Pemetrexed plus gemcitabine as first-line chemotherapy for patients with peritoneal mesothelioma: final report of a phase II trial

Systemic Therapy and Surgical Management of Peritoneal Mesothelioma

Malignant peritoneal mesothelioma is an aggressive and rare disease that affects the serosal membranes. The outcomes of patients who suffer from this disease have improved because of the advances in imaging, genetics, and treatment strategies such as systemic therapy and cytoreduction surgery and hyperthermic intraperitoneal chemotherapy. Multidisciplinary care remains essential for enhancing survival and quality of life.

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.

Organoids derived from patients provide a new opportunity for research and individualized treatment of malignant peritoneal mesothelioma

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is an extremely rare and highly invasive tumor. Due to the lack of accurate models that reflect the biological characteristics of primary tumors, studying MPM remains challenging and is associated with an exceedingly unfavorable prognosis. This study was aimed to establish a new potential preclinical model for MPM using patient-derived MPM organoids (MPMOs) and to comprehensively evaluate the practicality of this model in medical research and its feasibility in guiding individualized patient treatment.

METHODS

MPMOs were constructed using tumor tissue from MPM patients. Histopathological analysis and whole genome sequencing (WGS) were employed to determine the ability of MPMOs to replicate the original tumor's genetic and histological characteristics. The subcutaneous and orthotopic xenograft models were employed to assess the feasibility of establishing an in vivo model of MPM. MPMOs were also used to conduct drug screening and compare the results with retrospective analysis of patients after treatment, in order to evaluate the potential of MPMOs in predicting the effectiveness of drugs in MPM patients.

RESULTS

We successfully established a culture method for human MPM organoids using tumor tissue from MPM patients and provided a comprehensive description of the necessary medium components for MPMOs. Pathological examination and WGS revealed that MPMOs accurately represented the histological characteristics and genomic heterogeneity of the original tumors. In terms of application, the success rate of creating subcutaneous and orthotopic xenograft models using MPMOs was 88% and 100% respectively. Drug sensitivity assays demonstrated that MPMOs have different medication responses, and these differences were compatible with the real situation of the patients.

CONCLUSION

This study presents a method for generating human MPM organoids, which can serve as a valuable research tool and contribute to the advancement of MPM research. Additionally, these organoids can be utilized as a means to evaluate the effectiveness of drug treatments for MPM patients, offering a model for personalized treatment approaches.

Molecular alterations and potential actionable mutations in peritoneal mesothelioma: a scoping review of high-throughput sequencing studies

BACKGROUND

Peritoneal mesothelioma (PeM) is a rare malignancy with a poor prognosis. Currently there is a lack of effective systemic therapies. Due to the rarity of PeM, it is challenging to study new treatment options. Off-label use of targeted drugs could be an effective approach. This scoping review aims to explore the genomic landscape of PeM to identify potential therapeutic targets.

MATERIALS AND METHODS

A systematic literature search of Embase, Medline, Web of Science, the Cochrane Library, and Google Scholar was carried out up to 1 November 2022. Studies that reported on molecular alterations in PeM detected by high-throughput sequencing techniques were included. Genes that were altered in ≥1% of PeMs were selected for the identification of potential targeted therapies.

RESULTS

Thirteen articles were included, comprising 824 PeM patients. In total, 142 genes were altered in ≥1% of patients, of which 7 genes were altered in ≥10%. BAP1 was the most commonly altered gene (50%). Other commonly altered genes were NF2 (25%), CDKN2A (23%), CDKN2B (17%), PBRM1 (15%), TP53 (14%), and SETD2 (13%). In total, 17% of PeM patients were carriers of a germline mutation, mainly in BAP1 (7%).

CONCLUSIONS

This scoping review provides an overview of the mutational landscape of PeM. Germline mutations might be a larger contributor to the incidence of PeM than previously thought. Currently available targeted therapy options are limited, but several targeted agents [such as poly (ADP-ribose) polymerase (PARP), enhancer of zeste homolog 2 (EZH2), and cyclin-dependent kinase 4/6 (CDK4/6) inhibitors] were identified that might provide new targeted therapy options in the future.

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.

High-Risk Peritoneal Mesothelioma: Does Metronomic Chemotherapy Have a Role?

Objective

To evaluate the feasibility, tolerance, and efficacy of OMCT (oral metronomic chemotherapy) after CRS + HIPEC for peritoneal mesothelioma in patients with poor prognostic factors: PCI > 20, incomplete CRS, poor performance status, or progression on systemic chemotherapy.

Methods

A retrospective analysis of patients undergoing CRS + HIPEC for peritoneal mesothelioma and receiving OMCT for poor risk factors.

Results

Sixteen patients underwent CRS + HIPEC between 2013 and 2017. The median PCI was 31.5. Complete cytoreduction (CC-0/1) was obtained in 8 patients (50%). All 16 received HIPEC except one patient with baseline renal dysfunction.Thirteen patients had PCI > 20 where only 5 had CC-0/1. Of 8 suboptimal cytoreduction (CC-2/3), 7 received OMCT (6 for progression on chemotherapy and one for mixed histology). Three patients had PCI < 20 and all had CC-0/1 clearance. Only one received OMCT for progression on adjuvant chemotherapy. Patients receiving OMCT for progression on adjuvant chemotherapy (ACT) were in poor PS.The median follow-up was 13.4 months. Five are alive with the disease (three are on OMCT). Six are alive without disease (2 are on OMCT). The mean OS was 24.3 months and the mean DFS was 18 months. Outcomes were similar between CC-0/1 and CC-2/3 groups, OMCT vs no OMCT groups.All patients receiving OMCT for progression on neoadjuvant chemotherapy had better survival (alive at 12, 20, 32, 36 months) compared to those receiving OMCT for progression on the ACT (p = 0.012).

Conclusion

OMCT is a good alternative in high-volume peritoneal mesothelioma with incomplete cytoreduction and progression on chemotherapy. OMCT may improve outcomes in these scenarios when started early.

Impact of centralization of care for malignant peritoneal mesothelioma: A historical cohort study from the Dutch mesothelioma expert centers

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is a rare and aggressive cancer that has a poor prognosis. An earlier population-based study found that the majority of Dutch patients do not receive anti-cancer treatment. In 2015, Dutch Malignant Mesothelioma care was centralized in two expert centers. We reviewed treatment patterns at these centers, to assess the impact of centralization of MPM care in the Netherlands.

METHODS

Data from all patients referred to the Dutch MPM expert centers from 2014 to 2020, were retrospectively collected. Descriptive statistics regarding referrals, patient and tumor characteristics, and treatment patterns were provided. Population-based incidence rates were provided by the Netherlands Cancer Registry.

RESULTS

From 2014 to 2020, 78 patients were referred to the Dutch Mesothelioma expert centers, of whom 32 were female (41%). From 2014 to 2017, 27 patients were referred, whereas 51 patients were referred from 2018 to 2020. This represents about 24% and 61% of the estimated population incidence, respectively. Treatment patterns were comparable between both periods. Between 2014 and 2018, 33% of patients underwent surgery, 44% systemic therapy, and 22% received best supportive care (BSC), while this was 29%, 37%, and 33% respectively from 2018 to 2020.

CONCLUSION

Centralization of care for patients with MPM resulted in an increase of annual referrals to the Dutch mesothelioma expert centers. While population-based incidence did not change during the study period, the absolute number of patients receiving treatment at our centers did increase. This might be considered a first important step towards better treatment for patients with this fatal disease.

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.

Intraperitoneal paclitaxel for patients with primary malignant peritoneal mesothelioma: a phase I/II dose escalation and safety study-INTERACT MESO

INTRODUCTION

Malignant peritoneal mesothelioma (MPM) is a rare, aggressive tumour arising primarily from the peritoneum. The only potentially curative treatment is cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). However, the majority of patients are not eligible to undergo this treatment. The benefit of systemic treatment for these patients is limited at the cost of considerable morbidity. Hence, there is a need for appropriate palliative treatment options for patients with MPM. As MPM rarely disseminates outside the abdominal cavity, these patients might benefit from local treatment. A higher, more effective dose of chemotherapy can directly be delivered at the site of the disease. Systemic uptake will be limited, likely resulting in less toxicity. The aim of the INTERACT MESO trial is to determine the maximum tolerable dose of intraperitoneal paclitaxel monotherapy in patients with MPM. Secondary endpoints are to assess safety and toxicity, feasibility and the pharmacokinetic profile of this treatment.

METHODS AND ANALYSIS

The INTERACT MESO trial is a prospective, open-label, single-centre, phase I study with a classic three-plus-three dose escalation design. The study population consists of adult patients with primary MPM, without extra-abdominal disease, who are not eligible to undergo CRS-HIPEC. According to standard of care work-up for CRS-HIPEC, patients will undergo diagnostic laparoscopy to determine the feasibility of CRS-HIPEC. In case CRS-HIPEC is not considered feasible, a peritoneal port-a-cath (PAC) system will be placed. Through this PAC, 8-16 weekly cycles of intraperitoneal chemotherapy will be administered.

ETHICS AND DISSEMINATION

The Central Committee on Research Involving Human Subjects (CCMO, The Hague, The Netherlands) and the Medical Research Ethics Committee (METC, Rotterdam, The Netherlands) have granted permission to carry out this study protocol. The results of this trial will be submitted for publication in a peer-reviewed scientific journal.

TRIAL REGISTRATION NUMBER

NL9718. EudraCT: 2021-003637-11.

Treatment of Patients with Malignant Peritoneal Mesothelioma

Malignant peritoneal mesothelioma is a rare malignancy arising from the serosa of the peritoneal cavity. It is diagnosed based on suspicious findings on cross sectional imaging and a tissue biopsy showing confirmatory histologic and immunohistochemical features. The disease is hallmarked by its propensity to progress mainly in the peritoneal cavity. In selected patients, surgical cytoreduction and hyperthermic intra-operative peritoneal chemotherapy has become the initial preferred treatment and is associated with provide prolonged in many patients. Systemic chemotherapy using a couplet of cisplatin or gemcitabine with pemetrexed has modest response rates and duration of response. Expression of PD-L1 has been demonstrated in peritoneal mesothelioma tumors and there has been significant interest in the use of check point blockade targeted against PD-L1 in this clinical setting. Future clinical research using a combination of check point blockade with surgical cytoreduction is a high clinical priority.

Primary and metastatic peritoneal surface malignancies

Peritoneal surface malignancies comprise a heterogeneous group of primary tumours, including peritoneal mesothelioma, and peritoneal metastases of other tumours, including ovarian, gastric, colorectal, appendicular or pancreatic cancers. The pathophysiology of peritoneal malignancy is complex and not fully understood. The two main hypotheses are the transformation of mesothelial cells (peritoneal primary tumour) and shedding of cells from a primary tumour with implantation of cells in the peritoneal cavity (peritoneal metastasis). Diagnosis is challenging and often requires modern imaging and interventional techniques, including surgical exploration. In the past decade, new treatments and multimodal strategies helped to improve patient survival and quality of life and the premise that peritoneal malignancies are fatal diseases has been dismissed as management strategies, including complete cytoreductive surgery embedded in perioperative systemic chemotherapy, can provide cure in selected patients. Furthermore, intraperitoneal chemotherapy has become an important part of combination treatments. Improving locoregional treatment delivery to enhance penetration to tumour nodules and reduce systemic uptake is one of the most active research areas. The current main challenges involve not only offering the best treatment option and developing intraperitoneal therapies that are equivalent to current systemic therapies but also defining the optimal treatment sequence according to primary tumour, disease extent and patient preferences. New imaging modalities, less invasive surgery, nanomedicines and targeted therapies are the basis for a new era of intraperitoneal therapy and are beginning to show encouraging outcomes.

Communicating imaging findings in peritoneal mesothelioma: the impact of 'PAUSE' on surgical decision-making

The peritoneal cavity is the second commonest site of mesothelioma after the pleural cavity. There are five histological types of peritoneal mesothelioma with variable symptomatology, clinical presentation and prognosis. Cystic mesothelioma is a borderline malignant neoplasm with a favourable prognosis, well-differentiated papillary mesothelioma is generally a low-grade malignancy, and all other varieties such as epithelioid, sarcomatoid and biphasic mesothelioma are highly malignant types of peritoneal mesothelioma with poor prognosis. Malignant peritoneal mesothelioma was considered inevitably fatal prior to the introduction of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in selected cases where long-term survival and cure could be achieved. However, the survival benefits following CRS and HIPEC mainly depend on completeness of cytoreduction, which come at the cost of high morbidity and potential mortality. Using the acronym 'PAUSE', we aimed at describing the key imaging findings that impact surgical decision-making in patients with peritoneal mesothelioma. PAUSE stands for peritoneal cancer index, ascites and abdominal wall disease, unfavourable sites of involvement, small bowel and mesenteric disease and extraperitoneal disease. Reporting components of 'PAUSE' is crucial for patient selection. Despite limitations of CT in accurately depicting the volume of disease, describing findings in terms of PAUSE plays an important role in excluding patients who might not benefit from CRS and HIPEC.

Prolonged survival with systemic chemotherapy in an advanced malignant mesothelioma: A case report

Peritoneal mesotheliomas are very rare tumors. Their prognosis is poor, average survival does not exceed 1 year after peritoneal cytoreduction. Systemic chemotherapy is considered to have no proven value in the management of peritoneal mesotheliomas. Objective responses with systemic chemotherapy are very rare. We report here a case of an advanced peritoneal mesothelioma which achieved an unexpected partial response with chemotherapy, allowing the patient to have a right colectomy. The patient was referred to a specialized center on HIPEC, but taking in account the long awaiting interval, the HIPEC was judged to be inefficient and then the poursuit of 6 cycles of systemic chemotherapy was decided. The patient is still alive without any symptom and with a good performance status at 59 months after diagnosis. Throughout our case, we provide an encouraging evidence of the role of initial systemic chemotherapy in the downstaging of initially unresectable primary malignant mesothelioma and in the improvement of overall survival.

The Role of Hyperthermic Intraperitoneal Chemotherapy for Non-colorectal Peritoneal Surface Malignancies

BACKGROUND

Peritoneal carcinomatosis, from a variety of gastrointestinal and gynecological malignancies, has been historically challenging to treat and there remains a wide range of biologic aggressiveness in these patients. Malignancies commonly associated with PC include those of colorectal, appendiceal, gastric, ovarian, sarcoma, small intestinal, and primary peritoneal origin among others. Advances in our understanding of this unique disease process have led to significant interest in cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) as an emerging treatment option. The goal of CRS-HIPEC is to remove all visible macroscopic disease while preserving organ function, and then treat microscopic disease through perfusion of the peritoneal cavity with heated chemotherapy.

PURPOSE

Although recent reviews have focused on the management of peritoneal carcinomatosis secondary to colorectal cancer given the publication of several recent randomized controlled trials, the purpose of the current review is to summarize the evidence on CRS-HIPEC for non-colorectal peritoneal surface malignancies, including appendiceal neoplasms, malignant peritoneal mesothelioma, gastric cancer, and ovarian cancer.

RESULTS

While retrospective studies have clarified the importance of prognostic factors such as the peritoneal carcinomatosis index, completeness of cytoreduction, histopathological characteristics, and lymph node positivity, the lack of convincing level 1 evidence for the use of CRS-HIPEC has led to it remaining a highly controversial topic.

CONCLUSION

The decision to utilize CRS-HIPEC should involve a multidisciplinary team approach and evaluation of prognostic factors to balance the short-term morbidity of the operation with maximum long-term benefits. Large, multi-institutional groups and ongoing trials hold promise for clarifying the role of CRS-HIPEC in peritoneal surface malignancies.

Impact of hypoxia on chemoresistance of mesothelioma mediated by the proton-coupled folate transporter, and preclinical activity of new anti-LDH-A compounds

BACKGROUND

Expression of proton-coupled folate transporter (PCFT) is associated with survival of mesothelioma patients treated with pemetrexed, and is reduced by hypoxia, prompting studies to elucidate their correlation.

METHODS

Modulation of glycolytic gene expression was evaluated by PCR arrays in tumour cells and primary cultures growing under hypoxia, in spheroids and after PCFT silencing. Inhibitors of lactate dehydrogenase (LDH-A) were tested in vitro and in vivo. LDH-A expression was determined in tissue microarrays of radically resected malignant pleural mesothelioma (MPM, N = 33) and diffuse peritoneal mesothelioma (DMPM, N = 56) patients.

RESULTS

Overexpression of hypoxia marker CAIX was associated with low PCFT expression and decreased MPM cell growth inhibition by pemetrexed. Through integration of PCR arrays in hypoxic cells and spheroids and following PCFT silencing, we identified the upregulation of LDH-A, which correlated with shorter survival of MPM and DMPM patients. Novel LDH-A inhibitors enhanced spheroid disintegration and displayed synergistic effects with pemetrexed in MPM and gemcitabine in DMPM cells. Studies with bioluminescent hypoxic orthotopic and subcutaneous DMPM athymic-mice models revealed the marked antitumour activity of the LDH-A inhibitor NHI-Glc-2, alone or combined with gemcitabine.

CONCLUSIONS

This study provides novel insights into hypoxia/PCFT-dependent chemoresistance, unravelling the potential prognostic value of LDH-A, and demonstrating the preclinical activity of LDH-A inhibitors.

Peritoneal mesothelioma

Malignant peritoneal mesothelioma (MPM) is a rare and lethal disease of the peritoneal lining, with high variability in biologic aggressiveness. Morbidity and mortality of the disease are related to progressive locoregional effects within the abdominal cavity, such as distention, pain, early satiety, and decreased oral intake that can ultimately lead to bowel obstruction and cachexia. The standard of care for patients with resectable disease remains cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC), with potential survival outcomes greater than 5 years in appropriately selected patients. Patients with inoperable MPM can be offered systemic treatment, although the disease is usually refractory to standard chemotherapic regimens. Patients with MPM should be treated at high volume centers with strong consideration for inclusion in tumor registries and clinical trials. In 2020, research will continue to explore promising genetic and immunologic targets and focus on refinement of surgical methods to optimize CRS-HIPEC approaches.

Peritoneal mesothelioma in Sweden: A population-based study

The study aim was to report survival and morbidity of all patients in Sweden with peritoneal mesothelioma treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) as well as investigate whether the survival has increased on a population level since this treatment was nationalized 2011. Study data were collected from the Swedish HIPEC registry and the Swedish National Cancer Registry. All patients with peritoneal mesothelioma scheduled for CRS/HIPEC treatment in Sweden January 2011 to March 2018 were retrieved from the Swedish HIPEC registry. Clinicopathological and survival data were collected. For population‐level analysis, all patients with diffuse malignant peritoneal mesothelioma (DMPM) were identified from the Swedish National Cancer Registry and data were retrieved from two separate 5‐year time periods: 1999‐2003 and 2011‐2015. Thirty‐two patients were accepted for CRS/HIPEC. Four were open/close cases. Two‐year survival rate was 84% or 59% when excluding borderline peritoneal mesotheliomas (n = 17). Median overall survival was not reached. Grade III‐IV Clavien‐Dindo events occurred in 22% with no mortality. From the national cancer registry, 102 DMPM cases were retrieved: 40 cases between 1999 and 2003, and 62 cases between 2011 and 2015 (corresponding to an increase from 0.9 to 1.24/million/year, P = .04). Six patients (10%) received CRS/HIPEC in the second period. Median OS increased between periods from 7 to 15 months and 5‐year survival from 14% to 29% (P = .03). Peritoneal mesothelioma of both borderline and DMPM subtypes undergoing CRS/HIPEC have good long‐term survival. The incidence of DMPM in Sweden has increased. Overall survival has increased alongside the introduction of CRS/HIPEC, which may be a contributing factor.

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for peritoneal mesothelioma: patient selection and special considerations

Malignant peritoneal mesothelioma (MPM) is a rare, aggressive malignancy that typically presents with vague symptoms, ascites, and/or diffuse peritoneal studding. Despite findings of advanced disease within the peritoneal cavity, spread beyond the abdomen is uncommon. Although advances in systemic chemotherapy have been made, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) remain the mainstay of treatment. Median overall survival of approximately 50 months with CRS/HIPEC has been demonstrated, with age, gender, histologic subtype, peritoneal carcinomatosis index, comorbidities, nodal and extra-abdominal metastases, and completeness of cytoreduction all playing a role in prognosis. In patients with refractory malignant ascites and unresectable disease, complete resolution of ascites and improvement in quality of life have been demonstrated with palliative HIPEC. In appropriately selected patients, CRS/HIPEC plays a critical role in the treatment and palliation of MPM.

Malignant peritoneal mesothelioma: clinical aspects, and therapeutic perspectives

Malignant peritoneal mesothelioma (MPM) is a rare disease with a wide clinical spectrum. It arises from the peritoneal lining and commonly presents with diffuse, extensive spread throughout the abdomen and, more rarely, metastatic spread beyond the abdominal cavity. Computed tomography, magnetic resonance imaging and positron-emission tomography are important diagnostic tools used for the preoperative staging of MPM. The definitive diagnosis is based on histopathological analysis, mainly via immunohistochemistry. In this regard, paired-box gene 8 negativity represents a useful diagnostic biomarker for differentiating MPM from ovarian carcinoma. In addition, BRCA1-associated protein-1 (BAP1) loss is specific to MPM and allows it to be distinguished from both benign mesothelial lesions and ovarian serous tumors. Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has become an increasingly important therapeutic approach, while systemic therapies are still being developed. Histology, Ki-67, completeness of cytoreduction, age, sex, and baseline thrombocytosis are commonly used to optimize patient selection for CRS with HIPEC. Additionally, it is well recognized that, compared to other subtypes, an epithelial morphology is associated with a favorable prognosis, whereas baseline thrombocytosis predicts an aggressive biologicalbehavior. Platelets and other immunologic cytokines have been evaluated as potential novel therapeutic targets. Epigenetic modifiers, including BAP1, SETD2 and DDX3X, are crucial in mesothelial tumorigenesis and provide opportunities for targeted treatment. Overexpression of the closely interacting phosphoinositide 3-kinase (PI3K) and the mammalian target of rapamycin (mTOR) pathways appears crucial in regulation of the malignant phenotype. The use of targeted therapies with PI3K-mTOR-based inhibitors requires further clinical assessment as a novel approach.

Peritoneal Metastases from Malignant Mesothelioma

Diffuse malignant peritoneal mesothelioma (MPM) is a rare cancer that is ultimately fatal in almost all afflicted individuals. Morbidity and mortality from MPM is due to its propensity to progress locoregionally within the abdominal cavity. Patients with MPM most commonly present with nonspecific abdominal symptoms that usually lead to diagnosis when the condition is relatively advanced. MPM is considered a chemotherapy-resistant malignancy.

Malignant Peritoneal Mesothelioma: National Practice Patterns, Outcomes, and Predictors of Survival

PURPOSE

This study of a large, contemporary national database evaluated management patterns, outcomes, and prognostic factors of malignant peritoneal mesothelioma (MPM) in the USA.

METHODS

The National Cancer Data Base was queried for newly diagnosed nonmetastatic MPM. Patients were divided into five cohorts: observation, chemotherapy alone, cytoreductive surgery (CRS) alone, CRS/chemo [referring to any non-hyperthermic intraperitoneal chemotherapy (HIPEC) chemotherapy], and CRS/HIPEC. Statistics included multivariable logistic regression, Kaplan-Meier analysis, and Cox proportional hazards modeling.

RESULTS

Of 1514 patients, 379 (25%) underwent observation, 370 (24%) received chemotherapy only, 197 (13%) CRS alone, 352 (23%) CRS/chemo, and 216 (14%) CRS/HIPEC. No major temporal trends in management were noted. Factors predictive of CRS administration included younger age, female gender, insurance status, residence in educated areas, living farther from treating institutions, and treatment at academic centers (p < 0.05 for all). Compared with epithelioid histology, those with sarcomatoid and biphasic histology were less and more likely to undergo CRS, respectively (p < 0.05 for both). In all CRS patients, 30- and 90-day mortality rates were 0.8 and 1.2%, respectively. At median follow-up of 50 months, median OS in the respective groups was 6, 17, 21, 52, and 61 months (p < 0.001). Poor prognostic factors included advanced age, male gender, uninsured/Medicaid insurance, and sarcomatoid/biphasic histology (p < 0.05 for all).

CONCLUSIONS

In the USA, MPM is treated using a wide variety of strategies. Many factors impact the type of treatment delivered, including age, sociodemographics, geography, histology, and facility type. Although these data do not imply causation, combined-modality management seems associated with the longest OS.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: morbidity and postoperative outcomes

BACKGROUND

Cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) represents a treatment option for peritoneal surface malignancies. Even if it has been reported that this new approach improved survival of selected patients, it is still associated with high morbidity and mortality rates.

METHODS

From October 1995 to December 2017, over 450 patients affected by peritoneal carcinomatosis (PC) underwent in our Institute CRS associated with HIPEC. For this preliminary analysis we considered 300 patients presenting PC of different origin: pseudomyxoma peritonei (PMP, N.=98), epithelial ovarian cancer (EOC, N.=87), peritoneal mesothelioma (DMPM, N.=49) and colorectal cancer (CRC, N.=66). Postoperative morbidity and mortality were studied in order to identify possible risk factors.

RESULTS

The morbidity rate was 36.3% in all procedures (109/300). According to the Clavien-Dindo Classification, 67 cases (22.3%) were associated with grade I-II complications and 35 cases (11.7%) with grade III-IV. Surgical and medical complication rates were 8.3% (25/300) and 11.3% (34/300), respectively. The mortality rate was 2.3%. Reoperation was needed in 28 patients (9.3%). The operative time, the number of anastomosis, of peritonectomy procedures, of visceral resections performed and the PCI value resulted the most statistically significant factors influencing postoperative morbidity and mortality.

CONCLUSIONS

The risks of perioperative morbidity and mortality after CRS and HIPEC are analogous to any other major gastrointestinal surgery. CRS and HIPEC should remain a treatment option for highly-selected patients in whom a curative or life prolonging treatment is a pursuit and should be performed in high volume specialized institutions.

Outcomes of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for peritoneal mesothelioma and predictors of survival

BACKGROUND

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) benefits selected patients with peritoneal mesothelioma. We present the outcomes of this treatment strategy in a UK peritoneal malignancy national referral centre.

METHODS

Observational retrospective analysis of data prospectively collected in a dedicated peritoneal malignancy database between March 1998 and January 2016.

RESULTS

Of 1586 patients treated for peritoneal malignancy, 76 (4.8%) underwent surgery for peritoneal mesothelioma. Median age was 49 years (range 21-73 years). 34 patients (45%) were female. Of the 76 patients, 39 (51%) had low grade histological subtypes (mostly multicystic mesothelioma), and 37 (49%) had diffuse malignant peritoneal mesothelioma (DMPM; mostly epithelioid mesothelioma). Complete cytoreduction was achieved in 52 patients (68%) and maximal tumour debulking (MTD) was performed in 20 patients (26%); the remaining 4 patients (5%) underwent a laparotomy with biopsy only. HIPEC was administered in 67 patients (88%). Median overall (OS) and disease-free survival (DFS) after CRS was 97.8 (80.2-115.4) and 58.8 (47.4-70.3) months, respectively. After complete cytoreduction, 100% overall survival was observed amongst patients with low-grade disease. Ki-67 proliferation index was significantly associated with survival outcomes after complete cytoreduction for DMPM and was an independent predictor of decreased survival.

CONCLUSION

With adequate patient selection (guided by histological classification and Ki-67 proliferation index) and complete cytoreduction with HIPEC, satisfactory outcomes can be achieved in selected patients with peritoneal mesothelioma.

Comparison of open and closed abdomen techniques for the delivery of intraperitoneal pemetrexed using a murine model

BACKGROUND AND OBJECTIVES

Pemetrexed is an appealing agent to use for cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). However, the optimal method of pemetrexed delivery still remains undefined. Using a murine model, we compared the use of open and closed abdomen techniques on the absorption of intraperitoneal (IP) pemetrexed in different compartments.

METHODS

Eleven Sprague-Dawley rats were submitted to a fixed dose of IP pemetrexed (1000 mg/m² ) at a perfusion temperature of 40°C during 25 min according to two techniques: open and closed. At the end of perfusion, samples in different compartments were harvested and the concentrations of pemetrexed were measured by high performance liquid chromatography.

RESULTS

Absorption of IP pemetrexed in portal and systemic blood was significantly higher using the open compared to the closed abdomen technique (93.17 vs 52.50 µg/mL, P < 0.001) and (76.26 vs 51.65 µg/mL, P < 0.001), respectively. No difference was found between the two techniques on the peritoneal tissue concentration of pemetrexed (18.07 vs 19.17 µg/g, P = 0.51).

CONCLUSION

Peritoneal absorption of pemetrexed is not modified by the use of either technique. However, systemic concentrations of pemetrexed increased using the open technique, suggesting it could increase systemic toxicity.

Clinical presentation, diagnosis, classification and management of peritoneal mesothelioma: a review

Peritoneal mesothelioma (PM) is an uncommon but a serious, and often, fatal primary peritoneal tumour, with increasing incidence worldwide. Conventional systemic chemotherapy, generally based on experience with pleural mesothelioma, usually has disappointing results considering PM as a terminal condition. Patients usually present with non-specific symptoms of abdominal distension and pain making the diagnosis challenging. As PM is confined to the abdomen for all, or much, of its clinical course, a multimodality treatment combining cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has emerged as a new standard of care, and has been reported to achieve promising survival outcomes and local disease control in selected patients with PM. This review updates the presentation, diagnosis, classification and treatment strategies for PM.

A Case of Obstructive Malignant Peritoneal Mesothelioma Treated With Postoperative Concomitant Cisplatin and Pemetrexed Chemotherapy

Malignant peritoneal mesothelioma is a rare disease with no established therapeutic method. A 79-year-old man underwent partial resection of the small intestine and right hemicolectomy for a bowel obstruction due to a mass in the small intestine and a submucosal tumor in the transverse colon. Malignant peritoneal mesothelioma was diagnosed from the excised specimen. After surgery, the patient received cisplatin and pemetrexed therapy, the standard treatment for malignant pleural mesothelioma. The progression of the remaining disseminated lesions was controlled for a year, and the patient led a satisfactory life without adverse events. He had a bowel obstruction 12 months after the surgery, and showed increased fluorodeoxyglucose uptake and new sites of high fluorodeoxyglucose uptake. Positron emission tomography/computed tomography was useful as the index of disease progression. Despite a second resection, the patient died 14 months after the first surgery.

Malignant peritoneal mesothelioma: a review

Mesothelioma is a malignancy of serosal membranes. It is most commonly encountered in the visceral pleura with the second most common location in the peritoneum. The diagnosis is very rare and has been linked to toxic exposure to industrial pollutants, especially asbestos. Malignant peritoneal mesothelioma (MPM) commonly presents with diffuse, extensive spread throughout the abdomen with rare metastatic spread beyond the abdominal cavity. Due to its rarity and nonspecific symptoms, it is usually diagnosed late when the disease burden is extensive. Because pleural mesothelioma is more common than MPM, most research has been on the pleural variant and extrapolated for MPM. While treatment advances have been made for MPM, the disease is universally fatal from either abdominal complications secondary to the spread of disease or starvation. Untreated, the life expectancy is less than a year. Cytoreductive surgery (CRS) with heated intraperitoneal chemotherapy (HIPEC) has become the mainstay of therapy with systemic therapies still being developed. We will review the epidemiology of MPM and discuss diagnostic and treatment strategies.

Indolent peritoneal mesothelioma: PI3K-mTOR inhibitors as a novel therapeutic strategy

Peritoneal mesothelioma (MPeM) is a scarce abdominal-pelvic malignancy that presents with non-specific features and exhibits a wide clinical spectrum from indolent to aggressive disease. Due to it being a rare entity, there is a lack of understanding of its molecular drivers. Most treatment data are from limited small studies or extrapolated from pleural mesothelioma. Standard treatment includes curative surgery or pemetrexed-platinum palliative chemotherapy. To date, the use of novel targeted agents has been disappointing. Described is the management of two young women with papillary peritoneal mesothelioma with widespread recurrence having received platinum-pemetrexed chemotherapy. Both patients obtained symptomatic and disease benefit with apitolisib, a dual phosphoinositide 3-kinase-mammalian target of rapamycin (PI3K-mTOR) inhibitor for subsequent relapses, with one patient having a partial response for almost 3 years. Both are alive and well 10-13 years from diagnosis.

CONCLUSION

These case presentations highlight a subgroup of rare MPeM that behave indolently that is compatible with long-term survival. This series identifies the use of targeted therapies with PI3K-mTOR-based inhibitors as a novel approach, warranting further clinical assessment. Development of prognostic biomarkers is essential to aid identify tumour aggressiveness, help stratify patients and facilitate treatment decisions.

Pharmacodynamics of Oxaliplatin-Derived Platinum Compounds During Hyperthermic Intraperitoneal Chemotherapy (HIPEC): An Emerging Aspect Supporting the Rational Design of Treatment Protocols

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) is used to treat peritoneal surface malignancies with application of cytostatic drugs such as oxaliplatin (OX) after cytoreductive surgery. Despite its increased use, evidence for optimal drug dosage, and notably duration of HIPEC, is scarce.

METHODS

In this study, OX distribution was comprehensively assessed in nine patients during HIPEC (300 mg OX/m² body surface area in Physioneal solution for 30 min). Oxaliplatin and its derivatives were measured in peritoneal perfusates over time by liquid chromatography coupled with mass spectrometry (LC-MS), and the resulting total platinum concentration in tissue was analyzed by atomic absorption spectrometry. Additionally, a novel impedance-based real-time cytotoxicity assay was used to evaluate the bioactivity of perfusates ex vivo.

RESULTS

Compared with amounts of OX expected in peritoneal perfusates by calculation, only 10-15% of the parent drug could be detected by LC-MS during HIPEC. Notably, the study additionally detected platinum compounds consistent with OX transformation, accounting for a further fraction of the applied drug. The cytotoxic properties of perfusates remained unchanged during HIPEC, with only a slight but significant attenuation evidenced after 30 min.

CONCLUSIONS

The bioactivity of peritoneal perfusates ex vivo is a useful parameter for evaluating the actual cytotoxic potential of OX and its derivatives used in HIPEC over time, overcoming important limitations and disadvantages associated with respective drug monitoring only. Ex vivo cytotoxicity assays may be a promising tool to aid guiding future standardization and harmonization of HIPEC protocols based on drug-mediated effects.

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.

Treatment of peritoneal surface malignancies with hyperthermic intraperitoneal chemotherapy-current perspectives

Peritoneal carcinomatosis (ptc) represents advanced malignant disease and has generally been associated with a grim prognosis. Peritoneal surface malignancy is often the major source of morbidity and mortality; it is of major concern in cancer management. Although ptc is categorized as metastatic disease, it represents a special disease pattern considered to be a locoregional disease limited to the abdominal cavity. The combination of cytoreductive surgery (crs) and intraoperative hyperthermic intraperitoneal chemotherapy (hipec) has successfully been used as locoregional treatment for selected patients with ptc from gastric, colorectal, and ovarian cancer; with mesothelioma; and with pseudomyxoma peritonei. In the prophylactic setting, hipec can also be used to prevent ptc in high-risk patients, and the first results of the "second-look" approach are promising. Patient selection-in which the risks of perioperative morbidity and mortality, which are analogous to those for any other major gastrointestinal surgery, are assessed-is of utmost importance. Those risks have to be weighed against the anticipated survival benefit, which depends mainly on tumour biology, extent of disease, and probability of achieving complete crs. The present review discusses the principles of crs and hipec, the most significant recent clinical data, and current perspectives concerning the application of this treatment modality in various malignancies. Ongoing trials and future directions are noted. It appears that the combination of crs and hipec is an indispensable tool in the oncologist's armamentarium.

Peritoneal mesothelioma: the site of origin matters

The etiology, gender distribution, pathology, natural history, and treatment options for mesothelioma (MM) differ substantially depending on the site of origin. Peritoneal mesothelioma (MPeM) is a rare disease, comprising only approximately 10% to 15% of the 2,500 cases of MM diagnosed in the United States each year. Patients with MPeM are younger than patients with pleural MM, and a higher proportion, mostly women, are long-term survivors. Most MPeM is caused by asbestos exposure. Germ-line mutations of BAP1 (BRCA associated protein 1) can predispose to MM, uveal melanoma, and potentially other cancers. MPeM can be challenging to diagnose, and cytology is rarely helpful. Review by an experienced pathologist using a panel of at least two positive and two negative immunohistochemical stains is essential. The three major pathologic subtypes are epithelial, sarcomatoid, and biphasic. Most cases are epithelial; the others have a dismal prognosis. Two indolent subtypes of borderline malignant potential-well-differentiated papillary mesothelioma and benign multicystic mesothelioma-are more common in the peritoneum and are treated surgically. In highly selected patients receiving treatment at experienced referral centers, an aggressive locoregional strategy that combines cytoreductive surgery to remove all gross disease and hyperthermic intraperitoneal chemotherapy to treat residual microscopic tumors yields a 3-year survival of 60% and a median survival approaching 5 years, far better than expected from historic controls. This approach also provides durable palliation of malignant ascites in nearly all patients. Pemetrexed is the only U.S. Food and Drug Administration (FDA)-approved systemic chemotherapy for pleural MM. Largely on the basis of data from pharmaceutical registry studies, the activity of pemetrexed-based chemotherapy appears to be similar in pleural MM and MPeM.

Repeat cytoreductive surgery with hyperthermic intraperitoneal chemotherapy: review of indications and outcomes

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is an established treatment option in selected patients with peritoneal dissemination from a variety of epithelial primaries. Even though a small proportion will be alive and potentially cured at 10 years, the majority will eventually develop recurrent disease. Repeat CRS/HIPEC is a valid consideration in a selected subpopulation of patients with isolated peritoneal recurrence. This review summarizes the data on patient selection, feasibility, limitations and outcomes of repeat CRS/HIPEC.

Diagnosis and management of patients with malignant peritoneal mesothelioma

Malignant peritoneal mesothelioma (MPM) is a rare neoplastic condition that arises, usually diffusely, from the serosal membranes of the abdominal cavity. MPM represents about 7% to 10% of all mesothelioma diagnoses and this translates into approximately 800 cases per year in the United States. The disease has variable tumor biology but progression, when it occurs, is almost always within the abdominal cavity. Although many patients can be successfully treated at initial presentation, the disease is almost always fatal in time. It afflicts men and women almost equally and the median age at presentation is 50 years. The diagnosis is made when a diffuse malignant process within the abdominal cavity is observed and a tissue sample reveals the characteristic histopathology and immunohistochemical profile of mesothelioma. Initial staging is usually via a cross sectional imaging study of the abdomen and pelvis making sure that the lower thorax is also assessed. If the disease burden and distribution is favorable then operative exploration, cytoreduction, and hyperthermic intraperitoneal chemotherapy (HIPEC) are considered first line treatment in selected patients. Systemic pemetrexed and cisplatin (or gemcitabine) have modest response rates that are of limited duration. Research advances with novel systemic or intraperitoneal agents hold promise.

Cytoreductive surgery and intraperitoneal chemotherapy: an evidence-based review-past, present and future

Peritoneal carcinomatosis (PC) has historically been considered a terminal condition with merely palliative treatment achieving a survival rate measured in months. Cytoreductive surgery (CyRS) and intraperitoneal chemotherapy (IPC) have emerged as potentially effective regional treatments with the potential for long-term survival in well-selected patients. The fundamentals of CyRS and IPC are patient selection and complete cytoreduction. Since there is now sufficient evidence for the superiority of CyRS and IPC to systemic chemotherapy alone in a highly select group of patients, surgeons and oncologists should be aware of this modality as a potential benefit for patients with PC. The aim of this report is to highlight cancer-specific evidence in the context of ongoing studies regarding the outcome of this treatment.

Outcomes of Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Mesothelioma: Experience of a Peritoneal Surface Malignancy Center

Diffuse malignant peritoneal mesothelioma (DMPM) is an uncommon malignancy, which can be difficult to treat. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have evolved as the treatment of choice when complete cytoreduction is to be achieved. This study reports the outcomes of CRS/HIPEC for peritoneal mesothelioma performed in a center for peritoneal surface malignancy. A retrospective analysis of a prospective database of 389 CRS/ HIPEC procedures identified 23 patients who underwent CRS/HIPEC for DMPM from 1999 to 2014. Gender, age at diagnosis, age at surgery, previous surgeries, follow-up time, peritoneal cancer index (PCI) score, completeness of cytoreduction (CC), pathology, and overall survival (OS) were analyzed. The univariate analysis was used to determine the prognostic value of age, gender, neoadjuvant chemotherapy, histopathology of the tumor, PCI, CC, and lymph node status on survival. Mean follow-up time from surgery was 31 months (range = 0.5–124). The median PCI score was 28, and 77 per cent had PCI ≥20. CC 0–1 was achieved in 65 per cent of cases. One- and 5-year actuarial OS rates from diagnosis were 86 per cent and 60 per cent, respectively. One- and 5-year actuarial OS from HIPEC was 70 per cent and 64 per cent, respectively. The univariate analysis showed that the CC was the only significant prognostic factor. Patients with DMPM may achieve long-term survival when treated with CRS/HIPEC. The CC is the most significant prognostic factor for long-term survival.

Peritoneal Mesothelioma: An Unusual Cause of High-Protein Ascites

We present a case illustrating the workup and diagnosis of peritoneal sarcomatous mesothelioma as an unusual etiology of intestinal obstruction and high-protein ascites in an otherwise healthy man. This rare disorder is diagnosed based on immunohistochemistry, which is necessary to differentiate it from other rare sarcomatous carcinomas. In many cases, localized disease can be treated to cure with surgery and intraperitoneal chemotherapy. Advanced disease is often treated for palliation of symptoms.

Predictive factors analysis for malignant peritoneal mesothelioma

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is an uncommon disease with a dismal prognosis and unclear natural history. The present study aims to assess potential prognostic factors and management of MPM.

METHODS

Clinical records of 39 patients with MPM between December 2003 and April 2014 were retrospectively reviewed. Overall survival was identified with Kaplan-Meier curves and Cox regression analysis.

RESULTS

Mean age of 39 patients was 55.0 years; asbestos exposure was recorded in two patients. Main presentations were abdominal distension, abdominal pain, and weight loss. Thrombocytosis, low serum albumin level, and anemia were principal laboratory abnormalities. Ascites, peritoneal cavity mass, and peritoneum thickening were the main signs on CT scans. Cytoreductive surgery (CRS) plus adjuvant therapies were performed in 22 patients, single chemotherapy in 13, and best supportive care in 4. Median survival time was 10.0 months after pathological diagnosis, with a 6-, 12-, 18-, and 24-month survival rate of 84.4, 31.6, 18.5, and 15.8 %, respectively. Significant prognostic factors were age, performance status (PS), abdominal pain, serum albumin level, thrombocytosis, and treatment strategy on univariate analysis, while only age, abdominal pain, and treatment strategy hold statistical significance on multivariate analysis.

CONCLUSIONS

Age ≤65 years, abdominal pain, and CRS plus adjuvant therapy are independent positive prognostic factors of MPM.

Advances in malignant peritoneal mesothelioma

BACKGROUND

Malignant mesothelioma is a rare, insidious, and aggressive tumor arising from the mesothelial surface of pleural and peritoneal cavities, the pericardium, or the tunica vaginalis, with an increasing incidence worldwide, high misdiagnosis rate, and overall negative prognosis. A total of 20% of all cases is peritoneum in origin.

METHODS

The present study is a review of literatures focusing on the advances in epidemiology, clinical presentations, radiological features, diagnosis, misdiagnosis, management, and prognostic factors of malignant peritoneal mesothelioma (MPM) occurred in the past decades.

RESULTS

Asbestos, SV40, and radiation exposures have been demonstrated to be correlated with the pathogenesis of MPM. The main presentations are abdominal distension and pain. Computed tomography (CT), magnetic resonance imaging (MRI), and positron-emission tomography (PET) play an important role in the preoperative imaging and staging. Definitive diagnosis is made on the basis of immunohistochemistry. Prognostic factors have been identified and verified. Negative indicators include advanced age, male gender, poor performance status, non-epithelial histology, and absence of surgery. The management of MPM has evolved from single chemotherapy to multimodality treatment of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), chemotherapy, radiotherapy, and immunotherapy. Promising results have been achieved after a combined treatment of CRS and HIPEC, with an elevated median survival time of 29.5-92 months and a 5-year survival rate of 39-63%.

CONCLUSIONS

CRS and HIPEC represent the standard treatment strategy for selected patients with MPM, and patients with unresectable tumors can benefit from the combined treatment of chemotherapy, radiotherapy, and immunotherapy.

Advances in the management of peritoneal mesothelioma

Malignant peritoneal mesothelioma (PM) is an infrequent disease which has historically been associated with a poor prognosis. Given its long latency period and non-specific symptomatology, a diagnosis of PM can be suggested by occupational exposure history, but ultimately relies heavily on imaging and diagnostic biopsy. Early treatment options including palliative operative debulking, intraperitoneal chemotherapy, and systemic chemotherapy have marginally improved the natural course of the disease with median survival being approximately one year. The advent of cytoreduction (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has dramatically improved survival outcomes with wide median survival estimates between 2.5 to 9 years; these studies however remain largely heterogeneous, with differing study populations, tumor biology, and specific treatment regimens. More recent investigations have explored extent of cytoreduction, repeated operative intervention, and choice of chemotherapy but have been unable to offer definitive conclusions. CRS and HIPEC remain morbid procedures with complication rates ranging between 30% to 46% in larger series. Accordingly, an increasing interest in identifying molecular targets and developing targeted therapies is emerging. Among such novel targets is sphingosine kinase 1 (SphK1) which regulates the production of sphingosine-1-phosphate, a biologically active lipid implicated in various cancers including malignant mesothelioma. The known action of specific SphK inhibitors may warrant further exploration in peritoneal disease.