemistry, p16/CDKN2A status by FISH and TERT mRNA expression by RNAscope.

RESULTS

Our results showed several statistical correlations between TERT mRNA-score and other investigated features: (i) a poor positive correlation with BAP1 score (r = 0.06340; p ≤ 0.0001); (ii) a moderate positive correlation with p16 FISH del homo (r = 0.6340; p ≤ 0.0001); (iii) a fair negative correlation with p16 FISH del hetero (r = -0.3965; p ≤ 0.0001); a negative poor correlation with MTAP (r = -0.2443; p ≤ 0.0001); and (iv) a negative fair correlation with inflammatory infiltrate (r = -0.5407; p = 0.0233). Moreover, patients survive for a significantly longer time if they have a low mitotic index adjusted (2-4 mitotic figures per 2 mm2) (p ≤ 0.0001), are male (p = 0.0152), lose BAP1 (p = 0.0152), are p16 positive and present no deletion or heterozygous for p16 (p ≤ 0.01).

CONCLUSIONS

TERT is highly expressed in PeM, but it is not one of the crucial factors in evaluating the prognosis of patients. Nevertheless, the results validate the prognostic significance of the mitotic index, BAP1 loss and p16/CDKN2A status.

Biomarkers to predict the benefits of immune‑checkpoint blockade‑based therapy in patients with malignant peritoneal mesothelioma (Review)

Malignant peritoneal mesothelioma (MPeM) is a type of rare and highly lethal tumor. Immune checkpoint blockade (ICB)-based therapy has shown encouraging clinical activity for MPeM. However, no definitive biomarkers have been identified for predicting which patients with MPeM will benefit from ICB-based therapy. At present, there are several novel potential biomarkers proposed for predicting the response to ICB-based therapy, and biomarkers available in MPeM cells and in the tumor microenvironment have been identified with the potential to predict the efficacy of ICB-based therapy in MPeM. According to the molecular characteristics of MPeM itself, the feasibility of biomarkers in practice, and the body of available evidence, we hypothesize that the following five types of biomarkers can be used to predict the response of ICB-based therapy in patients with MPeM: Tertiary lymphoid structures, immune checkpoints and their ligands, fusion gene neoantigen burden, BRCA1-associated protein-1 haploinsufficiency and transcriptome-based biomarkers. The present review discusses the value and limitations of each type of biomarker, and potential solutions to address the limitations are proposed. The aim of the present review is to provide a background for future studies on ICB-based therapy for MPeM.

A case of ovarian mesothelioma with VHL mutation diagnosed by immunohistochemistry and literature review

The malignant mesothelioma mainly develops in the pleura and peritoneum, while primary ovarian mesothelioma is very rare. Here, we report the first case of primary ovarian mesothelioma (clear cell variant) with VHL mutations in the world based on the results of histomorphology, immunohistochemistry, and genetic testing. This is an extremely rare type of tumor that has not been reported so far. Through the literature search, we reviewed primary ovarian mesothelioma, focusing on its differential diagnosis and molecular genetics. The purpose of this paper is to deepen the flexible selection and application of immunohistochemical markers in mesothelioma, so as to reduce missed diagnosis and misdiagnosis.

Review of 2022 PSOGI/RENAPE Consensus on HIPEC

The 2022 PSOGI (Peritoneal Surface Oncology Group International) and RENAPE (French Network for Rare Peritoneal Malignancies) consensus on hyperthermic intraperitoneal chemotherapy (HIPEC) was a comprehensive effort aimed at standardizing treatment protocols for various peritoneal malignancies. This initiative is critical due to the wide range of technical variations in HIPEC procedures and the resulting need for standardization to ensure consistent and effective patient care and meaningful audit of multicenter data.

Drug sensitivity tumor cell clusters in malignant peritoneal mesothelioma

BACKGROUND

To explore the most effective adjuvant chemotherapy regimen for malignant peritoneal mesothelioma (MPM) through patient derived tumor-like cell clusters (PTC) drug sensitivity test.

METHODS

PTC were cultured in vitro with intraoperative specimens, and drug sensitivity test was performed to calculate the most effective chemotherapy regimen for MPM. The patients were divided into conventional and individualized chemotherapy group according to whether they received PTC drug testing. Univariate and multivariate analyses were conducted to identify independent prognostic factors.

RESULTS

Among 186 MPM patients included, 63 underwent PTC culture and drug sensitivity test. The results showed that the most effective chemotherapy regimen was oxaliplatin + gemcitabine. After propensity score matching, a total of 64 patients were enrolled in the following study, including 32 patients receiving individualized chemotherapy guided by PTC drug results as group 1 and 32 patients receiving conventional chemotherapy as group 2. Survival analysis showed that the median OS of group 1 was not reached, significantly longer than that of group 2 (23.5 months) (p < 0.05).

CONCLUSIONS

Compared with conventional chemotherapy, individualized chemotherapy guided by PTC drug sensitivity tests can prolong patient survival, and oxaliplatin + gemcitabine + apatinib could be the optimal adjuvant treatment regimen for MPM.

PIPAC Pharmacologic and Clinical Data

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) emerged as an innovative intraperitoneal chemotherapy delivery system to overcome the issue of limited efficacy of systemic therapies to induce response in peritoneal malignancies. Promising results for patients with mesothelioma peritonei and peritoneal metastasis from gastric, ovarian, colorectal, pancreatic, and hepatobiliary tumors origin are changing the landscape for patients otherwise just facing palliative treatment. Ongoing trials will shed more light on the actual benefits of PIPAC.

Multi-Society Guideline on Cytoreductive Surgery and HIPEC: Methodology and Overview of the Results

To provide evidence-based guidelines about Peritoneal Surface Malignancy (PSM) treatment for the Peritoneal Surfaces Oncology Group International. The GRADE ADOLOPMENT method was used to adapt recommendations from the Italian Medical Oncology Association Guideline on PSM. Seven scientific society were involved to form five guideline panels composed of 28 medical professionals from 14 countries. Panelists prioritized 7 relevant questions. A knowledge synthesis team updated evidence and summarized information. The panel agreed on seven recommendations.

Is extereme cytoreductive surgery beneficial to survival ın malignant peritoneal mesothelioma?

INTRODUCTION

Malign peritoneal mesothelioma (MPM) is an uncommon disease that is difficult to treat. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) are the gold standards for treating MPM. Sometimes extreme cytoreductive surgery (eCRS) is required to achieve complete cytoreduction, which is one of the most important prognostic factors. There is limited information in the literature about the contribution of eCRS in patients with MPM. In this study, we aimed to investigate the impact of eCRS on survival and perioperative outcomes.

METHODS

The Department of Surgical Oncology at Cumhuriyet University database was retrospectively reviewed for MPM patients who underwent CRS-HIPEC between January 2004 and December 2018. Patients who underwent CRS-HIPEC were divided into eCRS and less extensive CRS (leCRS) groups. A resection of ≥5 organs or ≥3 small bowel anastomoses were defined as eCRS. Both groups were compared regarding survival, demographic information, and perioperative outcomes.

RESULTS

A total of 31 patients were included. eCRS-HIPEC was used in 15 patients. Complete cytoreduction (CC score 0/1) was achieved in all 31 patients. Compared to leCRS, the eCRS group had a longer median length of stay, longer intensive care unit stay, a higher median peritoneal cancer index (PCI), higher intraoperative blood loss, more frequent occurrence of any complication, and a longer operative time (all p values < 0.001). Clavien Dindo 3-4 complications, ASA, and gender were similar in both groups of patients (p > 0.05). It was found that there was no significant difference between the OS of the eCRS and leCRS groups (37.5 vs. 42.8 months, p = 0.895).

CONCLUSIONS

Rates of serious complications and morbidity are similar in patients undergoing eCRS compared to leCRS. In patients with high PCI and multiorgan involvement, complete cytoreduction can be achieved by performing eCRS, and survival results equivalent to those with low PCI can be achieved.

Intraoperative urinary tract resection and construction in CRS + HIPEC procedures: a single center retrospective analysis

INTRODUCTION

The safety and efficacy of CRS + HIPEC combined with urinary tract resection and reconstruction are controversial. This study aims to summarize the clinicopathological features and to evaluate the safety and survival prognosis of CRS + HIPEC combined with urinary tract resection and reconstruction.

METHODS

The patients who underwent urinary tract resection and reconstruction as part of CRS surgery were retrospectively selected from our disease-specific database for analysis. The clinicopathological characteristics, treatment-related variables, perioperative adverse events (AEs), and survival outcomes were studied using a descriptive approach and the K-M analysis with log-rank comparison.

RESULTS

Forty-nine patients were enrolled. Perioperative serious AEs (SAEs) were observed in 11 patients (22.4%), with urinary SAEs occurring in 3 patients (6.1%). Additionally, there were 23 cases (46.8%) involving urinary adverse events (UAEs). The median overall survival (OS) in the entire cohort was 59.2 (95%CI: 42.1-76.4) months. The median OS of the UAE group and No-UAE group were 59.2 months (95%CI not reached), and 50.5 (95%CI: 11.5 to 89.6) months, respectively, with no significant difference (P = 0.475). Furthermore, there were no significant differences in OS based on the grade of UAEs or the number of UAEs (P = 0.562 and P = 0.622, respectively).

CONCLUSION

The combination of CRS + HIPEC with urinary tract resection and reconstruction is associated with a high incidence of Grade I-II UAEs, which do not have an impact on OS. The safety profile of this combined technique is acceptable. However, this is a retrospective single-center single-arm analysis, with limitations of generalizability and potential selection bias. The findings need high-level validation.

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.

Impact of Perioperative Systemic Chemotherapy on Survival for Patients Who have Diffuse Malignant Peritoneal Mesothelioma Treated with CRS-HIPEC

BACKGROUND

The available data on the role of perioperative systemic chemotherapy (SC) for diffuse malignant peritoneal mesothelioma (DMPM) patients undergoing (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is heterogeneous and unstandardized. This study aimed to evaluate the impact of SC on the survival outcomes of DMPM patients undergoing CRS-HIPEC and to identify prognostic factors that affect the decision to administer SC.

METHODS

Patients who underwent CRS-HIPEC in the National Cancer Institute Milan (1995-2020) were retrospectively analyzed using propensity score-matching of known covariates. The patients were grouped into three groups: group A (neoadjuvant chemotherapy [NACT] and no-SC), group B (no-SC and adjuvant chemotherapy [ACT]), and group C (NACT and ACT). Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meir method, and prognostic factors were calculated using the Cox-regression method.

RESULTS

After a median follow-up period of 45 months (95% confidence interval [CI], 6.348-83.652 months) for group A, 115 months (95% CI, 44.379-185.621 months) for group B, and 88 months (95% CI, 3.296-172.704 months) for group C, the study analyzed 154 DMPM patients consisting of matched group A (NACT: 60 + no-SC: 52 = 112), group B (ACT: 38 + no-SC: 38 = 76), and group C (NACT: 31 + ACT: 31 = 62). The patients undergoing ACT had better 5-year OS and PFS than the patients undergoing NACT. In the multivariate analysis, ACT was significantly associated with improved OS by 48% (hazard ratio [HR], 0.52; 95% CI, 0.280-0.965, p = 0.038). For PFS, the association of ACT did not reach statistical significance (HR, 0.531; 95% CI, 0.266-1.058; p = 0.072).

CONCLUSION

The optimum treatment sequence for DMPM is CRS-HIPEC followed by adjuvant chemotherapy for high-risk patients. Upfront surgery appears preferable to NACT for patients amenable to complete CRS.

Oral Anlotinib Maintenance Therapy for an Advanced Malignant Peritoneal Mesothelioma Diagnosed by Laparoscopy After Initial Misdiagnosis to Obtain Longer Progression-Free Survival: Case Report and Literature Review

Malignant peritoneal mesothelioma (MPeM) is a rare and highly invasive malignant tumor with a lack of specificity in clinical manifestations, which can easily lead to misdiagnosis and missed diagnosis. Due to the difficulty of early diagnosis, most patients are already in the advanced stage when diagnosed, and the prognosis is poor. At present, there is no standard treatment strategy, and the existing treatment methods are not effective, the duration of remission is short, which cannot meet the clinical needs. Here we describe a patient with advanced MPeM, initially misdiagnosed as ovarian cancer, who responded to treatment with bevacizumab in combination with albumin-bound paclitaxel and cisplatin. In preparation for cytoreductive surgery (CRS), MPeM was confirmed by laparoscopic peritoneal nodule biopsy combined with histological and immunohistochemical results. Subsequently, due to intolerable neurotoxicity after chemotherapy, she received oral anlotinib therapy on April 25, 2022, and remained stable disease (SD) with the medication, having achieved more than 14 months of progression-free survival (PFS) as of the date of our manuscript submission. The patient's total treatment time was over 19 months. These treatments delayed tumor progression, reduced drug side effects, maintained a good quality of life, and further extended overall survival (OS). Our experience is that on the one hand, it is necessary to increase the clinician's understanding of the disease, and make full use of tissue samples and immunohistochemical staining to reduce the occurrence of misdiagnosis. On the other hand, based on preliminary evidence, we found that oral anlotinib offers a viable maintenance treatment strategy for patients with advanced mesothelioma, which needs to be further explored in future studies.

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.

Malignant Peritoneal Mesothelioma: An In-Depth and Up-to-Date Review of Pathogenesis, Diagnosis, Management and Future Directions

Malignant peritoneal mesothelioma (MPM) is an extremely rare malignancy usually confined to the abdominal cavity. With an aggressive natural history, morbidity and mortality are consequences of progressive locoregional effects within the peritoneal cavity. The first reported case was in the early 20th century, however, due to the rare nature of the disease and a large gap in understanding of the clinicopathological effects, the next reported MPM cases were only published half a decade later. Since then, there has been exponential growth in our understanding of the disease, however, there are no prospective data and a paucity of literature regarding management. Traditionally, patients were treated with systemic therapy and the outcomes were very poor, with a median survival of less than one year. However, with the advent of cytoreductive surgery and locoregional chemotherapy, there have been significant improvements in survival. Even more recently, with an improved understanding of the molecular pathogenesis of MPM, there have been reports of improved outcomes with novel therapies. Given the disastrous natural history of MPM, the limited data, and the lack of universal treatment guidelines, an in-depth review of the past, present, and future of MPM is critical to improve treatment regimens and, subsequently, patient outcomes.

Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) for peritoneal mesothelioma: Canadian practices and outcomes

INTRODUCTION

Peritoneal mesothelioma (PM) is a rare malignancy originating from the peritoneal lining. Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) is the standard-of-care for patients with isolated PM. Due to a paucity of prospective data there are several different HIPEC protocols. The aims of this study are to describe the CRS and HIPEC protocols for PM and patient outcomes across Canada.

METHODS

A multicenter retrospective study was performed on patients diagnosed and treated for PM with CRS and HIPEC in four major peritoneal disease centers in Canada between 2000 and 2021. Data on patient characteristics, treatment patterns, postoperative morbidity, recurrence, and survival were collected.

RESULTS

A total of 72 patients were identified. Mean age was 52 years (17-75) and 37.5% were male. Epithelioid (70.1%) and multicystic (13%) mesothelioma were the most common subtypes. Twenty-one patients (30%) were treated with neoadjuvant chemotherapy. CRS and HIPEC was performed in 64 patients (91.4%). Of these, the mean PCI was 22 (2-39) and cisplatin+doxorubicin was the most common HIPEC regimen (n = 33, 51.6%). A semi-closed coliseum technique was used in 68.8% of HIPECs and the mean duration of surgery was 486 min (90-1052). Clavien-Dindo III or IV complications occurred in 12 patients (16.9%). With a median follow-up of 24 months (0.2-104.4), we found a 5-year overall survival of 61% and a 5-year recurrence-free survival of 35%.

CONCLUSION

CRS and HIPEC is a safe and effective treatment modality for well-selected patients with PM, with some achieving prolonged survival.

Metachronous double primary malignant tumors with nasopharyngeal carcinoma and diffuse malignant peritoneal mesothelioma accompanied with paraneoplastic syndromes treated with nivolumab: A case report

RATIONALE

Multiple primary malignant tumors are rare and challenging to diagnose. Diffuse malignant peritoneal mesothelioma (DMPM) originate from the peritoneum, which lacks specific clinical manifestations and is difficult to diagnose, with a short survival about 10 to 13 months for inoperable ones. This is the first report of metachronous double primary malignant tumors in nasopharyngeal carcinoma and DMPM accompanied with paraneoplastic syndromes.

PATIENT CONCERNS

A 61-year-old man presented with abdominal discomfort with a history of nasopharyngeal carcinoma 5 years ago.

DIAGNOSES

The diagnosis of DMPM was finally confirmed by laparoscopic mesenteric biopsies. Paraneoplastic syndromes including increased platelets were present when diagnosis, followed by increased neutrophils after disease progression.

INTERVENTIONS

Due to intolerable for surgery, he was treated with pemetrexed combined with nivolumab, intraperitoneal infusion of nivolumab, radiotherapy, anlotinib and maintenance treatment of nivolumab.

OUTCOMES

Progression-free survival in first line is 12 months, overall survival is 23 months.

LESSONS

This indicate that comprehensive treatment including immunotherapy may be helpful for inoperable DMPM patients with nasopharyngeal carcinoma accompanied with paraneoplastic syndromes.

The SAlzburg PEritoneal SUrface CAlculator (SAPESUCA): The First Web-Based Application for Peritoneal Surface Area Quantification

(1) Background: Peritoneal metastasized colorectal cancer is associated with a worse prognosis. The combination of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) showed promising results in selected patients, but standardization is lacking so far. We present the first tool enabling standardized peritoneal surface area (PSA) quantification in patients undergoing CRS and HIPEC: The SAlzburg PEritoneal SUrface CAlculator (SAPESUCA). (2) Methods: SAPESUCA was programmed using the R-Shiny framework. The application was validated in 23 consecutive colon cancer patients who received 27 closed oxaliplatin-based HIPECs between 2016 and 2020. The programming algorithm incorporates the patient's body surface area and its correlated peritoneal surface area (PSA) based on the 13 Peritoneal Cancer Index (PCI) regions. (3) Results: Patients' median age was 56 years. Median PCI was 9. SAPESUCA revealed a mean PSA of 18,613 cm² ± 1951 of all patients before compared to 13,681 cm² ± 2866 after CRS. The Central PCI region revealed the highest mean peritonectomy extent (1517 cm² ± 737). The peritonectomy extent correlated significantly with PCI score and postoperative morbidity. The simulated mean oxaliplatin dose differed significantly before and after CRS (558 mg/m² ± 58.4 vs. 409 mg/m² ± 86.1; p < 0.0001). (4) Conclusion: SAPESUCA is the first free web-based app for standardized determination of the resected and remaining PSA after CRS. The tool enables chemotherapeutic dose adjustment to the remaining PSA.

Extrapelvic Endometriosis Mimicking Peritoneal Surface Malignancy: Case Report and a Review of Literature

Extrapelvic endometriosis is a rare presentation of endometriosis with atypical clinical symptoms. It can mimic peritoneal surface malignancy, as well as some abdominal infectious diseases. A 29-year-old Moroccan woman presented with abdominal pain, progressive abdominal distention, and an intermittent inflammatory syndrome. Imaging revealed multiple, progressively growing abdominal cysts. She had elevated tumor markers CA125 and CA19.9. Despite thorough investigation, several differential diagnoses persisted for a long time. Definitive pathological diagnosis could only be established after debulking surgery. Literature review on malignant and benign conditions causing multicystic abdominal distention is provided. When definitive diagnosis is not established, but suspicion for peritoneal malignancy remains, a debulking procedure can be undertaken. Organ preservation can be pursued whenever benign disease is still considered. In case of malignancy, short-term (curative) debulking procedure with or without hyperthermic intraperitoneal chemotherapy (HIPEC) can be proposed.

Peritoneal Mesothelioma: Systematic Review of Hyperthermic Intraperitoneal Chemotherapy (HIPEC) Protocol Outcomes

Diffuse malignant peritoneal mesothelioma (DMPM) prognosis was improved by the locoregional treatment combining cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). HIPEC is a multiparametric treatment with multiple protocols proposed and reviewed in this work. A systematic review of medical literature was performed according to PRISMA guidelines. The search strategy used "malignant peritoneal mesothelioma" and "HIPEC" as keywords in three databases. Studies were included if reporting precisely the HIPEC regimen and the related outcomes, if comparing regimen, or if reporting national/international guidelines. The GRADE methodology was used to rate the level of evidence. Twenty-eight studies were included in this review: 1 was a meta-analysis, 18 reported cohort outcomes, 4 retrospectively compared HIPEC regimens, and 5 were guidelines. Six HIPEC regimens were found, 4 with one drug (cisplatin, mitomycine-C, carboplatin, oxaliplatin), 2 using two drugs (cisplatin-doxorubicin or cisplatin-mitomycine-C). Cisplatin, up to 250 mg/m2 over 90 min, appeared as the key HIPEC drug with a toxicity profile well controlled by the concomitant intravenous perfusion of sodium thiosulfate. Comparative studies tended to show that a bi-drug regimen led to better long-term oncologic outcomes, with cisplatin 50 mg/m2 plus doxorubicin 15 mg/m2 being safe and more efficient. This late protocol was the most widely used and recommended in 3 out of 4 international guidelines. Cisplatin was the preferred drug for HIPEC in DMPM patients. Most of the time, it was combined with doxorubicin for 90 min. A harmonization of protocols and further comparative studies are needed to optimize HIPEC regimen choice.

Treatment of Peritoneal Surface Malignancies by Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in Spain: Results of the National Registry of the Spanish Group of Peritoneal Oncologic Surgery (REGECOP)

INTRODUCTION

Treatment of Peritoneal Surface Malignancies (PSM) with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has achieved results never seen before in these patients, which classically have a poor prognosis. The possibility of conducting clinical trials in these diseases is complicated, since some of them are rare, so the analysis of large databases provides very valuable scientific information. The aim of this study is to analyze the global results of the National Registry of the Spanish Group of Peritoneal Oncologic Surgery (REGECOP), whose objective is to register all patients scheduled for HIPEC nationwide.

METHODS

This is a retrospective analysis of the data recorded in the REGECOP from 36 Spanish hospitals from 2001 to 2021. There were 4159 surgical interventions in 3980 patients.

RESULTS

66% are women and 34% are men with a median age of 59 years (range 17-86). 41.5% of the patients were treated for Peritoneal Metastases (PM) of colorectal cancer (CRC); 32.4% were women with ovarian cancer (OC) with PM; 12.8% were treated for pseudomyxoma peritonei (PMP); 6.2% had PM from gastric cancer (GC); 4.9% had PM of non-conventional origin; and, finally, 2.1% of cases were patients diagnosed with peritoneal mesothelioma. The median Peritoneal Cancer Index (PCI) was 9 (0-39), and complete cytoreduction was achieved in 81.7% of the procedures. Severe morbidity (Dindo-Clavien grade III-IV) was observed in 17.7% of surgeries, with 2.1% mortality. Median hospital stay was 11 days (0-259). Median overall survival (OS) was 41 months for CRC patients, 55 months for women with OC, was not reached in PMP patients, was 14 months for GC patients, and 66 months in mesothelioma patients.

CONCLUSIONS

large databases provide extremely useful data. CRS with HIPEC in referral centers is a safe treatment with encouraging oncologic results in PSM.

Pleurectomy and decortication are associated with better survival for bicavitary cytoreductive surgery for mesothelioma compared with extrapleural pneumonectomy

OBJECTIVES

Mesothelioma is a nearly uniformly fatal tumor. Multimodality therapy including cytoreductive surgery and chemotherapy is associated with long-term survival in some patients. Cytoreductive surgery for thoracic disease includes a lung-sparing operation called an "extended pleurectomy/decortication" or a lung-sacrificing surgery called an "extrapleural pneumonectomy." The benefit of cytoreductive surgery for bicavitary disease (chest and abdomen) is poorly understood. Our objective was to evaluate the long-term survivals for patients undergoing cytoreductive surgery for bicavitary disease and to determine whether any prognostic factors were associated with outcome.

METHODS

We reviewed our Institutional Review Board-approved, institutional, International Association for the Study of Lung Cancer Mesothelioma Staging Project database. Inclusion criteria were all patients who underwent cytoreductive surgery for bicavitary disease. Overall survival was calculated by Kaplan-Meier methodology. All International Association for the Study of Lung Cancer database elements were evaluated by univariable analysis.

RESULTS

From February 2014 to August 2021, 440 patients with mesothelioma were evaluated. Fourteen patients (3%) underwent cytoreductive surgery of both chest and abdomen as a planned 2-stage operation. Most patients (13/14; 93%) underwent chest surgery before abdomen surgery. For the entire cohort, the median overall survival was 33.6 months with a 5-year survival of 20%. Extended pleurectomy/decortication was associated with a better outcome compared with extrapleural pneumonectomy, with median overall survivals of 58.2 versus 13.5 months, respectively.

CONCLUSIONS

For a highly selected group of patients with bicavitary mesothelioma, long-term survival can be achieved with an aggressive, staged surgical approach. The patients who undergo extended pleurectomy/decortication with preservation of the lung appear to have more favorable outcomes compared with patients undergoing extrapleural pneumonectomy.

Peritoneal Mesothelioma in a High Volume Peritoneal Surface Malignancies Unit

Diffuse malignant peritoneal mesothelioma (PM) is a rare neoplasm, traditionally associated with a poor prognosis. There are other varieties of PM that are even less frequent and of uncertain malignancy. Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has achieved prolonged survival in selected patients. The aim of this study is to analyze the patients with PM assessed in our center. Clinicopathological characteristics, diagnostic procedures and survival results from patients with PM appraised at our unit, according to the applied treatment, were analyzed. Seventeen patients were assessed between 2007 and 2019. Three cases had multicystic PM that were treated with complete CRS + HIPEC; all patients are alive and free of disease after a long follow-up. Three other cases had biphasic PM; a curative treatment could be performed in none of them, and their survival was minimal (<6 moths). Lastly, 11 cases with epithelioid PM were treated. Two cases were considered unresectable at laparoscopy (PCI 39); one of them had a long survival (67 months) with three iterative laparoscopic palliatives HIPECs for refractory ascites. The other nine cases were treated with curative CRS + HIPEC, with a median PCI of 14 (range 4–25), and a median overall survival (OS) of 58 months, with a 5-year OS of 47.4%. In conclusion, CRS + HIPEC, when possible, appears to be the optimal treatment for patients with PM. Knowledge of this therapeutic option is crucial, both to offer it to patients and to avoid delays in their referral to appropriate centers for treatment.

Radiologic staging of peritoneal and retroperitoneal disease

Peritoneal and retroperitoneal tumors consist of a heterogenous group of benign and malignant lesions of different origin. Due to often complex multidisciplinary treatment concepts in patients with peritoneal surface malignancies radiological imaging plays a pivotal role regarding the therapeutic options. Moreover, tumor entity, abdominal tumor distribution and common as well as rare differential diagnoses have to be taken into account. Using different radiological modalities non-invasive pretherapeutic diagnostics might be significantly improved. KEY POINTS::   · Diagnostic CT is a valuable part of the initial diagnostic approach to peritoneal surface malignancies.. · Sensitivity might be increased by the additional use of dwMRI and PET/CT considering tumor entity and individual diagnostic issues.. · The Peritoneal Cancer Index (PCI) should be determined independent of radiologic modality.. CITATION FORMAT: · Glockzin G, Helmberger T. Radiologic staging of peritoneal and retroperitoneal disease. Fortschr Röntgenstr 2023; DOI: 10.1055/a-1999-7057.

Ultrasound-guided day-case wide-bore percutaneous mucin aspiration in advanced pseudomyxoma peritonei

AIM

To evaluate percutaneous ultrasound-guided day-case mucin aspiration in advanced pseudomyxoma peritonei (PMP) using a wide-bore drain with regards to its safety and efficacy.

MATERIALS AND METHODS

All patients who underwent percutaneous mucin aspiration for PMP between 2019-2021 at a single national peritoneal tumour service were included in this study. Under local anaesthesia, a suction-enabled 28-32 F catheter was used for drainage following wire-guided track dilatation. The volume drained and difference in abdominal girth pre- and post-procedure were measured. Patients graded difficulty in breathing and abdominal discomfort pre- and post-procedure. Histology reports were reviewed.

RESULTS

Sixteen patients received 56 percutaneous mucin aspirations between 2019-2021. The aetiology was a low-grade appendiceal mucinous neoplasm (LAMN) in 50% of patients. The mean amount of mucin drained was 7,320 ± 3,000ml (range 300-13,500 ml). The mean reduction in abdominal girth post-procedure was 12.2 ± 5 cm (range 0-27 cm). Only grade 1 complications were observed.

CONCLUSION

Percutaneous ultrasound-guided day-case aspiration of mucin for advanced and recurrent PMP using a wide-bore drain is a safe and effective procedure. It may be used in the palliative setting or as a bridge to surgery in the very symptomatic patient or if there is a reversible contraindication to surgery.

Diagnostic and Therapeutic Pathway in Diffuse Malignant Peritoneal Mesothelioma

Diffuse malignant peritoneal mesothelioma (DMPM) is a rare form of mesothelioma that carries a very poor prognosis. The 5-year overall survival is about 20% (±5.9). Survival is optimal for patients suitable for cytoreductive surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC), with a median OS ranging from 34 to 92 months. However, selecting patients for surgery remains a complex task and requires a careful preoperative workup, rational analysis of prognostic profiles, and risk prediction models. Systemic chemotherapy could be offered: (1) in the adjuvant setting for high-risk patients; (2) for patients not eligible for CRS; and (3) for those with recurrent disease. It mainly includes the combination of Platin compound with Pemetrexed or immunotherapy. The biology of DMPM is still largely unknown. However, progress has been made on some fronts, such as telomere maintenance mechanisms, deregulation of apoptosis, tyrosine kinase pathways, and mutation of BRCA1-associated protein 1 (BAP1). Future perspectives should include translational research to improve our understanding of the disease biology to identify druggable targets. We should also clear the role of immune checkpoint inhibitors and investigate new locoregional technologies, such as pressurized intraperitoneal aerosol chemotherapy (PIPAC) or normothermic intraperitoneal chemotherapy (NIPEC).

Diffuse malignant peritoneal mesothelioma: A review

Diffuse malignant peritoneal mesothelioma (DMPM) is an unusual and life-threatening locally invasive tumor. The morbidity and mortality of the disease are associated with progressive local effects in the abdominal cavity, such as abdominal distention, painful sensations, and early saturation with reduced oral intake, which eventually lead to intestinal obstruction and cachexia. Computed tomography (CT) has been widely used as a first-line diagnostic tool for DMPM. In addition, the most sensitive immunohistochemical markers of DMPM include WT 1, D2-40, and calmodulin. This paradigm has altered with the advancements in the immunohistochemical analysis of BRCA1-Associated Protein 1 (BAP1) the lack of BAP1 expression shows the diagnosis of malignancy. DMPM is resistant to conventional chemotherapies. Therefore, the gold standard for the treatment of DMPM is the combination of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The overexpression of the phosphatidylinositol 3-kinase (PI3K)/AKT serine/threonine kinase 1 (AKT)/mammalian target of rapamycin (mTOR) signaling pathway drives the malignant phenotype of DMPM, thereby showing promising potential for the treatment of DMPM. The coordinated activities among multiple RTKs are directly involved in the biological processes of DMPM, suggesting that the combined inhibition of the PI3K and mTOR signaling pathways might be an effective measure. This treatment strategy can be easily implemented in clinical practice. However, the combined inhibition of ERBB1(HER1)/ERBB2 (HER2) and ERBB3 (HER3) requires further investigations. Thus, based on these, the discovery of novel targeted therapies might be crucial to improving the prognosis of DMPM patients.

Malignant peritoneal mesothelioma with massive ascites as the first symptom: A case report

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is an extremely rare tumor with nonspecific clinical manifestations, which is extremely difficult to diagnose. Herein, we reported a case of MPM in the abdominal cavity with massive short-term ascites as the first symptom.

CASE SUMMARY

A 65-year-old woman presented to the hospital with abdominal pain, distention, and shortness of breath that persisted for 15 d. The serum CA-125 level was 1075 U/mL. The abdominal computed tomography showed massive ascites and no obvious tumor lesions. The pathological examination of the ascitic fluid showed numerous heterotypic cells with some papillary structures. The immunohistochemistry and fluorescence in situ hybridization showed the deletion of CDX2 (-), WT-1 (-), Ki-67 (about 10% +), CEA (-), Glut-1 (+++), desmin (-), PD-L1 (-), and CDKN2A (P16). The final diagnosis was MPM. The patient refused tumor cytoreductive surgery and received two cycles of cisplatin plus pemetrexed bidirectional chemotherapy. In the second cycle, she received an additional cycle of hyperthermic intraperitoneal chemotherapy and immune checkpoint inhibitor therapy due to massive recalcitrant ascites. She died of disease progression 2 mo after diagnosis.

CONCLUSION

In case of massive unexplained ascites, the possibility of MPM should not be excluded to avoid misdiagnosis and delay in treatment.

Advances in the management of peritoneal malignancies

Peritoneal surface malignancies (PSMs) are usually associated with a poor prognosis. Nonetheless, in line with advances in the management of most abdominopelvic metastatic diseases, considerable progress has been made over the past decade. An improved understanding of disease biology has led to the more accurate prediction of neoplasia aggressiveness and the treatment response and has been reflected in the proposal of new classification systems. Achieving complete cytoreductive surgery remains the cornerstone of curative-intent treatment of PSMs. Alongside centralization in expert centres, enabling the delivery of multimodal and multidisciplinary strategies, preoperative management is a crucial step in order to select patients who are most likely to benefit from surgery. Depending on the specific PSM, the role of intraperitoneal chemotherapy and of perioperative systemic chemotherapy, in particular, in the neoadjuvant setting, is established in certain scenarios but questioned in several others, although more prospective data are required. In this Review, we describe advances in all aspects of the management of PSMs including disease biology, assessment and improvement of disease resectability, perioperative management, systemic therapy and pre-emptive management, and we speculate on future research directions.

Comprehensive Treatment Algorithms of the Swiss Peritoneal Cancer Group for Peritoneal Cancer of Gastrointestinal Origin

Peritoneal cancer (PC) is a dire finding, yet in selected patients, long-term survival is possible. Complete cytoreductive surgery (CRS) together with combination immunochemotherapy is essential to achieve cure. Hyperthermic intraperitoneal chemotherapy (HIPEC) and pressurized intraperitoneal aerosol chemotherapy (PIPAC) are increasingly added to the multimodal treatment. The Swiss Peritoneal Cancer Group (SPCG) is an interdisciplinary group of expert clinicians. It has developed comprehensive treatment algorithms for patients with PC from pseudomyxoma peritonei, peritoneal mesothelioma, gastric, and colorectal origin. They include multimodal neoadjuvant treatment, surgical resection, and palliative care. The indication for and results of CRS HIPEC and PIPAC are discussed in light of the current literature. Institutional volume and clinical expertise required to achieve best outcomes are underlined, while inclusion of patients considered for CRS HIPEC and PIPAC in a clinical registry is strongly advised. The present recommendations are in line with current international guidelines and provide the first comprehensive treatment proposal for patients with PC including intraperitoneal chemotherapy. The SPCG comprehensive treatment algorithms provide evidence-based guidance for the multimodal care of patients with PC of gastrointestinal origin that were endorsed by all Swiss clinicians routinely involved in the multimodal care of these challenging patients.

Prognostic factors of malignant peritoneal mesothelioma: a retrospective study of 52 female patients

BACKGROUND

Prognosis in malignant peritoneal mesothelioma (MPM) remains poor, and the associated factors are unclear. Therefore, this study aimed to investigate the prognostic factors of MPM.

METHODS

A total of 52 female MPM patients treated in 2012-2017 were retrospectively analyzed. Kaplan-Meier survival curves were generated for survival analysis by the log-rank test. The Cox regression model was used for univariate and multivariate analyses.

RESULTS

Univariate analysis showed that median survival time (MST) was longer in the epithelioid type compared with the sarcomatoid type (12 months vs 5 months); cumulative survival rates at 12 months were 45.7% and 0%, respectively (P=0.005). MST was longer in patients with proliferating cell nuclear antigen (Ki67) ≤ 10% compared with those with Ki67 > 10% (15 months vs 11 months). Cumulative survival rates at 12 months were 60.0% and 28.1%, respectively (P=0.036). MSTs in patients administered peritoneal biopsy or adnexectomy + paclitaxel + platinum perfusion, peritoneal biopsy (or adnexectomy) + pemetrexed + platinum perfusion, cytoreductive surgery + paclitaxel + platinum perfusion, and cytoreductive surgery + pemetrexed + platinum perfusion were 6, 11, 12, and 24 months, respectively, with cumulative survival rates at 12 months of 0%, 35.7%, 45.5%, and 73.3%, respectively. Survival time after cytoreductive surgery combined with pemetrexed + platinum was the longest. In multivariate analysis, pathological type, T staging, and therapeutic regimen were independent prognostic factors of MPM (P < 0.05).

CONCLUSIONS

Prognosis in MPM is associated with pathological subtype, clinical staging, cytoreductive surgery, and subsequent pemetrexed use. Radical cytoreductive surgery and postoperative use of pemetrexed prolong survival.

The Road to Technical Proficiency in Cytoreductive Surgery for Peritoneal Carcinomatosis: Risk-Adjusted Cumulative Summation Analysis

Background

Cytoreductive surgery (CRS) is a technically demanding procedure, and there is considerable debate about its safe application. This study investigated the learning curve for CRS and the clinical outcomes of consecutive patients treated by a single surgeon at a single institution.

Methods

We collected 251 consecutive patients who underwent CRS for peritoneal metastases by a single surgeon at Fondazione Policlinico Universitario A. Gemelli IRCCS, between January 2016 and December 2020. The learning curve was estimated using the cumulative summation analysis (CUSUM) for operative time (OT). Risk-adjusted CUSUM (RA-CUSUM) charts were developed using a composite variable (surgical failure), defined as the occurrence of at least one of the following events: major postoperative complications (Clavien–Dindo grade ≥3), blood loss ≥500 mL, incomplete cytoreduction. Three learning phases were thus derived from the RA-CUSUM analysis, and were compared in terms of perioperative outcomes.

Results

CUSUM-OT showed that the operation time improved significantly after the 161^th case. RA-CUSUM analysis allowed to break the CRS learning curve into three different phases: phase 1, “the learning phase” (cases 1–99), phase 2 “the experienced phase” (cases 100–188), and phase 3, “the mastership phase” (cases 189–251). The rate of major postoperative complications decreased significantly over the three phases (p = 0.019). Operative time decreased significantly as well (p = 0.031) and was significantly shorter in phase 3 with respect to the other two phases (phase 3 vs phase 2: 420 min vs 500 min, p = 0.017; phase 3 vs phase 1: 420 min vs 503 min, p = 0.021). Blood loss consistently decreased throughout the three phases (p = 0.001). The rate of incomplete cytoreduction was significantly lower in phase 3 than in phase 2 (4.8% vs 14.6%, p = 0.043).

Conclusion

The CRS failure rate stabilized after the first 99 cases, and the complete surgical proficiency was achieved after 189 cases. A standardised and mentored learning model is a safer strategy to shorten the learning process, to reduce morbidity and mortality, to improve oncologic outcomes.

Selected Patients With Peritoneal Metastases From Breast Cancer May Benefit From Cytoreductive Surgery: The Results of a Multicenter Survey

BACKGROUND

Even though breast cancer is the most frequent extra-abdominal tumor causing peritoneal metastases, clear clinical guidelines are lacking. Our aim is to establish whether cytoreductive surgery (CRS) could be considered in selected patients with peritoneal metastases from breast cancer (PMBC) to manage abdominal spread and allow patients to resume or complete other medical treatments.

METHODS

We considered patients with PMBC treated in 10 referral centers from January 2002 to May 2019. Clinical data included primary cancer characteristics (age, histology, and TNM) and data on metastatic disease (interval between primary BC and PM, molecular subtype, other metastases, and peritoneal spread). Overall survival (OS) was estimated using the Kaplan-Meier method. Univariate and multivariable data for OS were analyzed using the Cox proportional hazards model.

RESULTS

Of the 49 women with PMBC, 20 were treated with curative aim (CRS with or without HIPEC) and 29 were treated with non-curative procedures. The 10-year OS rate was 27%. Patients treated with curative intent had a better OS than patients treated with non-curative procedures (89.2% vs. 6% at 36 months, p < 0.001). Risk factors significantly influencing survival were age at primary BC, interval between BC and PM diagnosis, extra-peritoneal metastases, and molecular subtype.

CONCLUSIONS

The improved outcome in selected cases after a multidisciplinary approach including surgery should lead researchers to regard PMBC patients with greater attention despite their scarce epidemiological impact. Our collective efforts give new information, suggest room for improvement, and point to further research for a hitherto poorly studied aspect of metastatic BC.

The role of imaging in diagnosis and management of malignant peritoneal mesothelioma: a systematic review

PURPOSE

Imaging of the peritoneum and related pathology is a challenge. Among peritoneal diseases, malignant peritoneal mesothelioma (MPeM) is an uncommon tumor with poor prognosis. To date, there are no specific guidelines or imaging protocols dedicated for the peritoneum and MPeM. The objective of this study was to analyze the literature describing imaging modalities used for MPeM to determine their relative clinical efficacy and review commonly reported imaging features of MPeM to promote standardized reporting.

METHODS

We performed a systematic review of original research articles discussing imaging modalities in MPeM from 1999 to 2020. Effectiveness measures and common findings were compared across imaging modalities.

RESULTS

Among 582 studies analyzed, the most-used imaging modality was CT (54.3%). In the differentiation of MPeM from peritoneal carcinomatosis, one study found CT had a diagnostic sensitivity of 53%, specificity of 100%, and accuracy of 68%. Two studies found fluorodeoxyglucose positron emission tomography (FDG-PET) had sensitivity of 86-92%, specificity of 83-89%, and accuracy of 87-89%. Another study found magnetic resonance imaging (MRI) was the best predictor of the peritoneal carcinomatosis index. Characteristics shown to best differentiate MPeM from other diseases included ascites, peritoneal thickening, mesenteric thickening, pleural plaques, maximum tumor dimension, and number of masses.

CONCLUSION

Most published MPeM imaging studies utilized CT. PET/CT or MRI appear promising, and future studies should compare effectiveness of these modalities. MPeM imaging reports should highlight ascites, number of and maximum tumor dimension, peritoneal/mesenteric thickening, and associated pleural plaques, allowing for better aggregation of MPeM imaging data across studies.

Challenging Diagnostic Process for a Malignant Peritoneal Mesothelioma Patient With Ascites and Pleural Effusion: A Case Report and Review of the Literature

Malignant peritoneal mesothelioma (MPM) is a sporadic and fatal disease of the peritoneal lining. Its diagnosis has been known to be challenging, time-consuming, and money-consuming. In this paper, we report an MPM case of a 58-year-old man with severe abdominal distension. After he had received all kinds of auxiliary examination, including computed tomography scans of the chest and whole abdomen, examinations of peripheral and pleural fluid, positron emission tomography, and twice fine-needle peritoneal biopsies, his disease still could not be confirmed. Eventually, the patient was diagnosed with MPM through laparoscopic biopsy and IHC. From this case, we concluded that clinicians can gradually discover and diagnose the disease through 1) high platelet and CA125 levels and CT imaging results, 2) cytologic examinations of ascites and pleural fluid, 3) peritoneal biopsies (fine-needle biopsy, laparoscopy biopsy), and 4) histopathological examinations and immunohistochemistry findings. The diagnostic process involving this patient can be an example to demonstrate the effectiveness of various auxiliary examination methods in MPM diagnosis.

HIPEC in Peritoneal Metastasis of Gastric Origin: A Systematic Review of Regimens and Techniques

(1) Background: Peritoneal metastasis in gastric cancer is associated with a poor prognosis. Complete cytoreductive surgery including gastrectomy and complete removal of all peritoneal lesions followed by hyperthermic intraperitoneal chemotherapy (HIPEC) achieves promising results. There exists an immersive variety of approaches for HIPEC that makes it difficult to weigh different results obtained in the literature. In order to enable standardization and development of HIPEC, we here present a systematic review of different drug regimens and technical approaches. (2) Methods: PubMed, Embase, and the Cochrane Library were systematically searched on 26 May 2021 using the mesh terms “intraperitoneal chemotherapy AND gastric cancer”. Under consideration of systematic review guidelines, articles reporting on HIPEC in combination with CRS were selected. Data on duration, drugs, dosage, and other application parameters as well as morbidity and long term survival data were extracted for subsequent statistical analysis, tabulation, and descriptive synthesis. We assessed the risk of bias due to inhomogeneity of the patient cohort and incompleteness of report of HIPEC parameters. (3) Results: Out of 1421 screened publications, 42 publications presenting data from 1325 patients met the criteria. Most of the publications were single institutional retrospective cohort studies. The most common HIPEC regimen is performed after gastrointestinal anastomosis and consists of 50–200 mg/m² cisplatinum and 30–40 mg/m² mytomycin C at 42–43 °C for 60–90 min in a closed abdomen HIPEC system with three tubes. Almost every study reported incompletely on HIPEC parameters. Lower rates of anastomotic leakage were reported in studies that performed HIPEC after gastrointestinal anastomosis. Studies that performed open HIPEC and integrated a two-drug regimen indicated better overall survival rates. (4) Discussion: This is an exhaustive overview of the use of drug regimens and techniques for HIPEC after CRS for gastric cancer peritoneal metastasis. Other indications and application modes of intraperitoneal chemotherapy such as prophylactic or palliative HIPEC apart from CRS were not addressed. (5) Conclusion: Complete report of HIPEC parameters should be included in every publication. A consensus for dose expression either per BSA or as flat dose is desirable for comparison of the drug regimens. Despite numerous variations, we identified the most common regimens and techniques and their advantages and disadvantages according to the data in the literature. More phase I/II studies are needed to identify the best approach for HIPEC. (6) Other: This review was not supported by third parties.

Molecular Pathways in Peritoneal Mesothelioma: A Minireview of New Insights

Mesothelioma is a rare malignant neoplasm with poor survival. It mainly affects the pleura (90%) but can arise in all serous cavities: peritoneum (5-10%), pericardium and tunica vaginalis testis (<1%). The onset of pleural mesothelioma is strictly related to asbestos exposure with a long latency time. The causal link with asbestos has also been suggested for peritoneal mesothelioma, while the importance of exposure in the onset of pericardial and tunica vaginalis testis mesotheliomas is not well known. Mesothelioma remains an aggressive and fatal disease with a five-year mortality rate higher than 95%. However, new therapeutic approaches based on molecular-targeted and immunomodulatory therapies are being explored but have conflicting results. In this context, the identification of critical targets appears mandatory. Awareness of the molecular and physiological changes leading to the neoplastic degeneration of mesothelial cells and the identification of gene mutations, epigenetic alterations, gene expression profiles and altered pathways could be helpful for selecting targetable mechanisms and molecules. In this review, we aimed to report recent research in the last 20 years focusing on the molecular pathways and prognostic factors in peritoneal mesothelioma and their possible diagnostic and therapeutic implications.