Malignant peritoneal mesothelioma: prognostic factors and oncologic outcome analysis

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.

Updates on grading mesothelioma

Mesothelioma is a rare disease with an historically poor prognosis. Over the past decade, a grading system has been developed that is a powerful prognostic tool in epithelioid mesothelioma. Grading of epithelioid mesothelioma is now required or strongly recommended by expert consensus, the College of American Pathologists, the World Health Organization, and the International Mesothelioma Interest Group. The original nuclear grading system for epithelioid mesothelioma, developed in the United States, split epithelioid mesotheliomas into three prognostic groups with marked differences in survival. Now, this three-tiered nuclear grading system has been combined with the presence or absence of necrosis to form the currently recommended two-tiered grading system of low- and high-grade epithelioid mesothelioma. This review will focus on the development of this grading system in mesothelioma, the grading system's shortcomings, and the application of the grading system to cytology specimens and other extra-pleural sites. Lastly, this review will briefly discuss alternative grading systems and future considerations.

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

BACKGROUND

Diffuse malignant peritoneal mesothelioma (DMPM) is a rare and aggressive primary peritoneal disease, with recommended treatment, in eligible patients, of a combination of complete cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). As treatment is multimodal, there is a wide heterogeneity of HIPEC protocols precluding clear comparisons. Standardization at an international level is required.

METHODS

The Peritoneal Surface Oncology Group International (PSOGI) designated a steering committee to produce consensus recommendations for HIPEC regimens, adapted to each etiology. The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology was used, based on a systematic review focused on main outcomes related to HIPEC regimens in DMPM patients and on the patient, intervention, comparator, and outcome (PICO) method to elaborate main questions. An opinion survey was added. Furthermore, a Delphi process was performed with voting from a panel of international experts.

RESULTS

Eleven questions were elaborated, including two for future research requirements and three to assess the HIPEC regimen preference of the panel. The level of evidence underlying questions was globally low. Overall, 75 (86%) and 67 (77%) of the 87 invited experts completed the vote at the first and second round, respectively. HIPEC following complete CRS was strongly supported by 88% of voters with no need to plan comparative studies with CRS alone for 61.2% of voters. Bi-drug regimens appeared to be preferred to mono-drug ones and cisplatin was globally favored. The opinion survey confirmed the combination of cisplatin and doxorubicin as the recommended regimen.

CONCLUSION

International consensus confirmed the indication of HIPEC following complete CRS in DMPM patients and recommended cisplatin-doxorubicin as the first-line HIPEC regimen.

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

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

Synchronous Pleural and Peritoneal Mesothelioma: a Case Report and Narrative Review

Malignant mesotheliomas most often affect the pleura and tend to spread locally within the originating cavity. Mesotheliomas are already rare diseases, and cases with synchronous pleural and peritoneal involvement are scarce in the literature. Mesothelioma in children is a rare disease representing only 0.9% of all mesotheliomas. They exhibit similar distribution and characteristics as mesotheliomas in adults and generally, a poor prognosis. Due to the rarity, there is no standardized treatment recommendation for children with mesothelioma. Though the malignant mesothelioma tends to spread locally within the originating cavity, pleuM have been reported to metastasize into the peritoneal cavity and vice versa. As there are only few studies concerning the metastatic spread of mesothelioma, it is difficult to define a precise incidence and risk factors for patients to develop metastases of the other mesothelium. There is no standardized therapeutic recommendation for patients with synchronous pleuM and perM. Our patient proved to profit from a radical two-stage surgical approach in combination with locoregional chemotherapy; she showed no sign of tumor recurrences 9 years after tumor resection. In conclusion, clinical studies are needed to confirm the benefit of this treatment and to determine its limitations and selection criteria.

Caregivers of patients with malignant pleural mesothelioma: who provides care, what care do they provide and what burden do they experience?

PURPOSE

There are limited data on the impact of caregiving for patients with malignant pleural mesothelioma (MPM) on the caregiver. We aimed to identify the demographic characteristics of these caregivers, the caregiving activities they perform and how caregiving burden impacts their work productivity and overall activity.

METHODS

This cross-sectional study collected data from caregivers of patients with MPM across France, Italy, Spain and the United Kingdom January-June 2019. Caregiver demographics, daily caregiving tasks and the impact of caregiving on physical health was collected via questionnaire. The Zarit Burden Interview (ZBI) was used to assess caregiver burden and the Work Productivity and Activity Impairment questionnaire (WPAI) assessed impairment at work and during daily activities. Analyses were descriptive.

RESULTS

Overall, 291 caregivers provided data. Caregivers were mostly female (83%), living with the patient (82%) and their partner/spouse (71%). Caregivers provided over five hours of daily emotional/physical support to patients. ZBI scores indicated 74% of caregivers were at risk of developing depression. Employed caregivers had missed 12% of work in the past seven days, with considerable presenteeism (25%) and overall work impairment (33%) observed. Overall, the mean activity impairment was 40%.

CONCLUSION

Caregivers provide essential care for those with MPM. We show caregiving for patients with MPM involves a range of burdensome tasks that impact caregivers' emotional health and work reflected in ZBI and WPAI scores. Innovations in the management of MPM must account for how caregivers may be impacted and can be supported to carry out this important role.

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).

The contemporary management of peritoneal metastasis: A journey from the cold past of treatment futility to a warm present and a bright future

Peritoneal metastasis (PM) is often regarded as a less frequent pattern of spread; however, collectively across all spectra of primary tumors, the consequences of PM impact a large population of patients annually. Unlike other modes of metastasis, symptoms at presentation or during the treatment course are common, representing an additional challenge in the management of PM. Early efforts with chemotherapy and incomplete surgical interventions transiently improved symptoms, but durable symptom control and survival extension were rare, which established a perspective of treatment futility for PM through most of the 20th century. Notably, the continued development of better systemic therapy combinations, optimization of cytoreductive surgery (CRS), and rigorous investigation of combining regional therapy-specifically hyperthermic intraperitoneal chemotherapy-with CRS, have resulted in more effective multimodal treatment options for patients with PM. In this article, the authors provide a comprehensive review of the data establishing the contemporary approach for tumors with a high frequency of PM, including appendix, colorectal, mesothelioma, and gastric cancers. The authors also explore the emerging role of adding hyperthermic intraperitoneal chemotherapy to the well established paradigm of CRS and systemic therapy for advanced ovarian cancer, as well as the recent clinical trials identifying the efficacy of poly(adenosine diphosphate ribose) polymerase maintenance therapy. Finally, recent data are included that explore the role of precision medicine technology in PM management that, in the future, may help further improve patient selection, identify the best systemic therapy regimens, detect actionable mutations, and identify new targets for drug development.

FDG PET/CT for Staging and Restaging Malignant Mesothelioma

Malignant mesothelioma is an aggressive tumor originating from the mesothelial cells and presenting in general with a very poor prognosis. The pleural localization represents the prevailing disease site, while peritoneal involvement is commonly rare. The WHO classifies mesotheliomas into epithelioid, biphasic, and sarcomatoid histotypes, having diverse outcome with the sarcomatoid or biphasic forms showing the poorest prognosis. Given the peculiar rind-like pattern of growth, mesothelioma assessment is rather challenging for medical imagers. Conventional imaging is principally based on contrast-enhanced CT, while the role of functional and metabolic imaging is regarded as complementary. By focusing essentially on the staging and restaging role of [18F]FDG PET/CT in malignant mesotheliomas, the present review will summarize the available data present in literature and provide some hints on alternative imaging and future perspectives. Given the prevailing incidence of pleural disease, the majority of the information will be addressed on malignant pleural mesothelioma, although a summary of principal characteristics and imaging findings in patients with peritoneal mesothelioma will be also provided.

Clinical-pathological characteristics and prognostic factors for malignant peritoneal mesothelioma in the elderly

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is a rare disease characterized by atypical symptoms, difficult diagnosis, variable course and poor prognosis, and it develops mainly in elderly individuals. The authors aimed to identify the clinical-pathological characteristics, prognosis, and prognostic factors in elderly MPM patients.

METHODS

From the National Cancer Institute Surveillance Epidemiology End Results (SEER) database, 1492 patients with MPM from 1975 to 2016 were selected and divided into the elderly group (≥ 65) and the adult group (< 65). We compared the clinical-pathological characteristics and treatment methods of the elderly group (N = 665) and the adult group (N = 827). At the same time, we analysed specific selected clinicopathological parameters and prognostic factors for elderly MPM patients.

RESULTS

Compared with the adult group, the elderly group had higher percentages of male patients (P = 0.017) and white patients (P = 0.043) and lower proportions of insured patients (P < 0.001) married patients (P < 0.001), patients with peritoneal tumours (P = 0.006) and patients who underwent surgery (P < 0.001) and chemotherapy (P < 0.001). There was a significant difference in the differentiation grade between the two groups (P = 0.003). Elderly patients had a shorter median survival time than adult patients (6 months vs. 19 months). Uninsured (hazard ratio (HR): 5.187, P = 0.005), sarcomatoid type (HR 3.913, P < 0.001), poorly differentiated (HR 3.900, P < 0.001), distant metastasis (HR 1.735, P = 0.001), no cancer-directed surgery (HR 1.733, P < 0.001), and no chemotherapy (HR 1.532, P < 0.001) were independently associated with poorer prognosis in elderly MPM patients.

CONCLUSION

Compared with adult patients, elderly MPM patients had a higher male ratio, poor differentiation and relatively conservative treatment. The cancer-specific survival (CSS) rate of elderly MPM patients was significantly lower than that of adult patients. Insurance status, histology type, differentiation grade, stage, surgery status, and chemotherapy status were all independent prognostic factors for elderly MPM patients.

Key factors for successful cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy to treat diffuse malignant peritoneal mesothelioma: results from specialized peritoneal cancer center in China

OBJECTIVES

To investigate independent factors for the efficacy and safety of cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) for the treatment of diffuse malignant peritoneal mesothelioma (DMPM).

METHODS

The clinical database of 110 DMPM patients treated with CRS + HIPEC at our hospital was retrospectively analyzed. Independent prognostic factors were screened using univariate and multivariate analyses and the safety of the perioperative period was evaluated based on adverse events.

RESULTS

Among the 110 patients with DMPM, 34 (30.9%) had a peritoneal cancer index (PCI) < 20 and 76 (69.1%) had PCI ≥20; 59 (53.6%) patients achieved completeness of cytoreduction (CC) 0/1 and 51 (46.4%) cases achieved CC 2/3. At the median follow-up of 43.3 (95%CI: 37.3-49.4) months, 48 (43.6%) patients were still alive and 62 (56.4%) patients died. The median overall survival was 32.6 months. Serious adverse events (SAEs) occurred in 41 patients (37.3%) and the perioperative mortality rate was 2.7%. Univariate analysis identified nine prognostic factors: Karnofsky performance status score, perioperative tumor markers, PCI, red blood cell infusion, pathological type, vascular tumor emboli, lymphatic metastasis, Ki-67 index, and perioperative SAEs (all p < 0.05). Multivariate analysis identified four independent prognostic factors: pathological type (p = 0.007), vascular tumor emboli (p = 0.044), Ki-67 index (p = 0.044), and SAEs (p = 0.004).

CONCLUSIONS

CRS + HIPEC for DMPM treatment resulted in prolonged survival with acceptable safety. Tumor pathology and SAEs are key factors for successful CRS + HIPEC.

Early Postoperative Extubation is Associated with Shorter Hospitalization and Improved Short-Term Survival in Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is associated with significant operative time, hospital resources, and morbidity. We examine factors associated with hospital length of stay (LOS) and early overall survival (OS) after CRS/HIPEC.

MATERIALS AND METHODS

Patients who underwent CRS/HIPEC were evaluated for factors associated with LOS. Institutional learning curve influence was addressed by comparing early vs late cohorts. Variables with P < .200 after univariate analysis were considered for inclusion in multivariate linear regression modeling. Independent factors associated with OS were evaluated using the Kaplan-Meier method.

RESULTS

Seventy patients underwent CRS/HIPEC (mean age 52.3 years, 64.3% female, and 68.6% Caucasian). Presence of any surgical complication was found in 26 (37.1%), 28 (40%) remained intubated postoperatively, and the mean Peritoneal Carcinomatosis Index (PCI) score was 14.4 (±10.4). Mean intensive care unit and hospital LOS were 2.9 days (±2.3) and 9.6 days (±3.6), respectively. After adjusting for covariates, only shorter time to postoperative ambulation (regression coefficient .92, P = .001) and early extubation (regression coefficient -1.90, P = .018) were associated with decreased hospital LOS on multivariate analysis. Immediate postoperative extubation conferred an independent early survival benefit on Kaplan-Meier analysis (mean OS 714.8 vs 473.4 days, P = .010). There was no difference in hospital LOS or OS between early and late cohorts.

CONCLUSION

Early postoperative extubation and shorter time to ambulation are associated with decreased hospital LOS. Moreover, CRS/HIPEC patients extubated immediately postoperatively have an early survival benefit. Every effort should be made to achieve early postoperative extubation and mobilization in CRS/HIPEC patients.

Survival Outcomes for Malignant Peritoneal Mesothelioma at Academic Versus Community Hospitals

BACKGROUND

Malignant peritoneal mesothelioma is a rare disease with poor outcomes. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy is the cornerstone of therapy. We aim to compare outcomes of malignant peritoneal mesothelioma treated at academic versus community hospitals.

METHODS

This was a retrospective cohort study using the National Cancer Database to identify patients with malignant peritoneal mesothelioma from 2004 to 2016. Patients were divided according to treating facility type: academic or community. Outcomes were assessed using log-rank tests, Cox proportional-hazard modeling, and Kaplan-Meier survival statistics.

RESULTS

In total, 2682 patients with malignant peritoneal mesothelioma were identified. A total of 1272 (47.4%) were treated at an academic facility and 1410 (52.6%) were treated at a community facility. Five hundred forty-six (42.9%) of patients at academic facilities underwent debulking or radical surgery compared to 286 (20.2%) at community facilities. Three hundred sixty-six (28.8%) of patients at academic facilities received chemotherapy on the same day as surgery compared to 147 (10.4%) of patients at community facilities. Unadjusted 5-year survival was 29.7% (95% CI 26.7-32.7) for academic centers compared to 18.3% (95% CI 16.0-20.7) for community centers. In multivariable analysis, community facility was an independent predictor of increased risk of death (HR: 1.19, 95% CI 1.08-1.32, p = 0.001).

CONCLUSIONS

We demonstrate better survival outcomes for malignant peritoneal mesothelioma treated at academic compared to community facilities. Patients at academic centers underwent surgery and received chemotherapy on the same day as surgery more frequently than those at community centers, suggesting that malignant peritoneal mesothelioma patients may be better served at experienced academic centers.

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.

Value of cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy to treat malignant peritoneal mesothelioma

OBJECTIVE

To investigate the clinical efficacy of cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) for treating malignant peritoneal mesothelioma (MPM) and to assess the impact of this approach on patient prognosis.

METHODS

A retrospective analysis of 44 patients with MPM was performed. The control group (CNG, N = 23) was treated with CRS combined with postoperative intraperitoneal (IP) chemotherapy, while the observation group (OG, N = 21) was treated with CRS combined with HIPEC. The treatment efficacy, volume of blood loss, operation time, postoperative length of stay, and 3-year survival rate (SR) were compared, and the factors affecting the prognosis of MPM patients were analyzed by multivariate analysis.

RESULTS

The OG showed decreased volume of blood loss and operation time, while also showing increased overall treatment efficacy compared with the CNG. The SR in the OG was 65.22% compared with a rate of 33.33% in the CNG, and the 3-year SR in the OG was significantly higher than that in the CNG. Multivariate analysis revealed that tumor-node-metastasis (TNM) stage, Eastern Cooperative Oncology Group (ECOG) score, and treatment modality were independent risk factors for the prognosis of MPM patients.

CONCLUSION

CRS combined with HIPEC for MPM has a favorable treatment efficacy and prolongs the survival of MPM patients. Additionally, TNM stage, ECOG score, and treatment modality are independent risk factors for the prognosis of MPM patients.

A Palliative Approach to Management of Peritoneal Carcinomatosis and Malignant Ascites

In addition to severe, life-limiting complications such as malignant bowel obstruction, fistulae, and malignant ascites, peritoneal carcinomatosis frequently causes life-impacting symptoms such as pain, nausea, anorexia, cachexia, and fatigue. A variety of medical, interventional, and surgical therapies are now available for management of both complications and symptoms. Although surgery in this population is often associated with a relatively high risk of morbidity and mortality, operative intervention can offer effective palliative treatment in appropriately selected patients. Early involvement of palliative care specialists as part of a multidisciplinary team is essential to providing optimal, holistic care of patients with peritoneal carcinomatosis.

Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in the management of peritoneal surface malignancies - An evidence-based review

BACKGROUND

Traditionally, peritoneal surface malignancies (PSM) were considered terminal diseases because of their advanced nature, therefore, systemic chemotherapy was given with palliative intent only. As a result, very poor survival outcomes were observed. But with the introduction of complete Cytoreductive surgery (CRS) and Hyperthermic intraperitoneal chemotherapy (HIPEC), the scenario has changed dramatically.

METHODOLOGY

An objective electronic database search was performed in Pubmed, NLM Catalog, Google scholar, Bookshelf, and Pubmed Central published in the time period from 2000 till 2020. All the randomized studies were included. In the absence of randomized studies, both prospective and retrospective studies were included. The outcomes of HIPEC were measured in terms of median survival, disease-free survival, overall survival, complications and drug toxicities.

RESULTS

CRS and HIPEC are considered the standard of care for PMP and MPM even in the absence of level 1 evidence due to lack of an effective alternative treatment. In colorectal and gastric cancer, several phase-three trials are showing overall survival benefit in selected cases while there is a prophylactic and palliative role of HIPEC in gastric cancer. Three reported phase 3 trials showed positive results in ovarian cancer. In peritoneal sarcomatosis, the role of HIPEC is yet to be proven.

CONCLUSION

The patient selection is the key to the successful outcomes after HIPEC. HIPEC should be performed by the experienced surgeons in specialized centres with a strong critical care and intensive care support to reduce the morbidity and mortality. Ongoing trials and future directions will prove to be an indispensable arm in the oncological armamentarium.

Clinicopathological characteristics of primary peritoneal epithelioid mesothelioma of clear cell type: A case report

RATIONALE

Primary peritoneal epithelioid mesothelioma of clear cell type is an extremely rare entity composed of clear cytoplasm. It is challenging to diagnose because of the morphological resemblance to clear cell tumor.

PATIENTS CONCERNS

A 69-year-old male patient had swollen lymph nodes in the right inguinal region for 7 months and was constipated for 1 month.

DIAGNOSIS

The patient was diagnosed as peritoneal epithelioid mesothelioma of clear cell type based on computed tomography scan, pathology, immunohistochemistry, special staining and whole-exome sequencing. This patient harbored VHL gene alteration in exon 1 and homologous recombination defect (with a score of 45). This finding indicated that this patient might be sensitive to platinum-based therapy and Poly ADP-ribose Polymerase (PARP) inhibitor. This patient carried no microsatellite instability, a low level of tumor mutation burden, and a high extent of intratumoral heterogeneity. Eighteen neoantigens were detected.

INTERVENTIONS

The patient received surgery-based multidisciplinary treatment by integrating cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). HIPEC was administered with docetaxel 120 mg plus cisplatin 120 mg, at 43°C, for 60 minutes. After operation, the patient received intravenous (IV) chemotherapy with docetaxel 60 mg, pemetrexed 750 mg and cisplatin 100 mg, and then intraperitoneal (IP) chemotherapy with docetaxel 40 mg. The patient received interventional therapy of hepatic artery embolization for 5 times.

OUTCOMES

Regular follow-up was performed until Oct 14, 2020. The patient died 31.6 months later owing to incomplete intestinal obstruction.

LESSONS

Primary peritoneal epithelioid mesothelioma of clear cell type needs to be differentiated from a variety of clear cell tumors. This disease is characterized by specific genetic alteration. Whole-exome sequencing contributes to guide individualized therapy. CRS-HIPEC helps achieve long-term overall survival.

Malignant peritoneal mesothelioma: prognostic significance of clinical and pathologic parameters and validation of a nuclear-grading system in a multi-institutional series of 225 cases

Malignant peritoneal mesothelioma historically carried a grim prognosis, but outcomes have improved substantially in recent decades. The prognostic significance of clinical, morphologic, and immunophenotypic features remains ill-defined. This multi-institutional cohort comprises 225 malignant peritoneal mesotheliomas, which were assessed for 21 clinical, morphologic, and immunohistochemical parameters. For epithelioid mesotheliomas, combining nuclear pleomorphism and mitotic index yielded a composite nuclear grade, using a previously standardized grading system. Correlation of clinical, morphologic, and immunohistochemical parameters with overall and disease-free survival was examined by univariate and multivariate analyses. On univariate analysis, longer overall survival was significantly associated with diagnosis after 2000 (P = 0.0001), age <60 years (P = 0.0001), ECOG performance status 0 or 1 (P = 0.01), absence of radiographic lymph-node metastasis (P = 0.04), cytoreduction surgery (P < 0.0001), hyperthermic intraperitoneal chemotherapy (P = 0.0001), peritoneal carcinomatosis index <27 (P = 0.01), absence of necrosis (P = 0.007), and epithelioid histotype (P < 0.0001). Among epithelioid malignant mesotheliomas only, longer overall survival was further associated with female sex (P = 0.03), tubulopapillary architecture (P = 0.005), low nuclear pleomorphism (P < 0.0001), low mitotic index (P = 0.0007), and low composite nuclear grade (P < 0.0001). On multivariate analyses, the low composite nuclear grade was independently associated with longer overall and disease-free survival (P < 0.0001). Our data further clarify the interactions of clinical and pathologic features in peritoneal mesothelioma prognosis and validate the prognostic significance of a standardized nuclear-grading system in epithelioid malignant mesothelioma of the peritoneum.

Phase II Trial of Adjuvant Dendritic Cell Vaccine in Combination with Celecoxib, Interferon-α, and Rintatolimod in Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Metastases

BACKGROUND

Peritoneal metastases portend poor prognosis in the setting of standard chemotherapy. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) improves outcomes, but relapse is common. We report a phase II trial evaluating the safety and efficacy of adjuvant αDC1 vaccination with chemokine modulation (CKM) after CRS/HIPEC.

METHODS

Patients undergoing CRS/HIPEC for appendiceal cancer, colorectal cancer, or peritoneal mesothelioma were enrolled. In addition to standard adjuvant chemotherapy, patients received intranodal and intradermal injections of autologous tumor-loaded αDC1 vaccine. After each vaccine booster, patients received CKM over 4 days, consisting of celecoxib, interferon (IFN)-α, and rintatolimod.

RESULTS

Forty-six patients underwent CRS/HIPEC followed by αDC1 treatment, including 24 appendiceal primaries, 20 colorectal, and 2 mesotheliomas. DC maturation was successful, with 97% expressing HLA-DR and CD86. Tumor cell recovery from peritoneal tumors was challenging, resulting in only 17% of patients receiving the target dose of αDC1. The αDC1 and CKM regimen was well tolerated. CKM successfully modulated serum inflammatory cytokine and chemokine levels. Median progression-free survival (PFS) for appendiceal primaries was 50.4, 34.2, and 8.9 months for grade 1, 2, and 3 tumors, respectively, while median PFS for colorectal cancer was 20.5 and 8.9 months for moderately and poorly differentiated tumors, respectively.

CONCLUSIONS

Adjuvant autologous tumor antigen-loaded αDC1 vaccine and CKM is well tolerated. The mucinous nature of peritoneal metastases limits the feasibility of obtaining adequate autologous tumor cells. The improvement in median PFS did not meet our predefined thresholds, leading us to conclude that αDC1 vaccination is not appropriate for patients undergoing CRS/HIPEC for peritoneal metastases.

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.

Peritoneal Cancers and Hyperthermic Intraperitoneal Chemotherapy

Cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy is an aggressive, potentially curative approach used to treat locoregional disease associated with primary and secondary malignancies of the peritoneum. It involves resection of all macroscopic disease larger than 2.5 mm, followed by instillation of hyperthermic chemotherapy directly into the peritoneum for higher drug exposure to microscopic disease. In select patients with primary peritoneal mesothelioma, pseudomyxoma peritonei, colorectal adenocarcinoma, appendiceal adenocarcinoma, or ovarian cancer, with no extra-abdominal metastasis and limited involvement of the peritoneum, the procedure can be performed to increase overall survival.

Survivin expression as an independent predictor of overall survival in malignant peritoneal mesothelioma

Malignant peritoneal mesothelioma (MPeM) is an incurable cancer strongly associated with asbestos exposure and characterised by poor prognosis. The aim of the present study was to elucidate the prognostic and predictive value of CD146 and survivin expression in MPeM. Diagnostic biopsies from 60 patients with MPeM were collected and analysed for CD146, survivin and Ki-67 expression using immunohistochemistry. Complete clinical and follow-up information was obtained from patients' records. CD146 was expressed in 31/60 MPeM specimens and survivin in 34/60 specimens, with both expression levels being significantly associated with the Ki-67 labelling index (Ki-67LI). Kaplan-Meier and univariate Cox regression analyses revealed that a lower peritoneal cancer index (PCI), tumour-directed treatment, stage I, lower Ki-67LI and lower CD146 and survivin expression had a statistically positive effect on overall survival (OS). Cox regression analysis revealed that PCI [hazard ratio (HR)=1.99; 95% CI, 1.04–3.83; P=0.038], survivin (HR=1.47; 95% CI, 1.03–2.10; P=0.034) and treatment protocol including intraperitoneal chemotherapy (HR=0.28; 95% CI, 0.14–0.57; P=0.013) and systemic chemotherapy (HR=0.13; 95% CI, 0.04–0.42; P=0.013) retained independent prognostic significance for OS. All of these were included in the nomogram. Calibration curves showed good agreement between nomogram-predicted and observed survival. The C-index of the nomogram for predicting OS was 0.77. A lower PCI, intraperitoneal chemotherapy, systemic chemotherapy and a lower level of survivin were powerful prognostic markers in patients with MPeM. The proposed nomogram provides individual survival prediction for patients with MPeM.

Predictors and Outcomes of Surgery in Peritoneal Mesothelioma: an Analysis of 2000 Patients from the National Cancer Database

INTRODUCTION

Diffuse malignant peritoneal mesothelioma (DMPM) is a rare malignancy associated with poor outcomes. Recent reports have shown longer survival with radical surgery, usually combined with intraperitoneal chemotherapy. However, surgical interventions in these patients have not been extensively studied at a population level. The objective of this retrospective cohort study is to assess the prevalence of surgical and nonsurgical interventions for DMPM patients, the influence of surgery on survival outcomes, and the associations between demographic and clinical factors with treatments and outcomes.

METHODS

This study included adult patients diagnosed with DMPM from 2003 to 2014 and registered in the National Cancer Database (NCDB). The primary outcome was overall survival. Histologically confirmed mesothelioma was defined using International Classification of Diseases (ICD)-3 codes 9050/3, 9051/3, 90523, and 9053/3 and peritoneum as primary affected organ using ICD codes C17-19, C22-24, C26, C42, C48, and C76. Relationships between demographic and clinical variables, surgical treatments, and survival outcomes were evaluated using logistic and Cox modeling and log-rank tests.

RESULTS

A total of 2062 patients were identified, of whom 1055 (51%) did not receive any surgery while 701 (34%) received radical surgery. Patients receiving radical surgery had overall survival of 38.4 months compared with 7.1 months for patients without surgery (p < 0.001) and 41.8 months in patients who received both radical surgery and systemic chemotherapy.

CONCLUSIONS

Patients selected for and treated with radical surgery had significantly better overall survival compared with those receiving nonsurgical treatment. Patients newly diagnosed with DMPM should be evaluated for the possibility of receiving radical surgery.

Malignant Peritoneal Mesothelioma: Patterns of Care and Survival in the Netherlands: A Population-Based Study

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is a rare and aggressive disease. Recently, focus has shifted toward a more aggressive and multimodal treatment approach. This study aimed to assess the patterns of care and survival for MPM patients in the Netherlands on a nationwide basis.

METHODS

The records of patients with a diagnosis of MPM from 1993 to 2016 were retrieved from the Dutch Cancer Registry. Data regarding diagnosis, staging, treatment, and survival were extracted. Cox regression analyses and Kaplan-Meier survival curves were used to study overall survival.

RESULTS

Between 1993 and 2016, MPM was diagnosed for 566 patients. Overall, the prognosis was very poor (24% 1-year survival). The most common morphologic subtype was the epithelioid subtype (88%), followed by the biphasic (8%) and sarcomatoid (4%) subtypes. Surgical treatment has become more common in recent years, which most likely has resulted in improved survival rates. In this study, improved survival was independently associated with hyperthermic intraperitoneal chemotherapy (hazard ratio [HR], 0.33; 95% confidence interval [CI], 0.21-0.55) and surgery with adjuvant systemic chemotherapy (HR, 0.33; 95% CI, 0.23-0.48). Nonetheless, most patients (67%) do not receive any form of anti-cancer treatment.

CONCLUSION

This study indicated that MPM still is a rare and fatal disease. The survival rates in the Netherlands have improved slightly in the past decade, most likely due to more aggressive treatment approaches and increased use of surgery. However, most patients still do not receive cancer-directed treatment. To improve MPM management, and ultimately survival, care should be centralized in expert medical centers.

Identification of ALK Rearrangements in Malignant Peritoneal Mesothelioma

Importance

Malignant peritoneal mesothelioma is a rare, aggressive tumor arising from the peritoneal lining, induced by asbestos, therapeutic radiation, or germline mutations. Nevertheless, the molecular features remain largely unknown.

Objective

To investigate anaplastic lymphoma kinase (ALK) rearrangements in a large series of peritoneal mesothelioma and characterize the mutational landscape of these tumors.

Design, Setting, and Participants

We studied 88 consecutive patients (39 men, 49 women; median age 61, range 17-84 years) with peritoneal mesotheliomas diagnosed at a single institution between 2005 and 2015. We identified ALK-positive mesotheliomas by immunohistochemistry and confirmed ALK rearrangement by fluorescence in situ hybridization (FISH). In ALK-rearranged cases, we characterized the fusion partners using targeted next-generation sequencing of both tumor DNA and RNA. In select cases, we quantified asbestos fibers by combined scanning electron microscopy and x-ray spectroscopy. We also explored ALK rearrangement in a separate series of 205 patients with pleural mesothelioma.

Main Outcomes and Measures

Identification and characterization of novel ALK rearrangements and correlations with clinicopathologic characteristics.

Results

Anaplastic lymphoma kinase was positive by immunohistochemistry in 11 (13%) peritoneal mesotheliomas (focal weak in 8, diffuse strong in 3). In focal weak ALK-positive cases, no ALK rearrangement was detected by FISH or next-generation sequencing. In strong diffuse ALK-positive cases, FISH confirmed ALK rearrangements, and next-generation sequencing identified novel fusion partners ATG16L1, STRN, and TPM1. Patients with ALK-rearranged peritoneal mesotheliomas were women and younger than patients without ALK rearrangement (median age 36 vs 62; Mann-Whitney test, P = .02), but all other clinicopathologic characteristics (size of tumor nodules, histology, treatment, and survival) were not different. No asbestos fibers were detected in ALK-rearranged cases. Furthermore, loss of chromosomal region 9p or 22q or genetic alterations in BAP1, SETD2, or NF2 typically present in peritoneal mesothelioma were absent in the ALK-rearranged cases. All pleural mesotheliomas were ALK-negative by immunohistochemistry.

Conclusions and Relevance

We identified unique ALK rearrangements in a subset of patients with peritoneal mesothelioma, each lacking asbestos fibers, therapeutic radiation, and cytogenetic and molecular alterations typically found in these tumors. Identification of clinically actionable ALK rearrangements may represent a novel pathogenetic mechanism of malignant peritoneal mesothelioma with promise for targeted therapy.

Mesothelioma: Scientific clues for prevention, diagnosis, and therapy

Mesothelioma affects mostly older individuals who have been occupationally exposed to asbestos. The global mesothelioma incidence and mortality rates are unknown, because data are not available from developing countries that continue to use large amounts of asbestos. The incidence rate of mesothelioma has decreased in Australia, the United States, and Western Europe, where the use of asbestos was banned or strictly regulated in the 1970s and 1980s, demonstrating the value of these preventive measures. However, in these same countries, the overall number of deaths from mesothelioma has not decreased as the size of the population and the percentage of old people have increased. Moreover, hotspots of mesothelioma may occur when carcinogenic fibers that are present in the environment are disturbed as rural areas are being developed. Novel immunohistochemical and molecular markers have improved the accuracy of diagnosis; however, about 14% (high-resource countries) to 50% (developing countries) of mesothelioma diagnoses are incorrect, resulting in inadequate treatment and complicating epidemiological studies. The discovery that germline BRCA1-asssociated protein 1 (BAP1) mutations cause mesothelioma and other cancers (BAP1 cancer syndrome) elucidated some of the key pathogenic mechanisms, and treatments targeting these molecular mechanisms and/or modulating the immune response are being tested. The role of surgery in pleural mesothelioma is controversial as it is difficult to predict who will benefit from aggressive management, even when local therapies are added to existing or novel systemic treatments. Treatment outcomes are improving, however, for peritoneal mesothelioma. Multidisciplinary international collaboration will be necessary to improve prevention, early detection, and treatment.

Manejo del mesotelioma peritoneal maligno con citorreducción quirúrgica más quimioterapia hipertérmica intraperitoneal en el Instituto Nacional de Cancerología, Colombia: reporte de un caso y revisión bibliográfica

El mesotelioma peritoneal es una neoplasia que se origina en las células mesoteliales del peritoneo. Históricamente, la supervivencia de los pacientes con mesotelioma peritoneal maligno sin tratamiento, es menor de 12 meses y se considera una neoplasia resistente a la quimioterapia. La citorreducción quirúrgica y la quimioterapia regional administrada como quimioterapia hipertérmica intraperitoneal (Hyperthermic Intraperitoneal Chemotherapy, HIPEC) se asocia con mejor supervivencia a largo plazo. Se presenta el caso de un paciente con antecedentes de exposición al asbesto y con diagnóstico de mesotelioma peritoneal maligno de tipo epitelioide, que fue tratado con cirugía citorreductora más quimioterapia hipertérmica intraperitoneal en el Instituto Nacional de Cancerología con una supervivencia de un año libre de enfermedad.

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.

Genome-wide profiling reveals novel microRNAs in hand-spinning-specific chrysotile exposure

Aim: We aimed to explore miRNA expression profiles in hand-spinning chrysotile exposed workers and their potential influencing factors. Methods: miRNA array technique was applied to screen differentially expressed miRNAs between plasma samples from three exposed workers and three controls. Then, seven selected miRNAs were validated in 143 workers and 100 controls, and the potential influencing factors were revealed by multiple linear regression. Finally, the expression levels of those seven miRNAs were evaluated in human mesothelial cells (Met-5A) that were exposed to chrysotile at 5 μg·cm-2 for 8, 24 and 48 h, respectively. Results & conclusion: Hand-spinning chrysotile exposure can result in differential expression of miRNAs. Several of those miRNAs have positive correlations with asbestos exposure.

Testicular Mesothelioma: An Analysis of Epidemiology, Patient Outcomes, and Prognostic Factors

OBJECTIVES

To characterize demographic features, clinical characteristics, and oncologic outcomes of mesothelioma of the testis.

METHODS

A population based search was performed using the National Cancer Institute's SEER 18 database. Patients diagnosed with malignant mesothelioma of the male genital organs from 1973 to 2015 were identified. Data on patient age, race, tumor laterality, histologic subtype, tumor extent, tumor size, tumor grade, treatment, cause of death, and survival months was collected. Primary outcomes were overall survival (OS) and disease-specific survival (DSS).

RESULTS

A total of 113 patients with testicular mesothelioma were identified. The 5-year OS and DSS for all patients was 49% and 58%, and the 10-year OS and DSS was 33% and 45%, respectively. Biphasic mesotheliomas were associated with worse OS compared to general mesotheliomas and epithelioid subtypes (P = .043 and P = .039, respectively). Median survival time was not reached in patients with T1 disease while OS was 1.7 years and DSS was 1.8 years for patients with T4 disease (OS P = .002, DSS P <.001). Tumors greater than or equal to 4 cm were associated with worse OS and DSS (OS P = .025, DSS P = .047).

CONCLUSION

This rare malignancy has significant mortality, with poor survival associated with biphasic subtypes, higher disease stage, and a critical tumor size cutoff of 4 cm.

Management of Peritoneal Malignancies

Peritoneal malignancies may result in a widespread disease process, peritoneal carcinomatosis (PC), which has significant morbidity and mortality for patients afflicted by this disease. Dissemination into the peritoneum and throughout the abdomen can be due to a primary peritoneal cancer or other primary malignancies that have metastasized, including (but not limited to) colorectal cancer, gastric cancer, pancreatic cancer, appendiceal cancer, ovarian cancer, and mesothelioma. Patients with gastrointestinal (GI) or gynecologic malignancies with peritoneal carcinomatosis may have dismal survival due to a high disease burden within the abdominal cavity. Some studies suggest the average survival for patients with peritoneal carcinomatosis of colorectal origin is 18–48 months, for high-grade appendiceal adenocarcinoma 12–36 months, and for low-grade appendiceal neoplasms >60 months. As the understanding of peritoneal malignancies and peritoneal carcinomatosis evolved, it may now be acceptable to treat this as locoregional disease.

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.

IMP3 as a prognostic biomarker in patients with malignant peritoneal mesothelioma

Malignant peritoneal mesothelioma (MPeM) is an incurable cancer with poor prognosis, and several biomarkers have been suggested for screening of MPeM. The aim of our study was to evaluate the prognostic significances of IMP3 and Fli-1 in MPeM. Diagnostic biopsies of 44 MPeM patients were centrally collected and were immunohistochemically analyzed for expression of IMP3, Fli-1, and Ki-67. Labeling was assessed by 2 pathologists. Complete clinical information and follow-up were obtained from patients' records. Carcinomas expressed Fli-1 in 42 (95.5%) of 44 specimens, and IMP3 in 23 (52.3%) of 44 specimens. Spearman ρ analysis revealed that Fli-1 expression was related to both histologic type and Ki-67 labeling index (Ki-67LI; r = -0.500, P < .05; r = 0.358, P < .05), and IMP3 expression was related to Ki-67LI (r = 0.401, P < .05). A Kaplan-Meier analysis and univariate Cox regression analysis showed that tumor-directed treatment, a lower peritoneal carcinomatosis index, stage I, lower Ki-67LI, and lower level of IMP3 expression had a statistically significantly positive effect on overall survival; Fli-1 did not affect overall survival in the univariate analysis (hazard ratio [HR], 1.026; P = .904). A Kaplan-Meier analysis showed the correlation between IMP3-Fli-1 and overall survival, whereas univariate and multivariate Cox regression analyses did not confirm the correlation. Cox regression analysis revealed that IMP3 expression (HR, 2.311 [95% confidence interval, 1.190-4.486]; P = .013) and no tumor-directed treatment (HR, 0.189 [95% confidence interval, 0.086-0.416]; P = .000) retained independent prognostic significance, both with negative effect on OS. IMP3, along with tumor-directed treatment protocols, is a powerful prognosticator in patients with MPeM.

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.

Current Management and Future Opportunities for Peritoneal Metastases: Peritoneal Mesothelioma

PURPOSE

Diffuse malignant peritoneal mesothelioma (MPM) is a rare and ultimately fatal cancer that was first described just over a century ago. It is a diffuse malignancy arising from the mesothelial lining of the peritoneum; morbidity and mortality from MPM is due to its propensity to progress locoregionally within the abdominal cavity.

METHODS

The purpose of this article is to review the current state-of-the-science related to the diagnosis, staging, and treatment of MPM.

RESULTS

The condition afflicts men and women equally and the peak incidence is between 55 and 60 years of age although it can arise in the young and elderly. Patients afflicted with MPM most commonly present with nonspecific abdominal symptoms that usually lead to diagnosis when the condition is relatively advanced. Historically, median overall survival for MPM patients without treatment is < 1 year. The couplet of systemic pemetrexed and cisplatin has an overall response rate of approximately 25% and a median overall survival of approximately 1 year.

CONCLUSION

The available data, almost all retrospective in nature, have shown that in selected patients, operative cytoreduction (CRS) and regional chemotherapy administered as hyperthermic intraoperative peritoneal chemotherapy (HIPEC) or early postoperative intraperitoneal chemotherapy (EPIC) is associated with long-term survival. Studies on the molecular biology of MPM have yielded new insights relating to the potentially important role of the phosphoinsitide-3-kinase/mammalian target of rapamycin (PI3 K/mTOR) pathways and immune checkpoint inhibitors that may translate into new therapeutic options for patients with diffuse MPM.

Abdominal wall reconstruction after cytoreduction surgery-hyperthermic intraperitoneal chemotherapy

BACKGROUND

Cytoreduction surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) improve survival and decrease recurrence of peritoneal metastasis in a select population of patients. Abdominal wall resection is often needed to achieve complete CRS and the extent of abdominal wall resection may necessitate abdominal wall reconstruction (AWR). We sought to investigate if postoperative morbidity and mortality was increased in patients who underwent AWR with CRS-HIPEC (AWR group) compared to CRS-HIPEC without AWR (non-AWR group) and to identify if patient, tumor, and operative risk factors were associated with poor outcomes following AWR. We postulate that AWR is a safe and viable treatment option in appropriately selected patients with peritoneal disease.

METHODS

A retrospective chart review was conducted from 2012 to 2015. Demographics, comorbidities, intraoperative variables, and postoperative outcomes were analyzed and compared between the non-AWR group and the AWR group.

RESULTS

A total of 30 patients underwent CRS-HIPEC at our institution; 19 recruited in non-AWR group and 11 in the AWR arm. Median follow-up was 19.1 mo for the non-AWR group and 15.6 mo for AWR. Overall survival and complications were not significantly different between groups. Six patients in the non-AWR group and three patients in AWR group died during the follow-up period (32% versus 27%, P = 0.75). Grade III/IV Clavien-Dindo complications were similar in AWR compared to non-AWR group (64% versus 50%, P = 0.46) however estimated blood loss (1000 mL versus 450 mL, P = 0.01) and operative time (663 min versus 510 min, P = 0.02) were significantly increased in the AWR group.

CONCLUSIONS

The results of this study demonstrate that AWR is a safe and viable option and can improve wound closure and strength in select patient populations undergoing CRS-HIPEC. AWR is not associated with an increase in mortality or complication rate. Future studies will need larger sample sizes and randomization to identify patient and operative factors that increase morbidity with AWR and identify the ideal timing of AWR.

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.

Radiological predictors of complete cytoreduction in 59 patients with peritoneal mesothelioma treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy at a UK referral centre

OBJECTIVE

To assess the imaging features of peritoneal mesothelioma and identify key anatomical sites that aid patient selection for complete cytoreduction.

METHODS

Pre-operative imaging of 59 (32 males, 27 females) patients who underwent cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) for histologically proven peritoneal mesothelioma [36 malignant peritoneal mesothelioma, 23 cystic mesothelioma were reviewed. Imaging findings were correlated with surgical outcome. Best imaging predictors of complete cytoreduction, n = 22 and major tumour debulking, n = 12 were assessed.

RESULTS

Most patients (88.9%) had diffuse peritoneal disease with mean radiological peritoneal cancer index of 18 ± 12 (range 2-39). Disease in the lesser omentum (n = 10), porta hepatis (n = 8), perigastric area (n = 5), mesentery (n = 25), small bowel (n = 17), hydronephrosis (n = 1), concurrent pleural disease (n = 2), lymph nodes (n = 1) and abdominal wall disease (n = 4) was considered unfavourable. While 78.9% of patients who underwent complete cytoreduction had no disease at unfavourable sites, 75% of those who underwent MTD did have disease at these sites. There was significant difference in the radiological peritoneal cancer index, severity of upper abdominal disease, small bowel and mesenteric involvement between patients who underwent complete cytoreduction and MTD for malignant peritoneal mesothelioma. Complete cytoreduction was not achieved in the presence of a rind of soft tissue around the small bowel (p = 0.016) and was unlikely in the presence of large volume upper abdominal disease (p = 0.06).

CONCLUSION

Involvement of key anatomical sites such as small bowel serosa and large volume upper abdominal disease reduced the likelihood of achieving complete cytoreduction in patients with malignant peritoneal mesothelioma. Advances in knowledge: Demonstration of small bowel disease and large volume upper abdominal disease on imaging in patients with malignant peritoneal mesothelioma can be used to identify patients who may not benefit from cytoreductive surgery.

A Histomorphologic Grading System That Predicts Overall Survival in Diffuse Malignant Peritoneal Mesothelioma With Epithelioid Subtype

Supplemental Digital Content is available in the text.

Diffuse malignant peritoneal mesothelioma (MPeM) is rare and arises from peritoneal serosal surfaces. Although it shares similar histomorphology with its counterpart, malignant pleural mesothelioma, etiologies, clinical courses, and therapies differ. Nuclear grading and level of mitoses have been correlated with prognosis in malignant pleural mesothelioma with epithelioid subtype. Whether nuclear grading and level of mitoses correlate with prognosis in MPeM is still unknown. Our study utilizes a 2 tier system incorporating nuclear features and level of the mitoses to stratify cases of MPeM with epithelioid subtype. Fifty-one cases of MPeM with clinical follow-up underwent retrospective microscopic review. From that subset, 46 cases were of epithelioid subtype, which were then stratified into a low-grade or high-grade tier. Survival times were calculated on the basis of Kaplan-Meier analysis. The low-grade tier had higher overall survival with a median of 11.9 years and 57% at 5 years when compared with the high-grade tier with a median of 3.3 years and 21% at 5 years (P=0.002). Although not statistically significant, the low-grade tier had higher progression-free survival with a median of 4.7 years and 65% at 5 years when compared with the high-grade tier with a median of 1.9 years and 35% at 5 years (P=0.089). Our study is first to specifically evaluate and correlate nuclear features and level of mitoses with overall survival in MPeM with epithelioid subtype.

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.