Consensus statement on peritoneal mesothelioma

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.

Imaging of Malignant Pleural, Pericardial, and Peritoneal Mesothelioma

Malignant mesothelioma is a rare tumor arising from the mesothelial cells that line the pleura, pericardium, peritoneum, and tunica vaginalis. Imaging plays a primary role in the diagnosis, staging, and management of malignant mesothelioma. Multimodality imaging, including radiography, computed tomography (CT), magnetic resonance imaging (MRI), and F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), is used in a variety of scenarios, including diagnosis, guidance for tissue sampling, staging, and reassessment of disease after therapy. CT is the primary imaging modality used in staging. MRI has superior contrast resolution compared with CT and can add value in terms of determining surgical resectability in equivocal cases. MRI can further assess the degree of local invasion, particularly into the mediastinum, chest wall, and diaphragm, for malignant pleural and pericardial mesotheliomas. FDG PET/CT plays a role in the diagnosis and staging of malignant pleural mesothelioma (MPM) and has been shown to be more accurate than CT, MRI, and PET alone in the staging of malignant pleural mesothelioma. PET/CT can also be used to target lesions for biopsy and to assess prognosis, treatment response, and tumor recurrence.

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.

Prognostic role of radiological peritoneal cancer index in malignant peritoneal mesothelioma: national cohort study

Malignant peritoneal mesothelioma (MPeM) is a rare cancer of the mesothelial cells of the peritoneum. Computed tomography (CT) is considered the standard for first-line imaging of MPeM, diagnosis and risk stratification remains challenging. Peritoneal cancer index (PCI), as assessed by CT, is utilized in the prognostic assessment of other malignant intra-abdominal conditions; however, there is limited data concerning the utility of PCI in the diagnosis and workup of MPeM. We studied a retrospective cohort of all patients diagnosed with MPeM from 2000 to 2012 in Finland. CT and magnetic resonance imaging (MRI) were reviewed and scored by an experienced and blinded, board-certified abdominal radiologist. Additional clinical data and outcomes were obtained from Finnish Cancer Registry (FCR), the Workers' Compensations Center (WCC), and Statistics Finland (SF). Abdominal CT or MRI was available for 53 of 90 patients. The median radiographic PCI was 25. PCI score was correlated with overall survival (p = 0.004, Exp(B) = 1.064, 95% CI 1.020-1.110). PCI score ≥ 30 was associated with worse survival (p = 0.002), while PCI ≤ 19 was associated with improved overall survival (p = 0.001). Our study indicates that radiological PCI is prognostic in MPeM and should be assessed during radiographic workup and integrated into clinical decision-making.

Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) with Oxaliplatin, Cisplatin, and Doxorubicin in Patients with Peritoneal Carcinomatosis: An Open-Label, Single-Arm, Phase II Clinical Trial

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is an innovative approach for treating peritoneal carcinomatosis that applies chemotherapeutic drugs into the peritoneal cavity as an under-pressure airflow. It improves local bioavailability of cytostatic drugs as compared to conventional intraperitoneal chemotherapy. The aim of this study is to prove feasibility, efficacy and safety of this new treatment. Patients included in the analysis underwent at least two single port PIPAC procedures; drugs used were Oxaliplatin for colorectal cancers and Cisplatin + Doxorubicin for ovarian, gastric, and primary peritoneal cancers. The primary endpoint was the Disease Control Rate according to the RECIST (Response Evaluation Criteria in Solid Tumors) criteria. Secondary significant endpoints were overall and progression free survival, tumor regression on histology, and quality of life. Safety and tolerability were assessed according to the Common Terminology Criteria for Adverse Events 4. Sixty-three patients were enrolled in this trial. Forty patients (100 PIPAC) were eligible for analysis. Twenty patients were undergoing systemic chemotherapy. Fourteen patients reported an objective response (35%). Median overall survival was 18.1 months; median progression-free survival was 7.4 months. Minor morbidity was observed in seven procedures. Grade 3 complications occurred in two patients, and grade 4 in one patient submitted to reoperation. Single-port PIPAC is feasible, safe, and easy to perform. The combined treatment based on systemic chemotherapy and PIPAC does not induce significant hepatic and renal toxicity and can be considered a valid therapeutic option in patients with advanced peritoneal disease. Further studies on the use of PIPAC alone, possibly with different drug dosages, may define the real effectiveness of the procedure.

Cost analysis of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy and the risk factors for their increased cost in a public insurance health care system - Single centre study

INTRODUCTION

This study aimed to evaluate the costs of CRS and HIPEC and treatment of the related postoperative complications in the public healthcare system. We also aimed to identify the risk factors that increase the cost of CRS and HIPEC.

MATERIALS AND METHODS

We retrospectively evaluated 80 patients who underwent CRS and HIPEC between February 2016 and November 2018 in the Department of Surgery, University Hospital of Olomouc, Czech Republic. Intraoperative factors and postoperative complications were assessed. The treatment cost included the surgery, hospital stay, intensive care unit (ICU) admission, pharmaceutical charges including medication, hospital supplies, pathology, imaging, and allied healthcare services.

RESULTS

The postoperative morbidity rate was 50%, and the mortality rate was 2.5%. The mean length of hospitalisation and ICU admission was 15.44 ± 8.43 and 6.15 ± 4.12 for all 80 patients and 10.73 ± 2.93 and 3.73 ± 1.32, respectively, for 40 patients without complications, and 20.15 ± 13.93 and 8.58 ± 6.92, respectively, for 40 patients with complications. The total treatment cost reached €606,358, but the total reimbursement was €262,931; thus, the CRS and HIPEC profit margin was €-343,427. Multivariate analysis showed that blood loss ≥1.000 ml (p = 0.03) and grade I-V Clavien-Dindo complications (p < 0.001) were independently associated with increased costs.

CONCLUSION

The Czech public health insurance system does not fully compensate for the costs of CRS and HIPEC. Hospital losses remain the main limiting factor for further improving these procedures. Furthermore, treatment costs increase with increasing severity of postoperative complications.

Two-Stage Cytoreductive Surgery and Intraperitoneal Chemotherapy for Diffuse Malignant Peritoneal Mesothelioma: Predictors of Overall Survival in an Intention-to-Treat Series

PURPOSE

Cytoreductive surgery with intraoperative hyperthermic intraperitoneal chemotherapy is standard of care for diffuse malignant peritoneal mesothelioma (DMPM), but there is variability among institutions in the administration of adjuvant chemotherapy. Characterization of the largest series of DMPM patients treated at a single institution and identification of the demographic, disease, and treatment factors associated with overall survival were sought.

PATIENTS AND METHODS

All DMPM patients who underwent initial cytoreductive surgery with the intention to undergo intraperitoneal chemotherapy and a second-look operation from 1995 to 2016 at our institution were retrospectively reviewed. The primary endpoint was overall survival.

RESULTS

A total of 204 DMPM patients underwent initial cytoreduction. Median overall survival was 32 months from initial cytoreduction. Independent baseline prognostic factors of improved overall survival were female sex, age < 60 years, and epithelioid histology. Independent treatment factors associated with improved overall survival were attempted resection at initial operation, residual disease < 0.5 cm at the end of the initial operation, and dwell intraperitoneal chemotherapy.

CONCLUSIONS

Cytoreductive surgery with intraoperative and dwell intraperitoneal chemotherapy is a feasible approach for DMPM. Expanded access to these therapies may offer benefit to a larger population of patients. Demographic and operative parameters associated with overall survival in this large cohort are consistent with previous reports. In the context of this treatment protocol, dwell intraperitoneal chemotherapy is associated with longer overall survival.

Trends in peritoneal surface malignancies: evidence from a Czech nationwide population-based study

Background

The aim of this study is to identify the incidence trends of primary and secondary peritoneal surface malignancies in a representative Czech population.

Methods

Data were obtained from patients registered in the Czech National Cancer Registry between 1979 and 2016. The incidence rates were analyzed between 2012 and 2016. To observe the incidence trends, we analyzed the data from two time periods, 1979–2005 and 2006–2016. The analyzed data included age, sex, and the histological types and primary origins of the malignancies. The Cochrane-Armitage test for linear trends was used for verification of the null hypothesis. The significance level established for hypothesis testing was p = 0.05.

Results

Between 2012 and 2016, 230 patients with primary peritoneal tumors were identified and divided into the following groups according to their “International Statistical Classification of Diseases and Related Health Problems, 10th revision” codes: malignant neoplasm of specified parts of the peritoneum (C48.1); malignant neoplasm of the peritoneum, unspecified (C48.2); and malignant neoplasm of overlapping sites of the retroperitoneum and peritoneum (C48.8). Moreover, 549 primary tumors of the appendix (C18.1, encompassing all appendiceal malignancies) and 3137 secondary synchronous peritoneal carcinomatoses of other primary origins were documented. The age-adjusted incidence of primary peritoneal tumors in 2012–2016 was 4.36/year/1,000,000 inhabitants. The age-adjusted incidence of synchronous secondary peritoneal malignancies in 2014–2016 was 99.0/year/1,000,000 inhabitants. The diagnoses of primary peritoneal malignancies followed a stable trend between 1979 and 2016. However, the incidences of primary tumors of the appendix increased by 76.7%.

Conclusions

The data produced in our study ought to clarify the status of peritoneal surface malignancies in the Czech Republic, which can lead to improved planning and development of therapeutic interventions as well as physician training.

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.

Effect of Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy on Quality of Life in Patients with Peritoneal Mesothelioma

INTRODUCTION

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) is an accepted treatment for peritoneal mesothelioma. In this study, we evaluated QOL after HIPEC for peritoneal mesothelioma.

METHODS

This was a prospective study performed after HIPEC for peritoneal mesothelioma between 2002 and 2015. Patients completed QOL surveys, including the Short Form-36 (SF-36), Functional Assessment of Cancer Therapy + Colon (FACT-C), Brief Pain Inventory (BPI), and Center for Epidemiologic Studies Depression Scale (CES-D) preoperatively and at 3, 6, 12, and 24 months postoperatively.

RESULTS

Overall, 46 patients underwent HIPEC for peritoneal mesothelioma and completed QOL surveys. Mean age was 52.8 ± 13.8 years and 52% were male. Good preoperative functional status was 70%. Median survival was 3.4 years, and 1, 3, and 5-year survivals were 77.4, 55.2, and 36.5%, respectively. CES-D score decreased at 3 months postoperatively, but increased at 24 months (p = 0.014); SF-36 physical functioning scale decreased at 3 months but returned to baseline at 12 months (p = 0.0045); and the general health scale decreased at 3 months, then improved by 6 months (p = 0.0034). Emotional well-being (p = 0.0051), role limitations due to emotional problems (p = 0.0006), social functioning (p = 0.0022), BPI (p = 0.025), least pain (p = 0.045), and worst pain (p < 0.0001) improved. FACT-C physical well-being decreased at 3 months but returned to baseline at 6 months (p = 0.020), and total FACT-C score improved at 6 months (p = 0.052).

CONCLUSION

QOL returned to baseline or improved from baseline between 3 months and 1 year following surgery. Despite the risks associated with this operation, patients may tolerate HIPEC well and have good overall QOL postoperatively.

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: a review

Malignant peritoneal mesothelioma (MPM) is a very rare malignancy of the peritoneum and has a poor prognosis. Of all mesotheliomas, pleural mesothelioma is more common than MPM. In comparison to pleural mesothelioma, the link with asbestos exposure is weaker (33-50% vs. >80%), but it is still the best-defined risk factor. MPM spreads predominantly expansive rather than infiltrative and symptoms are related to tumor spread within the abdominal cavity. Often, MPM is encountered incidentally by diagnostic imaging or by surgery. Computed tomography scan is widely accepted as a first line modality in diagnostic imaging. In diagnostic histopathology, MPM presents some challenges. Firstly, adequate clinical information is of utmost importance to consider the possibility of the diagnosis of MPM. Furthermore, a few morphological subtypes and variants exist. The most sensitive immunohistochemical markers are calretinin (100%), WT1 (94%) and CK5/6 (89%). The malignant character of immunohistochemically demonstrated mesothelial cells is not always obvious. This paradigm somewhat changed with the advent of immunohistochemical demonstration of BAP1 (BRCA-1 associated protein 1). Loss of BAP1 expression supports a diagnosis of malignancy. The gold standard in treatment remains cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC). Targetable molecular pathways in MPM are being identified. An exciting finding was the demonstration of ALK rearrangements in a small subset of patients with MPM and it is hoped for that at least this small subgroup of patients could benefit from treatment with ALK inhibitors. First-generation tyrosine kinase inhibitors against epidermal growth factor receptor (EGFR) did not show any significant activity in MPM. In contrast, nintedanib, an angiokinase inhibitor, improved progression-free survival and bevacizumab, a humanized anti-VEGF antibody increased overall survival in patients with MPM, when administered in combination with cisplatin and pemetrexed. Ongoing immunotherapy trials will offer a possible new treatment.

Update on the management of malignant peritoneal mesothelioma

Malignant peritoneal mesothelioma (MPM) is a rare disease whose natural history is confined to the peritoneal space. Systemic chemotherapy has little impact on survival of patients with MPM. A surgical procedure with a goal of resection of all visible evidence of disease, called cytoreductive surgery (CRS) has been utilized in MPM patients. Also, regional chemotherapy with hyperthermic intraperitoneal chemotherapy (HIPEC) and normothermic intraperitoneal chemotherapy long-term (NIPEC-LT) have been effectively utilized in MPM patients. In the absence of CRS and HIPEC the median survival of MPM patients is approximately 1 year. The aggressive surgical approach plus regional chemotherapy has increased the median survival to more than 5 years. With NIPEC-LT added on, 70% 5-year survival has been reported. Knowledgeable patient selection for treatment is mandatory. The use of CRS, HIPEC and NIPEC-LT has greatly benefited patients with MPM. Global application of these treatments is indicated.

Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC) for the treatment of malignant mesothelioma

Background

Patients with recurrent malignant epithelioid mesothelioma (MM) after surgery and standard chemotherapy with cisplatin and pemetrexed have limited treatment options.

Methods

We performed a retrospective cohort study of patients with recurrent MM undergoing Pressurized IntraPeritoneal/Thoracal Aerosol Chemotherapy (PIPAC/PITAC) with doxorubicin 1.5 mg/m² and cisplatin 7.5 mg/m². Data were retrospectively collected in a prospective registry of patients undergoing PIPAC/PITAC. Study outcomes were microscopic tumor regression grade (TRG), survival and adverse events (v4.0 CTCAE).

Results

A total of 29 patients (m/f = 17/12) with MM with a mean age of 62.4 (range: 42 to 84) years were analyzed. A total of 74 PIPAC and 5 PITAC procedures were performed. The mean number of PIPAC applications was 2.5 (range: 0 to 10) per patient. Twenty patients (69%) had > 2 PIPAC procedure and were eligible for TRG analysis. TRG 1 to 4 was observed in 75% (15/20) of patients. Major regression (TRG 3) or complete regression (TRG 4) was observed in 20% and 10%, respectively. PIPAC induced significant tumor regression in 51.7% (15/29) of patients with a cumulative effect after repetitive PIPACs (PIPAC #1 vs. PIPAC #2: p = 0.001; PIPAC #1 vs. PIPAC #3: p = 0.001; PIPAC #1 vs. PIPAC #4: p = 0.001). Postoperative CTCAE grade 4 complications were observed in two patients (6.9%) who had cytoreductive surgery (CC2) and intraoperative PIPAC. One patient (3.4%) died due to postoperative kidney insufficiency. After a follow up of 14.4 (95% CI: 8.1 to 20.7) months after the last PIPAC/PITAC application, median overall survival was 26.6 (95% CI: 9.5 to 43.7) months (from the first application).

Conclusion

After prior abdominal surgery and systemic chemotherapy, repetitive PIPAC applications are feasible and safe for patients with end-stage MM. Furthermore, PIPAC induces significant histological regression of malignant mesothelioma in the majority of patients. PITAC is feasible, but its safety and efficacy to control malignant pleural effusion remain unclear.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4363-0) contains supplementary material, which is available to authorized users.

Factors Associated with 60-Day Readmission Following Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy

INTRODUCTION

Readmission rates following surgery are subject to scrutiny in efforts to control health care costs. This study was designed to define the 60-day readmission rate following cytoreduction and HIPEC at a high-volume center and to identify factors associated with readmission.

METHODS

Patients who underwent complete cytoreduction and HIPEC at a single institution from August 2007 through June 2014 were identified from a prospectively maintained database. Multiple preoperative and operative factors were analyzed for their ability to predict 60-day readmission following surgery.

RESULTS

A total of 250 patients were identified. Forty patients (17%) experienced readmission within 60 days of surgery. The most common reasons for readmission were ileus/dehydration (12, 31%), deep space infection (8, 21%), and DVT/PE (6, 15%). Initial postoperative length of stay was longer for patients readmitted within 60 days (median 12 vs. 9 days, p = 0.013). Of categorical variables analyzed, including gender, histology, HIPEC agent, intraoperative transfusion, and individual procedures performed during cytoreduction, adjuvant systemic therapy, and postoperative morbidity, only Charlson comorbidity index CCI (odds ratio (OR) = 3.80 [1.68-8.60]) and stoma creation (OR = 6.04 [1.56-12.14]) were associated with 60-day readmission.

CONCLUSIONS

Few measurable variables are associated with readmission following cytoreduction and HIPEC. Patients with high CCI and those with stomas created at the time of CRS/HIPEC may be at increased risk of readmission within 60 days. Earlier or more frequent follow-up for high-risk patients should be considered as a strategy to reduce readmissions.

Management of Malignant Peritoneal Mesothelioma Using Cytoreductive Surgery and Perioperative Chemotherapy

Malignant peritoneal mesothelioma is a rare disease, with approximately 800 new patients per year in the United States. Its natural history is defined by progression restricted to the peritoneal space. In the past, patients with this disease had a limited lifespan of approximately 1 year. Numerous single-institution studies as well as a systematic review have reported median survival of 3 to 5 years with a combination of cytoreductive surgery and hyperthermic perioperative chemotherapy. These markedly improved survival statistics were achieved in experienced centers with 1% mortality and 20% morbidity rates. Data have shown that knowledgeable patient selection is required to prevent patients unlikely to benefit from undergoing these interventions. The conclusion is that patients with peritoneal mesothelioma can experience long-term progression-free survival or significant palliation with cytoreductive surgery plus hyperthermic perioperative chemotherapy. This management plan should be considered the standard of care for properly selected patients with malignant peritoneal mesothelioma at experienced centers around the world.

First-line chemotherapy with pemetrexed plus cisplatin for malignant peritoneal mesothelioma

BACKGROUND

Mesothelioma of peritoneal origin has wider variation in treatment outcomes than mesothelioma of pleural origin, likely because peritoneal mesothelioma comprises borderline malignant variants and aggressive malignant peritoneal mesothelioma (MPeM). This study retrospectively evaluates the efficacy of first-line systemic pemetrexed and cisplatin chemotherapy in MPeM.

RESEARCH DESIGN AND METHODS

Twenty-four patients with histologically proven MPeM were treated with pemetrexed plus cisplatin as a first-line systemic chemotherapy. The response was evaluated radiologically according to standard Response Evaluation Criteria In Solid Tumors (RECIST) criteria. Twenty-two patients underwent ¹⁸F-fluorodeoxyglucose positron emission tomography/(FDG-PET)/computed tomography(CT) at baseline, and 13 were eligible for metabolic assessment.

RESULTS

Two complete responses and 9 partial responses were achieved. Overall response rate and disease control rate were 45.8% and 91.7%, respectively. Median progression-free survival and median overall survival were 11.0 months and 15.8 months, respectively. Wet- type MPeM had significantly longer survival (40.9 months median) than other clinical types (15.5 months) (P = 0.045). The baseline maximum standardized uptake value in 22 patients was 8.93 (range, 2.5-16.77).

CONCLUSIONS

Systemic pemetrexed plus cisplatin is active for MPeM. Disparity with the outcome of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) needs to receive more emphasis, since peritoneal mesothelioma has a 5-year survival rate of 50%.

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.

Normothermic intraperitoneal chemotherapy long term (NIPEC-LT) in the management of peritoneal surface malignancy, an overview

Background

Peritoneal metastases from gynecologic and gastrointestinal cancer is of increasing interest to surgical and medical oncologists because of newly recognized benefits of treatment. In contrast to prior outcomes, prolonged disease-free survival and cure have been reported.

Methods

To date, the benefits are to use complete surgical removal of the peritoneal metastases combined with hyperthermic intraperitoneal chemotherapy (HIPEC) delivered in the operating room. To supplement the local-regional control, normothermic intraperitoneal chemotherapy used long term (NIPEC-LT) and delivered by an intraperitoneal port has been explored.

Results

In three high grade malignancies with the preponderance of cytoreductive surgery (CRS) and HIPEC treatment failures within the peritoneal space, NIPEC-LT has been favorably reported in the oncology literature. In ovarian cancer and malignant peritoneal mesothelioma the NIPEC-LT is used an adjuvant treatment in an attempt to preserve a surgical complete response of CRS. In gastric cancer, NIPEC-LT is given as a neoadjuvant treatment with responders going on to radical surgical resection. Responses are monitored by laparoscopy.

Conclusions

This overview highlights benefits of NIPEC-LT in three diseases where benefits from CRS and HIPEC have been recognized but that local-regional failures persist. Improved results with NIPEC-LT have been reviewed for ovarian cancer, gastric cancer, and peritoneal mesothelioma.

Long-term regional chemotherapy for patients with epithelial malignant peritoneal mesothelioma results in improved survival

PURPOSE

Malignant peritoneal mesothelioma (MPM) is a rare disease with about 300 new cases per year in the USA. Its natural history is described as local progression within the peritoneal space in the absence of liver metastases or systemic disease.

METHODS

Cytoreductive surgery (CRS) is a series of peritonectomy procedures and visceral resections with a goal of complete removal of all visible disease from the abdomen and pelvis. Over 20 years, three protocols investigating increasing efficacy of additional chemotherapy treatments added to CRS have been initiated. Initially, hyperthermic perioperative chemotherapy (HIPEC) with doxorubicin and cisplatin was used in the operating room. Then, early postoperative intraperitoneal chemotherapy (EPIC) with paclitaxel was added for the first 5 days after CRS. The third protocol employed HIPEC, then EPIC, and then long-term intraperitoneal (IP) paclitaxel or IP pemetrexed plus intravenous (IV) cisplatin as a adjuvant normothermic intraperitoneal chemotherapy (NIPEC).

RESULT

The 5-year survival of 42 patients treated with CRS and HIPEC was 44%, for 58 patients treated with EPIC and HIPEC was 52% and 29 patients who received HIPEC, EPIC, and NIPEC was 75% (p = 0.0374). Prognostic variables of age, gender, treatment administered, peritoneal cancer index (PCI) and completeness of cytoreduction were significant by univariate analysis and treatments administered and completeness of cytoreduction significant by multivariate analysis.

CONCLUSIONS

Long-term regional chemotherapy was associated with improved survival in patients with MPM. In this rare disease, additional phase 2 investigations are suggested.

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.

The prognostic significance of BAP1, NF2, and CDKN2A in malignant peritoneal mesothelioma

Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion for patients with malignant peritoneal mesothelioma has resulted in improved disease control and increased survival. Despite these results, there are significant perioperative risks associated with this aggressive procedure that necessitate consideration of prognostic markers during patient selection. The molecular pathogenesis of peritoneal mesothelioma remains relatively unknown, but extrapolation of findings from their pleural counterpart would suggest frequent alterations in CDKN2A, NF2, and BAP1. Homozygous deletions in CDKN2A portend a worse overall survival in peritoneal mesothelioma. However, the prevalence and prognostic significance of NF2 and BAP1 abnormalities has not been studied. Dual-color fluorescence in situ hybridization using CDKN2A and NF2 locus-specific probes and BAP1 immunohistochemistry identified homozygous CDKN2A deletions (n=25, 29%), hemizygous NF2 loss (n=30, 35%), and/or loss of BAP1 protein expression (n=49, 57%) in 68 of 86 (79%) peritoneal mesotheliomas. Homozygous CDKN2A deletions or hemizygous NF2 loss correlated with shorter progression-free survival (P<0.02) and poor overall survival (P<0.03). Moreover, the significance of these findings was cumulative. Patients harboring both homozygous CDKN2A deletions and hemizygous NF2 loss had a 2-year progression-free survival rate of 9% with a median of 6 months (P<0.01) and overall survival rate of 18% with a median of 8 months (P<0.01). By multivariate analysis, combined homozygous CDKN2A deletions and hemizygous NF2 loss was a negative prognostic factor for both progression-free survival and overall survival, independent of patient age, peritoneal cancer index, completeness of cytoreduction, and extent of invasion. In contrast, loss of BAP1 was not associated with clinical outcome. In summary, homozygous deletions in CDKN2A and hemizygous loss of NF2 as detected by fluorescence in situ hybridization would confer a poor clinical outcome and may guide future treatment decisions for patients with peritoneal mesothelioma.

Sonographic Evaluation and Diagnosis of Peritoneal Mesothelioma Resulting in Massive Intra-abdominal Ascites

Mesothelioma is most commonly thought of as a pathology of the lungs; however, in rare cases it may develop in other areas of the body. Vague symptoms and lack of visible tumors in the beginning stages of the disease can make this pathology difficult to diagnose when manifesting in locations other than the lungs. This case study presents a rare occurrence of peritoneal mesothelioma. Multiple imaging modalities typically play a role in the diagnosis of this pathology, including sonography and computed tomography. The case report highlights the diagnostic and therapeutic values sonography can offer for such pathology.

Prognostic significance of morphological growth patterns and mitotic index of epithelioid malignant peritoneal mesothelioma

AIMS

The prognostic significance of histological subtyping of epithelioid pleural mesotheliomas has been recently reported, but similar data are lacking for peritoneal mesotheliomas. The aim of this study was to investigate possible relationships between histological growth patterns of epithelioid peritoneal mesotheliomas, clinicopathological features, and patient outcome.

METHODS AND RESULTS

Eighty-four cases of chemotherapy-naive epithelioid peritoneal mesothelioma were classified into tubulopapillary, micropapillary, papillary, tubular, solid and trabecular growth patterns. Pathological features such as depth of invasion, lymphocytic host response, mitotic count, nuclear grade, lymphovascular invasion, lymph node metastasis and stromal desmoplasia were analysed. The most common histological patterns were solid (n = 37, 44%), tubulopapillary (n = 24, 29%), and micropapillary (n = 11, 13%). The overall median survival was 36 months. Patients with solid mesothelioma had shorter overall survival (median, 29 months) than patients with tubulopapillary and micropapillary growth patterns (median, 51 and 53 months, respectively; P = 0.053). A high mitotic index (>5 in 50 high-power fields) was found to be associated with poor survival (P < 0.03). A moderate to severe lymphocytic host response was associated with longer median survival (P = 0.13).

CONCLUSIONS

Our study highlights the prognostic importance of the solid growth pattern among diffuse epithelioid peritoneal mesotheliomas, and reaffirms mitotic index as a predictor of overall survival.

Evolution of management in peritoneal surface malignancies

Management of peritoneal surface malignancies has gradually evolved by the introduction of cytoreductive surgery in combination with intraperitoneal chemotherapy applications. Recently, peritoneal metastases of intraabdominal solid organ tumors and primary peritoneal malignancies such as peritoneal mesothelioma are being treated with this new approach. Selection criteria are important to reduce morbidity and mortality rates of patients who will experience minimal or no benefit from these combined treatment modalities. Management of peritoneal surface malignancies with this current trend is presented in this review.

Repeat cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for recurrent diffuse malignant peritoneal mesothelioma

INTRODUCTION

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has shown to improve survival outcomes for patients with diffuse malignant peritoneal mesothelioma (DMPM).

PATIENTS AND METHODS

This is a retrospective study of prospectively collected data of 44 consecutive patients with DMPM who underwent CRS and HIPEC by the same surgical team at St George Hospital in Sydney, Australia. A total of 58 operations were performed. Clinical data were divided according to the number of operation and HIPEC the patient had undergone (Group 1 = initial CRS and HIPEC; Group 2 = 2nd CRS and HIPEC; Group 3 included 3rd CRS and HIPEC; Group 4 = 4th CRS and HIPEC). A significant difference was defined as p < 0.05.

RESULTS

There were no significant differences in mortality and morbidity results among the four groups. The median survival for those who only had one operation was 22 months (95% confidence interval (CI) = 0-47.2), whereas the median survival for those who had a second operation was 62 months (95% CI = 22.9-101.1). However, such a difference did not translate into a statistical significance (p = 0.141).

CONCLUSION

We report an encouraging median survival of 62 months in patients who had recurrence of disease and had repeat CRS and HIPEC with similar morbidity and mortality with the initial operation. Due to the learning curve of this technique, patients with recurrent mesothelioma should be referred to specialised tertiary care centres for evaluation. Selected patients may experience prolonged survival after repeat CRS and HIPEC.

Malignant Peritoneal Mesothelioma in an Adolescent Male With BAP1 Deletion

Diffuse malignant peritoneal mesotheliomas in children are uncommon, aggressive tumors with a grave prognosis. We herein report the clinical, radiologic, and pathologic findings of a 16-year-old male. The adolescent presented with a history of abdominal pain, nausea and daily, nonbilious, nonbloody emesis for 3 weeks. Radiographic imaging suggested small bowel obstruction. The diagnostic work-up and differential diagnoses are discussed. Histologically, the tumor was composed of epithelioid cells with a papillary and glandular architectural pattern. A few glands appeared to produce mucinous material. Histochemistry revealed PAS diastase resistant mucin, an inconspicuous finding in diffuse malignant peritoneal mesothelioma. An extensive immunohistochemistry panel (calretinin, WT-1, D2-40, CK 7, CAM 5.2, CK 5/6, CEA, B72.3, CK 20, CD10, CD30, CD15, CD117, PLAP, S100, TFE3, and EMA) confirmed the diagnosis. Of special interest, BAP1 staining was cytoplasmic and consistent with 3p deletion detected by conventional cytogenetics. The ultrastructural analysis demonstrated long microvilli, desmosomes, and intercellular junctions which further supported the diagnosis.

Surgical treatment of peritoneal carcinomatosis: current treatment modalities

BACKGROUND

Selected patients with peritoneal surface malignancies (PSM) have been treated effectively by the combination of cytoreduction surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

PURPOSE

The purpose of this study is to summarize the treatment outcomes and general considerations regarding definitions and staging systems of current CRS and HIPEC modalities in malignant peritoneal mesothelioma and in secondary peritoneal malignancies such as peritoneal metastasis from appendiceal, colorectal, gastric, and epithelial ovarian cancers.

CONCLUSION

Disease progression within the peritoneal cavity has in the past been regarded as a terminal event. Accumulating evidence underlines the therapeutic potential and the acceptable morbidity and mortality rates of CRS and HIPEC in selected patients.

Peritoneal debulking/intraperitoneal chemotherapy-non-sarcoma

The combination of cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC) is widely practiced for appendiceal, colorectal, gastric, and ovarian cancers with isolated peritoneal metastasis as well as for primary peritoneal cancer. The aim of this report is to explain the rationale and available techniques for CRS and IPC, and to highlight disease-specific considerations that should be taken into account when evaluating potential candidates for CRS and IPC.

Clinical significance of serum angiopoietin-1 in malignant peritoneal mesothelioma

We have previously reported that angiopoietin-1 was correlated with pulmonary fibrosis. Here, we investigated the serum levels of angiopoietin-1 in patients with malignant peritoneal mesothelioma, which originate from mesenchymal cells similar to lung fibroblasts. We showed that patients with peritoneal mesothelioma had significantly higher serum levels of angiopoietin-1 in comparison with a population with a history of asbestos exposure without peritoneal mesothelioma, and the Kaplan-Meier method revealed a significant correlation between serum angiopoietin-1 levels and survival. This is the first report about the relationship between angiopoietin-1 and peritoneal mesothelioma.

Serum HMGB1 as a diagnostic marker for malignant peritoneal mesothelioma

BACKGROUND

Diffuse malignant peritoneal mesothelioma (DMPM) is an aggressive malignant tumor of mesothelial origin that shows a limited response to cytoreductive surgery along with intraperitoneal chemotherapy. Therefore, early diagnosis of DMPM is very important. Some researchers have previously reported that high-mobility group box 1 (HMGB1) was correlated with pulmonary fibrosis. DMPM involves the malignant transformation of mesothelial cells, which originate from mesenchymal cells, similar to lung fibroblasts. Here, we investigated serum levels of HMGB1 in patients with MPM and compared them with those of a population that had been exposed to asbestos without developing MPM.

STUDY

The serum concentrations of HMGB1 were measured in 13 DMPM patients and 45 individuals with benign asbestos-related diseases.

RESULT

We demonstrated that the patients with DMPM had significantly higher serum levels of HMGB1 compared with the population who had been exposed to asbestos but did not develop DMPM.

CONCLUSION

Our data suggest that serum HMGB1 concentration is a useful serum marker for DMPM.

Novel 1H-pyrrolo[2,3-b]pyridine derivative nortopsentin analogues: synthesis and antitumor activity in peritoneal mesothelioma experimental models

In this study, we describe the synthesis of new nortopsentin analogues, 1H-pyrrolo[2,3-b]pyridine derivatives and their biological effects in experimental models of diffuse malignant peritoneal mesothelioma (DMPM), a rare and rapidly fatal disease, poorly responsive to conventional therapies. The three most active compounds, 1f (3-[2-(5-fluoro-1-methyl-1H-indol-3-yl)-1,3-thiazol-4-yl]-1H-pyrrolo[2,3-b]pyridine), 3f (3-[2-(1H-indol-3-yl)-1,3-thiazol-4-yl]-1-methyl-1H-pyrrolo[2,3-b]pyridine), and 1l (3-[2-(5-fluoro-1-methyl-1H-indol-3-yl)-1,3-thiazol-4-yl]-1-methyl-1H-pyrrolo[2,3-b] pyridine), which were shown to act as cyclin-dependent kinase 1 inhibitors, consistently reduced DMPM cell proliferation and induced a caspase-dependent apoptotic response, with a concomitant reduction of the expression of the active Thr(34)-phosphorylated form of the antiapoptotic protein survivin. Moreover, the combined treatment of DMPM cells with 3f derivative and paclitaxel produced a synergistic cytotoxic effect, which was paralleled by an enhanced apoptotic response. In the mouse model, i.p. administration of 1f, 3f, and 1l derivatives was effective, resulting in a significant tumor volume inhibition of DMPM xenografts (range, 58-75%) at well-tolerated doses, and two complete responses were observed in each treatment group.

Patient selection for cytoreductive surgery in colorectal peritoneal carcinomatosis using serum tumor markers: an observational cohort study

OBJECTIVE

There were 2 objectives: first, to investigate how many patients were excluded from surgery on the basis of the radiological extent of the peritoneal carcinomatosis (PC) or the clinical examination; and second, to develop a score based primarily on serum tumor markers (STMs) that could predict short cancer-specific survival (<12 months).

BACKGROUND

Patient selection and prediction of prognosis is crucial for successful treatment of colorectal PC.

METHODS

All patients with colorectal PC referred for cytoreductive surgery and intraperitoneal chemotherapy (2005-2008) at Uppsala University hospital were included. Patients were divided into 2 groups-nonsurgery and surgery. Clinicopathological and laboratory parameters were collected in the surgery group. A Corep (COloREctal-Pc) score was developed using hazard ratios from histology, hematological status, serial serum tumor markers (STMs), and STM changes over time. Sensitivity, specificity, positive predicted value (PPV), and negative predicted value (NPV) were calculated in a second validating dataset (n = 24) with a survival cutoff of less than 12 months.

RESULTS

A total of 107 patients were included in the study, 42 in the nonsurgery group and 65 in the surgery group. In the nonsurgery group, 2 patients were excluded solely on the basis of the radiological extent of PC and 7 patients on clinical examination. The Corep score ranged from 0 to 18. A score of 6 or more showed a validated sensitivity of 80%, specificity 100%, PPV 1.0, and NPV 0.93.

CONCLUSIONS

Radiological extent of PC was not a main deciding factor for treatment decisions and had less impact than the clinical examination. The Corep score identified patients with short cancer-specific survival that may not be suitable for treatment.

Serum thioredoxin-1 as a diagnostic marker for malignant peritoneal mesothelioma

BACKGROUND

Diffuse malignant peritoneal mesothelioma (DMPM) is an aggressive malignant tumor of mesothelial origin that shows a limited response to cytoreductive surgery along with intraperitoneal chemotherapy. Therefore, diagnosing DMPM early is very important. Reactive oxygen species play an important role in asbestos toxicity, which is associated with the pathogenesis of DMPM growth. Thioredoxin-1 (TRX) is a small redox-active protein that demonstrates antioxidative activity associated with tumor growth. Here, we investigated the serum levels of TRX in patients with DMPM and compared them with those of a population that had been exposed to asbestos but did not have DMPM.

STUDY

The serum concentrations of TRX were measured in 15 DMPM patients and 34 individuals with benign asbestos-related diseases.

RESULTS

We demonstrated that the patients with DMPM had significantly higher serum levels of TRX than the population that had been exposed to asbestos but did not have DMPM.

CONCLUSIONS

Our data suggest that serum TRX concentration is a useful serum marker for DMPM.

[Epidural analgesia for surgical treatment of peritoneal carcinomatosis: a risky technique?]

BACKGROUND

To study the risks of haemodynamic instability, and the possible occurrence of spinal haematoma, meningitis and epidural abscess when epidural analgesia is performed for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

We retrospectively analyzed the data of 35 patients treated by HIPEC with oxaliplatin or cisplatin. An epidural catheter was inserted before induction of general anaesthesia. Postoperatively, a continuous epidural infusion of ropivacain, then a patient-controlled epidural analgesia were started.

RESULTS

The epidural catheter was used peroperatively before HIPEC in 12 subjects (34%), and after HIPEC in 23 subjects (66%). The median dose of ropivacain given peroperatively in the epidural catheter was 40 mg (30-75). Norepinephrin was used in two subjects (6%) peroperatively (median infusion rate 0.325 μg/kg per minute [0.32-0.33]), and in four subjects (11%) in the postoperative 24 hours. No spinal haematoma, meningitis or epidural abscess were noted. Five subjects (14%) had a thrombopenia or a prothrombin time less than 60% before catheter removal. Two subjects (6%) had a leukopenia before catheter removal. No thrombopenia or blood coagulation disorders were recorded the day of catheter removal.

CONCLUSION

In this series of 35 patients, the use of epidural analgesia for HIPEC does not seem to be associated with a worse risk of haemodynamic instability, spinal haematoma, meningitis or epidural abscess. HIPEC with platinum salt is not incompatible with the safety of epidural analgesia, with an optimized fluid management peroperatively and the following of perimedullary anesthesia practice guidelines.

Mucin-positive epithelial mesothelioma of the peritoneum: small bowel involvement

Mucin-positive epithelial mesothelioma has been reported in the peritoneum only once, and that mainly involved the stomach wall. We report the second peritoneal case and this is the first case mainly involving the small bowel wall. A 65-year-old man showed diffuse involvement from the duodenum to the ileum and metastatic masses in the left adrenal gland. Segmental resection of the small bowel was performed; 2 months later the patient died. Light microscopy showed diffusely anaplastic epithelioid cell proliferation and foci of glandular formation with granular mucinous materials in the cytoplasmic vacuoles or within glandular lumina. Histochemically, these mucin materials were PAS-positive and diastase-resistant. Immunohistochemically, the various mesothelial markers were positive, and a few adenocarcinoma markers were focally positive. Ultrastructurally, the tumor cells showed long slender microvilli on the apical surface, consistent with mesothelioma. Electron microscopy can play a decisive role in the case of ambiguous histochemical and immunohistochemical results.

Cyto-reductive Surgery combined with Hyperthermic Intra-peritoneal Chemotherapy for Peritoneal Surface Malignancies: current treatment and results

Cyto-reductive Surgery (CS) combined with Hyperthermic Intra-peritoneal Chemotherapy (HIPEC) as loco-regional treatment of Peritoneal Surface Malignancies (PSM) has increasingly gained acceptance in clinical practice. This review summarizes the more relevant studies on this topic. Indications, pre-operative work-up, technical aspects, outcome and future directions of this combined approach in the treatment of Peritoneal Surface Malignancies are discussed here and proposed in an informative and didactic manner.

Diffuse malignant peritoneal mesothelioma: systematic review of clinical management and biological research

Diffuse malignant peritoneal mesothelioma (DMPM) is an uncommon and locally aggressive tumor with poor prognosis. Currently, no standard therapy is available. The biology of this disease is still poorly understood. We performed a systematic search of relevant studies on clinical management and biological research of DMPM. Trials were selected using a predetermined protocol. The current evidence suggests that cytoreductive surgery (CRS) and perioperative intraperitoneal chemotherapy (PIC) results in improved survival. Biological understanding of DMPM is currently evolving.

Two-stage operative cytoreduction and intraperitoneal chemotherapy for diffuse malignant peritoneal mesothelioma: Operative morbidity and mortality in phase I and II trials

AIMS

The standard of care for diffuse malignant peritoneal mesothelioma involves operative cytoreduction and intraperitoneal chemotherapy. Most centers favor aggressive operative cytoreduction, accepting high morbidity and mortality. In our trials, patients underwent less extensive cytoreduction followed by prolonged intraperitoneal chemotherapy. Patients underwent a second cytoreduction with heated intraperitoneal chemotherapy. We hypothesized this would result in lower operative morbidity and mortality with similar survival.

METHODS

Hospital records, discharge summaries, microbiology, radiography, and office records were retrospectively reviewed to supplement a prospective database. 30-day morbidity and mortality were categorized, and classified according to the Clavien methodology.

RESULTS

47 first and 39 second operations were performed with 13% and 26% morbidity, respectively. Mortality was 2%. Infections comprised 59% of the morbidity. Inclusive of both operations, formal peritonectomy was performed in 16% of patients, resection of isolated lesions in less than half, and only 19% had a visceral organs other than the spleen resected. At the completion of the protocol, only 3% of patients had visible intraperitoneal disease. The mean total length of stay for both operations combined was 16 ± 23 days. Overall median survival was 54.9 months, and median survival for the epithelioid subtype was 70.2 months.

CONCLUSIONS

A two-stage cytoreduction with intraperitoneal chemotherapy offers median survival comparable to one-stage protocols, with relatively low morbidity, mortality, visceral resections and length of stay despite two operations. This series supports that our protocol is a feasible and safe approach.

Receptor tyrosine kinase and downstream signalling analysis in diffuse malignant peritoneal mesothelioma

Our aim was to assess the activation profile of EGFR, PDGFRB and PDGFRA receptor tyrosine kinases (RTK) and their downstream effectors in a series of cryopreserved diffuse malignant peritoneal mesothelioma (DMPM) surgical specimens to discover the targets for drug inhibition. We also made a complementary analysis of the cytotoxic effects of some kinase inhibitors on the proliferation of the human peritoneal mesothelioma STO cell line. We found the expression/phosphorylation of EGFR and PDGFRB in most of the tumours, and PDGFRA activation in half. The expression of the cognate ligands TGF-α, PDGFB and PDGFA in the absence of RTK mutation and amplification suggested the presence of an autocrine/paracrine loop. There was also evidence of EGFR and PDGFRB co-activation. RTK downstream signalling analysis demonstrated the activation/expression of ERK1/2, AKT and mTOR, together with S6 and 4EBP1, in almost all the DMPMs. No KRAS/BRAF mutations, PI3KCA mutations/amplifications or PTEN inactivation were observed. Real-time polymerase chain reaction revealed the decreased expression of TSC1 c-DNA in half of the tumours. In vitro cytotoxicity studies showed the STO cell line to be resistant to gefitinib and sensitive to sequential treatment with RAD001 and sorafenib; these findings were consistent with the presence of the KRAS mutation G12D in these cells although it was not detectable in the original tumour. Our results highlight the ligand-dependent activation and co-activation of EGFR and PDGFRB, as well as a connection between these activated RTKs and the downstream mTOR pathway, thus supporting the role of combined treatment with RTK and mTOR inhibitors in DMPM.