Malignant mesothelioma

Telomeres and telomerase in mesothelioma: Pathophysiology, biomarkers and emerging therapeutic strategies (Review)

Malignant mesothelioma (MM) is a rare but aggressive cancer linked to asbestos exposure and characterized by advanced‑stage disease at presentation. Despite advances in treatment, prognosis remains abysmal, highlighting the imperative for the development of novel biomarkers and treatment approaches. Telomere biology plays a pivotal role in the tumorigenic process and has emerged as a key area in oncology research. Short telomeres have been associated with genomic instability, and substantially shorter telomere length (TL) has been identified in MM, showcasing the potential of TL in risk assessment, early detection, and disease progression monitoring. MM predominantly maintains TL through telomerase activity (TA), which in research has been identified in >90% of MM cases, underscoring the potential of TA as a biomarker in MM. Telomerase reverse transcriptase (TERT) polymorphisms may serve as valuable biomarkers, with research identifying associations between single nucleotide polymorphisms (SNPs) and the risk and prognosis of MM. Additionally, TERT promoter mutations have been associated with poor prognosis and advanced‑stage disease, with the non‑canonical functions of TERT hypothesized to contribute to the development of MM. TERT promoter mutations occur in ~12% of MM cases; C228T, C250T and A161C are the most common, while the distribution and frequency differ depending on histological subtype. Research reveals the promise of the various approaches therapeutically targeting telomerase, with favorable results in pre‑clinical models and inconclusive findings in clinical trials. The present review examines the role of telomere biology in MM and its implications in diagnosis, prognosis, and therapy.

Long-term survival from multidisciplinary treatment of primary malignant pericardial mesothelioma: A case report

INTRODUCTION AND IMPORTANCE

Primary malignant pericardial mesothelioma is an extremely rare disease with a poor prognosis. Currently, there are no specific guidelines for diagnosis and treatment in Vietnam and international countries for this disease, so treatment experiences from previous clinical cases are very important in the management of this disease.

CASE PRESENTATION

The research team reports a clinical case diagnosed and treated with a combination of surgery and chemotherapy using the Pemetrexed + Carboplatin regimen at the Oncology Center. The patient has survived for an additional 17 months up to the current time.

CLINICAL DISCUSSION

This is an exceptionally rare incident. He survived for a duration of 17 months, which is almost three times longer than the average survival time observed in other documented cases. Additional reports on cases with pericardial mesothelioma are necessary to have a comprehensive understanding of its nature, enabling early identification and appropriate treatment.

CONCLUSION

The patient underwent surgical intervention and received chemotherapy as part of their treatment. The research team emphasizes the importance of a multidisciplinary approach in diagnosing and treating primary malignant pericardial mesothelioma.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Establishment of an experimental model of canine malignant mesothelioma organoid culture using a three-dimensional culture method

Canine malignant mesothelioma (cMM) is a rare and drug-resistant malignant tumor. Due to few patients and experimental models, there have not been enough studies to demonstrate the pathogenesis of the disease and novel effective treatment for cMM. Since cMM resembles human MM (hMM) in histopathological characteristics, it is also considered a promising research model of hMM. Compared with conventional 2-dimensional (2D) culture methods, 3-dimensional (3D) organoid culture can recapitulate the properties of original tumor tissues. However, cMM organoids have never been developed. In the present study, we for the first time generated cMM organoids using the pleural effusion samples. Organoids from individual MM dogs were successfully generated. They exhibited the characteristics of MM and expressed mesothelial cell markers, such as WT-1 and mesothelin. The sensitivity to anti-cancer drugs was different in each strain of cMM organoids. RNA sequencing analysis showed cell adhesion molecule pathways were specifically upregulated in cMM organoids compared with their corresponding 2D cultured cells. Among these genes, the expression level of E-cadherin was drastically higher in the organoids than that in the 2D cells. In conclusion, our established cMM organoids might become a new experimental tool to provide new insights into canine and human MM therapy.

Highlighting the immunohistochemical differences of malignant mesothelioma subtypes via case presentations

Malignant mesothelioma (MM) is a rare tumor of mesothelial cells, with an increasing incidence both in developed and developing countries. MM has three major histological subtypes, in order of frequency, according to the World Health Organization (WHO) Classification of 2021: epithelioid, biphasic, and sarcomatoid MM. Distinction may be a challenging task for the pathologist, due to the unspecific morphology. Here, we present two cases of diffuse MM subtypes to emphasize the immunohistochemical (IHC) differences, and to facilitate diagnostic difficulties. In our first case of epithelioid mesothelioma, the neoplastic cells showed cytokeratin 5/6 (CK5/6), calretinin, and Wilms-tumor-1 (WT1) expression, while remaining negative with thyroid transcription factor-1 (TTF-1). BRCA1 associated protein-1 (BAP1) negativity was seen in the neoplastic cells' nucleus, reflecting loss of the tumor suppressor gene. In the second case of biphasic mesothelioma, expression of epithelial membrane antigen (EMA), CKAE1/AE3, and mesothelin was observed, while WT1, BerEP4, CD141, TTF1, p63, CD31, calretinin, and BAP1 expressions were not detected. Due to the absence of specific histological features, the differentiation between MM subtypes could be a challenging task. In routine diagnostic work, IHC may be the proper method in distinction. According to our results and literature data, CK5/6, mesothelin, calretinin, and Ki-67 should be applied in subclassification.

Malignant Pleural Mesothelioma: Preliminary Toxicity Results of Adjuvant Radiotherapy Hypofractionation in a Prospective Trial (MESO-RT)

Malignant Pleural Mesothelioma (MPM) is a rare malignancy with an overall poor prognosis. The standard therapeutic strategy in early-stage disease is trimodality therapy. In this publication, we report the preliminary toxicity results of the first 20 patients treated with accelerated hypofractionated radiotherapy. Between July 2017 to June 2019, 20 MPM patients were enrolled and treated with accelerated hypofractionated radiotherapy using helical tomotherapy and intensity-modulated arc therapy. The prescription dose was 30 Gy in five daily fractions, while an inhomogeneous dose escalation to 40 Gy was prescribed based solely upon the presence of gross residual tumor. Only one case of G3 toxicity was reported, which was a bilateral pneumonitis that occurred two years after treatment probably due to superinfection. Median Time to Progression reached 18.2 months while one- and three-year Overall Survival rates were 85% (95% CI:60.4-94.9) and 49.5% (95% CI:26.5-68.9), respectively. Treatment of the intact lung with pleural intensity-modulated arc irradiation is a novel treatment strategy that appears to be safe, feasible, and without a high grade of lung toxicity. Survival rates and Time to Progression are encouraging.

Pleural manometry during thoracocentesis in patients with malignant pleural effusion: A randomized controlled trial

Background

Large-volume therapeutic thoracocentesis may be associated with pulmonary congestion or a more serious complication; re-expansion pulmonary edema (RPE). We investigated whether monitoring pleural pressure with manometry during thoracocentesis would prevent these pulmonary symptoms/RPE and allow larger volume drainage.

Methods

We did a randomized controlled trial involving 110 patients with large malignant pleural effusions. Patients were randomly allocated to obtain thoracocentesis with or without pleural manometry. We measured the incidence of pulmonary congestion symptoms, total fluid aspirated, and pleural pressures in both groups. This trial is listed on ClinicalTrials.gov as NCT04420663.

Results

The mean amount of total thoracocentesis fluid withdrawn from the control group was 945.4±78.9 (mL) and 1690.9±681.0 (mL) from the intervention group (P<0.001). Clinical symptoms of pulmonary congestion appeared in (n=20) (36.3%) of patients in the intervention group while no symptoms appeared in controls (P<0.001). The difference between opening and closing pressures between the non-symptomatic cluster and the symptomatic cluster was (32.8±15.6 versus 42.2±13) respectively (P=0.02). Total fluid withdrawn from the non-symptomatic cluster was 1828.5±505 mL in comparison to 1,450±875 mL in the symptomatic cluster (P=0.04).

Conclusion

Pleural manometry can be used to increase the volume of fluid removed on each occasion in patients with malignant pleural effusion. In our study, pleural manometry was associated with a larger number of pulmonary congestion symptoms/RPE. We believe that manometry may be a useful tool to not exceed a 17 cm H2O gradient in pleural pressure which should be avoided to prevent pulmonary congestion symptoms or RPE. Pulmonary congestion symptoms/RPE are not related to the amount of volume withdrawn but to the gradient of pleural pressure drop. Our conclusion does support the adoption of pleural manometry whenever large-volume thoracocentesis is intended.

The Scrotal Excision of Paratesticular Mesothelioma of the Tunica Vaginalis: A Case Report

Mesotheliomas are malignancies which involve mesothelial cells, and are commonly found in the pleura, peritoneum, pericardium, and (rarely) the testis. We present a case of paratesticular mesothelioma that was excised without the testis. An elderly gentleman presented with a painless right scrotal mass, which appeared clinically benign and separable from the underlying testis. An ultrasound showed an extratesticular lesion adhered to the scrotal wall with a complex hydrocele. An excisional biopsy was conducted, and the Jaboulay procedure was performed on the right testis. Pathological examination revealed mesothelioma, showing focal invasion into the underlying stroma. A post-operative computed tomography (CT) scan evaluation manifested no local or distant metastasis. No further surgery was performed, and no chemotherapy or radiotherapy was offered to the patient. Subsequent clinical examinations and radiological scans carried out during each clinic follow-up for two years showed no new lesion or recurrence.

Factors affecting the life expectancy in malignant pleural mesothelioma: Our 10 years of studies and experience

Malignant pleural mesothelioma (MPM) is an aggressive tumor with a poor prognosis. In our study, we aimed to investigate the specific clinical, laboratory, and radiological features of the tumor and the prognostic effect of SUVmax (maximum standardized uptake values) according to PET/CT (positron emission tomography). Demographic, therapeutic, clinical, and survival information of patients diagnosed with histologically-validated pleural mesothelioma in our hospital between January 2010 to December 2019 will be retrospectively scanned from the hospital records. A total of 116 patients, 61 men (52.6%), and 55 women (47.4%), were analyzed. Thirty five patients (30.2%) were over the age of 65. Percentage of patients over 65 years of age, neutrophil count, and PET SUV Max values, asbestos exposure and pleural thickening rate were significantly higher in the deceased patients' group than in the living patients' group (P = .042, P = .039, P = .002, P = .004, P = .037). T stage (tumor stage), N stage (lymph nodes stage), metastasis stage, and Grade distribution were significantly higher in the deceased patients' group than in the living patients' group (P < .000, P < .000, P = .003, P < .000). The rates of chemotherapy and surgical treatment, right lung location, and epithelioid pathology were significantly lower in the deceased patients' group compared to the living patients' group (P = .016, P = .030, P = .018, P = .008). The mean follow-up time was 13 months. Key determinants of survival in MPM include age, male gender, neutrophil increase, pleural thickening, high PET SUV max values, stage, histological type, asbestos exposure, and treatment regimen.

The impact of COVID-19 on new mesothelioma diagnoses in Italy

Background

The aim of this work was to evaluate the impact of the restrictions put in place to control the COVID‐19 pandemic on new diagnoses of malignant mesothelioma (MM) in Italy.

Methods

Twelve of the 21 Italian malignant mesothelioma CORs (regional operating centres) participated. The study included all cases of MM with microscopic confirmation; cases without microscopic confirmation and death certificate only (DCO) were excluded. For each case, information on sex, date of birth, tumor site, morphology, and date of diagnosis was retrieved. We compared the number of incident cases in 2020 with 2019, looking at the overall picture and for four periods: pre‐pandemic (January–February), first wave (March–May), low incidence (June–September), and second wave (October–December).

Results

A total of 604 cases were registered: 307 in 2019 and 297 in 2020. In the 2020 pre‐pandemic period, the incidence was higher than in the same months in 2019 (+45%); there was no significant change during the first wave (+1%) or in the low‐incidence period (−3%), while a decrease was observed during the second wave (−32%). However, the data were not homogeneous across the country: the increase in the pre‐pandemic period concerned mostly the regions of northern (+61.5%) and central Italy (+43.5%); during the first wave, MM diagnoses increased in the northern (+38.5%) and central (+11.4%) regions but decreased in the southern regions (−52.9%). All these differences are compatible with random fluctuations.

Conclusion

The COVID‐19 pandemic had little or no impact on new MM diagnoses, and variations were not homogeneous throughout the country.

Survival of Korean Patients with Malignant Pleural Mesothelioma Compensated for the Asbestos Injury Relief

Background: The purpose of this study was to identify the epidemiologic characteristics and prognostic factors for malignant pleural mesothelioma in Korea, which are currently insufficient. The data were derived from malignant mesothelioma patients who registered under the Asbestos Injury Relief Act; Methods: A total of 728 patients received compensation from the Asbestos Injury Relief Act due to malignant mesothelioma between 2011 and 2015. Of these, 313 patients (43.0%) with malignant pleural mesothelioma were included in the study. The study variables were sex (male, female), age at diagnosis (<59, 60–69, ≥70), smoking history (yes, no), surgery (yes, no), chemotherapy (yes, no), occupational exposure to asbestos (yes, no), and histological subtype (epithelioid, nonepithelioid); Results: Median survival of mesothelioma was 8.0 months (95% confidence interval: 6.2 to 9.8). The 1-year, 2-year, and 5-year survival rates (%) were 43.5%, 23.6%, and 12.5%, respectively. In multivariate analysis of Cox’s proportional hazards model; sex, age, smoking history, occupational asbestos exposure, and histological subtype were not significant prognostic factors, but surgery and chemotherapy combined was a significant predictor; Conclusions: Although the representativeness of these data is limited, our study estimates the epidemiologic characteristics of malignant pleural mesothelioma. Non-occupational exposure had a similar prognosis to occupational asbestos exposure, and there was no sex difference. In addition, it was found that receiving a combination of surgery and chemotherapy affects the survival rate, but there is a limitation in that factors such as performance status, comorbidities, and stage that contribute to survival are not considered.

Repeated porphyrin lipoprotein-based photodynamic therapy controls distant disease in mouse mesothelioma via the abscopal effect

While photodynamic therapy (PDT) can induce acute inflammation in the irradiated tumor site, a sustained systemic, adaptive immune response is desirable, as it may control the growth of nonirradiated distant disease. Previously, we developed porphyrin lipoprotein (PLP), a ∼20 nm nanoparticle photosensitizer, and observed that it not only efficiently eradicated irradiated primary VX2 buccal carcinomas in rabbits, but also induced regression of nonirradiated metastases in a draining lymph node. We hypothesized that PLP-mediated PDT can induce an abscopal effect and we sought to investigate the immune mechanism underlying such a response in a highly aggressive, dual subcutaneous AE17-OVA+ mesothelioma model in C57BL/6 mice. Four cycles of PLP-mediated PDT was sufficient to delay the growth of a distal, nonirradiated tumor four-fold relative to controls. Serum cytokine analysis revealed high interleukin-6 levels, showing a 30-fold increase relative to phosphate-buffered solution (PBS) treated mice. Flow cytometry revealed an increase in CD4+ T cells and effector memory CD8+ T cells in non-irradiated tumors. Notably, PDT in combination with PD-1 antibody therapy prolonged survival compared to monotherapy and PBS. PLP-mediated PDT shows promise in generating a systemic immune response that can complement other treatments, improving prognoses for patients with metastatic cancers.

Monocytic Ontogeny of Regenerated Macrophages Characterizes the Mesotheliomagenic Responses to Carbon Nanotubes

Macrophages are not only derived from circulating blood monocytes or embryonic precursors but also expand by proliferation. The origin determines macrophage fate and functions in steady state and pathological conditions. Macrophages predominantly infiltrate fibre-induced mesothelioma tumors and contribute to cancer development. Here, we revealed their ontogeny by comparing the response to needle-like mesotheliomagenic carbon nanotubes (CNT-7) with tangled-like non-mesotheliomagenic CNT-T. In a rat peritoneal cavity model of mesothelioma, both CNT induced a rapid macrophage disappearance reaction (MDR) of MHCII^low resident macrophages generating an empty niche available for macrophage repopulation. Macrophage depletion after mesotheliomagenic CNT-7 was followed by a substantial inflammatory reaction, and macrophage replenishment completed after 7 days. Thirty days after non-mesotheliomagenic CNT-T, macrophage repopulation was still incomplete and accompanied by a limited inflammatory reaction. Cell depletion experiments, flow cytometry and RNA-seq analysis demonstrated that, after mesotheliomagenic CNT-7 exposure, resident macrophages were mainly replaced by an influx of monocytes, which differentiated locally into MHCII^high inflammatory macrophages. In contrast, the low inflammatory response induced by CNT-T was associated by the accumulation of self-renewing MHCII^low macrophages that initially derive from monocytes. In conclusion, the mesotheliomagenic response to CNT specifically relies on macrophage niche recolonization by monocyte-derived inflammatory macrophages. In contrast, the apparent homeostasis after non-mesotheliomagenic CNT treatment involves a macrophage regeneration by proliferation. Macrophage depletion and repopulation are thus decisive events characterizing the carcinogenic activity of particles and fibres.

Impact of Previous Gynecologic Surgical Procedures on Outcomes of Non-Gynecologic Peritoneal Malignancies Mimicking Ovarian Cancer: Less Is More?

BACKGROUND

Non-gynecologic rare peritoneal surface malignancies (PSMs) often are misdiagnosed as disseminated ovarian cancer and initially treated by gynecologic surgeons. This study aimed to assess whether these previous maneuvers (i.e., full surgical staging and/or cytoreductive attempts) affect outcomes after the definitive surgery performed in a tertiary center.

METHODS

The study reviewed 298 women affected by non-gynecologic PSM who underwent cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) after previous gynecologic surgery. Prior surgery was categorized as limited surgery (pLS: abdominal exploration with biopsy plus adnexectomy and/or appendectomy) or extended surgery (pES: full surgical staging or cytoreductive attempts including hysterectomy with bilateral salpingo-oophorectomy).

RESULTS

Of the 298 patients, 143 had pLS and 153 had pES. Morbidity was similar between the groups (P = 0.143), but the pES group had more severe urinary tract injuries (19 vs. 3; P < 0.001), longer operating time (585.9 vs. 506.7; P = 0.027), and more patients needing more than two anastomoses (41 vs. 26; P = 0.033). Age older than 55 years (odds ratio [OR] 2.42; P = 0.009) and number of anastomoses (OR 3.17; P = 0.002) correlated with severe morbidity; pES correlated with urinary tract grades 3 and 4 injuries (OR 7.9; P = 0.001). The 5-year cumulative incidence of locoregional relapse was significantly higher in the pES group (0.41 vs. 0.27; P = 0.012; median follow-up period, 69 months). The multivariate analysis identified a Peritoneal Carcinomatosis Index (PCI) higher than 20 and pES as independent risk factors.

CONCLUSION

For women undergoing CRS±HIPEC for non-gynecologic PSM, the risk for locoregional relapse and severe postsurgical urinary tract complications is increased by pES. Therefore, prior full surgical staging or cytoreductive attempts without definitive gynecologic histology should be avoided. Prophylactic ureteral stenting and stricter oncologic follow-up assessment must be considered in this scenario.

Ascertainment Bias in a Historic Cohort Study of Residents in an Asbestos Manufacturing Community

This paper describes follow-up for a cohort of 4530 residents living in the asbestos manufacturing community of Ambler, PA, U.S. in 1930. Using re-identified census data, cause and date of death data obtained from the genealogic website Ancestry.com, along with geospatial analysis, we explored relationships among demographic characteristics, occupational, paraoccupational and environmental asbestos exposures. We identified death data for 2430/4530 individuals. Exposure differed significantly according to race, gender, age, and recency of immigration to the U.S. Notably, there was a significant difference in the availability of year of death information for non-white vs. white individuals (odds ratio (OR) = 0.62 p-value < 0.001), females (OR = 0.53, p-value < 0.001), first-generation immigrants (OR = 0.67, p-value = 0.001), second-generation immigrants (OR = 0.31, p-value < 0.001) vs. non-immigrants, individuals aged less than 20 (OR = 0.31 p-value < 0.001) and individuals aged 20 to 59 (OR = 0.63, p-value < 0.001) vs. older individuals. Similarly, the cause of death was less often available for non-white individuals (OR = 0.42, p-value <0.001), first-generation immigrants and (OR = 0.71, p-value = 0.009), second-generation immigrants (OR = 0.49, p-value < 0.001), individuals aged less than 20 (OR = 0.028 p-value < 0.001), and individuals aged 20 to 59 (OR = 0.26, p-value < 0.001). These results identified ascertainment bias that is important to consider in analyses that investigate occupational, para-occupational and environmental asbestos exposure as risk factors for mortality in this historic cohort. While this study attempts to describe methods for assessing itemized asbestos exposure profiles for a community in 1930 using Ancestry.com and other publicly accessible databases, it also highlights how historic cohort studies likely underestimate the impact of asbestos exposure on vulnerable populations. Future work will aim to assess mortality patterns in this cohort.

Asbestos in High-Risk Communities: Public Health Implications

Asbestos-related diseases (ARDs)-mesothelioma, lung cancer, and asbestosis-are well known as occupational diseases. As industrial asbestos use is eliminated, ARDs within the general community from para-occupational, environmental, and natural exposures are more prominent. ARD clusters have been studied in communities including Broni, Italy; Libby, Montana; Wittenoom, Western Australia; Karain, Turkey; Ambler, Pennsylvania; and elsewhere. Community ARDs pose specific public health issues and challenges. Community exposure results in higher proportions of mesothelioma in women and a younger age distribution than occupational exposures. Exposure amount, age at exposure, fiber type, and genetic predisposition influence ARD expression; vulnerable groups include those with social and behavioral risk, exposure to extreme events, and genetic predispositions. To address community exposure, regulations should address all carcinogenic elongated mineral fibers. Banning asbestos mining, use, and importation will not reduce risks from asbestos already in place. Residents of high-risk communities are characteristically exposed through several pathways differing among communities. Administrative responsibility for controlling environmental exposures is more diffuse than for workplaces, complicated by diverse community attitudes to risk and prevention and legal complexity. The National Mesothelioma Registries help track the identification of communities at risk. High-risk communities need enhanced services for screening, diagnosis, treatment, and social and psychological support, including for retired asbestos workers. Legal settlements could help fund community programs. A focus on prevention, public health programs, particularization to specific community needs, and participation is recommended.

Prognosis of patients with malignant mesothelioma by expression of programmed cell death 1 ligand 1 and mesothelin in a contemporary cohort in Finland

OBJECTIVES

We aimed to describe mesothelin (MSLN) and programmed cell death 1 ligand 1 (PD-L1) tumour overexpression amongst patients with malignant mesothelioma (MM), and their associations with survival, amongst a cohort of patients with MM in Finland.

METHODS

Between 2004 and 2017, 91 adults with histologically confirmed MM were identified from the Auria Biobank in Finland and followed-up using linked data from electronic health records and national statistics. Biomarker content in tumour cell membranes was determined using automated Immunohistochemistry on histological sections. Stained tumour sections were scored for MSLN and PD-L1 intensity. Adjusted associations between MSLN/PD-L1 co-expression and mortality were evaluated by estimating hazard ratios (HRs) with 95% confidence intervals (CIs) using Cox regression.

RESULTS

Biomarker overexpression occurred in 52 patients for MSLN and 34 patients for PD-L1 and was associated with tumour histology and certain comorbidities. Fifteen per cent of patients had a tumour that overexpressed both biomarkers; r =-0.244, p-value: 0.02. Compared with MSLN+/PD-L1+ patients, HRs (95% CIs) for death were 4.18 (1.71-10.23) for MSLN-/PD-L1+ patients, 3.03 (1.35-6.77) for MSLN-/PD-L1- patients, and 2.13 (0.97-4.67) for MSLN+/PD-L1- patients.

CONCLUSIONS

Both MSLN and PD-L1 markers were independent prognostic indicators in patients with MM. Overexpression of MSLN was associated with longer survival; yet their combined expression gave a better indication of survival. The risk of death was four times higher amongst MSLN-/PD-L1+ patients than in MSLN+/PD-L1+ patients.

Extracellular Vesicles-Based Drug Delivery Systems: A New Challenge and the Exemplum of Malignant Pleural Mesothelioma

Research for the most selective drug delivery to tumors represents a fascinating key target in science. Alongside the artificial delivery systems identified in the last decades (e.g., liposomes), a family of natural extracellular vesicles (EVs) has gained increasing focus for their potential use in delivering anticancer compounds. EVs are released by all cell types to mediate cell-to-cell communication both at the paracrine and the systemic levels, suggesting a role for them as an ideal nano-delivery system. Malignant pleural mesothelioma (MPM) stands out among currently untreatable tumors, also due to the difficulties in achieving an early diagnosis. Thus, early diagnosis and treatment of MPM are both unmet clinical needs. This review looks at indirect and direct evidence that EVs may represent both a new tool for allowing an early diagnosis of MPM and a potential new delivery system for more efficient therapeutic strategies. Since MPM is a relatively rare malignant tumor and preclinical MPM models developed to date are very few and not reliable, this review will report data obtained in other tumor types, suggesting the potential use of EVs in mesothelioma patients as well.

Multicystic and diffuse malignant peritoneal mesothelioma in children

BACKGROUND

Malignant and multicystic peritoneal mesotheliomas are extremely rare tumors in children, developing from mesothelial cells. No specific guidelines are available at this age.

METHODS

We performed a retrospective analysis of all identified children (< 18-year-old) treated in France from 1987 to 2017 for a diffuse malignant peritoneal mesothelioma (DMPM) or a multicystic peritoneal mesothelioma (MCPM).

RESULTS

Fourteen patients (5 males and nine females), aged 2.2 to 17.5 years, were included. The most frequent presenting symptoms were abdominal pain, ascitis, and alteration in the general condition. Eight patients had epithelioid mesothelioma, three had biphasic mesothelioma, and three had MCPM. Eight patients with DMPM diagnosis received cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Among them, six patients had neoadjuvant systemic chemotherapy, one patient, post-operative chemotherapy, and one patient CRS and HIPEC only. Three patients received only systemic chemotherapy. All patients with MCPM had only surgery. After a median follow-up of seven years (2-15), six patients (6/11; one death) with DMPM and two patients (two/three) with MCPM had a local and distant recurrences.

CONCLUSION

Peritoneal mesothelioma in children is a rare condition with difficult diagnosis and high risk of recurrence. Worldwide interdisciplinary collaboration and networking are mandatory to help diagnosis and provide harmonious treatment guidelines.

Localized biphasic malignant mesothelioma presenting as a giant pelvic wall mass: a rare case report and literature review

Background

Localized biphasic MPeM is rare in clinical practice, we reviewed 8 cases of localized biphasic MPeM (including our present case), and summarized the clinical and imaging features of the disease.

Case presentation

We reported a 79-year-old man with chief complaint of a narrowing in the caliber of the stool for one year. A soft tissue shadow was occasionally found by CT examination in the right pelvic wall, and it was diagnosed as localized biphasic malignant peritoneal mesothelioma (MPeM) by postoperative pathology. Radical excision was performed and no radio-chemotherapy was applied. Nearly six years after surgery, the mass was significantly enlarged, and the neighboring tissues including rectum, prostate, seminal vesicle, and right ischial ramus were all infiltrated. The patient was in the end stage of cancer with poor prognosis.

Conclusions

The localized biphasic MPeM may show following characteristics: (1) with heterogeneous low-density and obscure margin; (2) with low incidence rate of ascites; (3) with few central hemorrhage and necrosis; (4) with few calcified structures; (5) with mild to moderate heterogeneous delayed enhancement on contrast-enhanced CT. The imaging characteristics can provide further information for the diagnosis of localized biphasic MPeM in the future.

In-vitro proliferation assay with recycled ascitic cancer cells in malignant pleural mesothelioma: A case report

BACKGROUND

We report the first case, to the best of our knowledge, of massive ascites due to recurrent malignant pleural mesothelioma that was controlled using KM-cell-free and concentrated ascites reinfusion therapy (KM-CART). The tumor cells derived via KM-CART were utilized secondarily in an in vitro cell growth assay using the collagen gel droplet-embedded culture drug sensitivity test (CD-DST) to investigate anticancer drug susceptibility.

CASE SUMMARY

A 56-year-old man presented with recurrent malignant mesothelioma with massive ascites; more than 4000 mL of ascitic fluid was removed, filtered, and concentrated using KM-CART, and the cell-free ascitic fluid was reinfused into the patient to improve quality of life. Cancer cells isolated secondarily in an in vitro proliferation assay using CD-DST exhibited low sensitivity to pemetrexed and high sensitivity to gemcitabine. Treatment with gemcitabine maintained stable disease for 4 mo.

CONCLUSION

The combination of KM-CART and CD-DST may be a promising treatment option for malignant ascites associated with malignant mesothelioma.

Potential Airborne Asbestos Exposure and Risk Associated with the Historical Use of Cosmetic Talcum Powder Products

Over time, concerns have been raised regarding the potential for human exposure and risk from asbestos in cosmetic-talc-containing consumer products. In 1985, the U.S. Food and Drug Administration (FDA) conducted a risk assessment evaluating the potential inhalation asbestos exposure associated with the cosmetic talc consumer use scenario of powdering an infant during diapering, and found that risks were below levels associated with background asbestos exposures and risk. However, given the scope and age of the FDA's assessment, it was unknown whether the agency's conclusions remained relevant to current risk assessment practices, talc application scenarios, and exposure data. This analysis updates the previous FDA assessment by incorporating the current published exposure literature associated with consumer use of talcum powder and using the current U.S. Environmental Protection Agency's (EPA) nonoccupational asbestos risk assessment approach to estimate potential cumulative asbestos exposure and risk for four use scenarios: (1) infant exposure during diapering; (2) adult exposure from infant diapering; (3) adult exposure from face powdering; and (4) adult exposure from body powdering. The estimated range of cumulative asbestos exposure potential for all scenarios (assuming an asbestos content of 0.1%) ranged from 0.0000021 to 0.0096 f/cc-yr and resulted in risk estimates that were within or below EPA's acceptable target risk levels. Consistent with the original FDA findings, exposure and corresponding health risk in this range were orders of magnitude below upper-bound estimates of cumulative asbestos exposure and risk at ambient levels, which have not been associated with increased incidence of asbestos-related disease.

Radiation Therapy for Treatment of Adolescent and Young Adult Hodgkin Lymphoma and Risk for Cardiovascular Disease and Cancer

PURPOSE

To estimate the risk for hospitalizations among survivors of Hodgkin lymphoma diagnosed in adolescence or young adulthood according to exposure to treatment with radiation therapy.

METHODS

Through the files of the Danish Cancer Registry, we identified 1684 five-year survivors of Hodgkin lymphoma, diagnosed at age 15-39 years during the period 1943-2004, and for whom information on radiation therapy was available in the Cancer Registry. Population-based comparisons were identified through the Danish Civil Registration System and matched to the survivors on year of birth and sex. Survivors of Hodgkin lymphoma and comparisons were linked to the Danish National Patient Register for information on hospitalizations. Standardized hospitalization rate ratios (RR) and absolute excess rates (AERs) were estimated for total number of hospitalizations and for hospitalizations for cardiovascular disease, cancer and several other disease groups.

RESULTS

Overall, survivors of Hodgkin lymphoma who received radiation therapy had higher risk (RR 2.0) and AER (AER 588) of hospitalization than survivors not treated with radiation therapy (RR 1.8; AER 399). Especially, the risk for cardiovascular disease and cancer was high among survivors who received radiation therapy (RR 2.8 and 3.6) compared with survivors who did not receive this type of treatment (RR 2.2 and 2.3).

CONCLUSION

Survivors of adolescent and young adult Hodgkin lymphoma treated with radiation therapy had a higher risk of diseases requiring hospitalization than survivors not treated with radiation therapy. Irrespective of the type of treatment received, initiatives that prevent and minimize hospital-requiring late effects in survivors of Hodgkin lymphoma are needed.

Aquaporin-1 expression in fluoro-edenite-induced mesothelioma effusions: An approach by cell-block procedure

OBJECTIVE

Aquaporin 1 (AQP-1) is a water channel protein found in cell membranes, whose expression has been considered an independent favourable prognostic factor in pleural malignant mesothelioma (MM). The aim of this study was to evaluate the expression of AQP-1 and its prognostic value in a series of pleural MM effusions, from a geographical area with high concentrations of fluoro-edenite (FE).

METHODS

We selected 25 MM cases from Biancavilla (Italy), an area with high environmental concentrations of FE. Cytological samples, cell-blocks (CB), clinical and follow-up data were available for all cases. Immunohistochemistry for calretinin, CK5/6, WT1, CK7 and TTF1 was used on CB sections to confirm the cytological diagnosis of MM. Immunohistochemistry for AQP-1 was performed and high expression was defined when ≥50% of tumour cells showed linear and circumferential membranous staining.

RESULTS

The cohort included 16 men and nine women (median age: 67.5 years; range: 49-88 years). The median survival was 14 months (range 1.5-60 months), with a significant value (P = 0.006). All cases have been histologically confirmed and classified as epithelioid (16 cases), biphasic (seven cases) and sarcomatoid (two cases). AQP-1 high expression has been observed in 16 cases. Comparing AQP-1 high expression to the survival of corresponding patients, a significant association with a slight increased overall survival of 12 months has been demonstrated. Nine patients with a AQP-1 score less than 50% showed a shorter median overall survival (7 months).

CONCLUSIONS

AQP-1 high expression is detectable on cytological samples of FE-induced MM with a prognostic value.

Variations in mesothelioma mortality rates among migrants to Australia and Australian-born

BACKGROUND

Australia's use and consumption of asbestos occurred at the same time as its immigration boom. Our objective was to investigate mesothelioma death rates among migrants and Australian-born between 1981 and 2012.

METHODS

Australian national mesothelioma deaths from 1981 to 2002 and 2006 to 2012 together with national censuses from 1981 to 2011 were extracted and combined. Directly standardised rates and negative binomial regression were applied examining differences in mesothelioma death rates with regard to country of birth.

RESULTS

Migrants from the UK and Ireland, Italy and Germany had significantly higher mesothelioma death rates than Australian-born; lower rates were observed among migrants from other countries.

CONCLUSIONS

Our findings suggest there may have been differences in occupational health and safety between foreign and Australian-born. Because of changes in the demographics of migrants to Australia since the 1970s and changes in occupational circumstances over time, further comparisons of occupational-related health outcomes between foreign and Australian-born could identify potential occupational inequalities that may still exist today.

Antitumor-specific T-cell responses induced by oncolytic adenovirus ONCOS-102 (AdV5/3-D24-GM-CSF) in peritoneal mesothelioma mouse model

Oncolytic adenoviral immunotherapy activates the innate immune system with subsequent induction of adaptive tumor‐specific immune responses to fight cancer. Hence, oncolytic viruses do not only eradicate cancer cells by direct lysis, but also generate antitumor immune response, allowing for long‐lasting cancer control and tumor reduction. Their therapeutic effect can be further enhanced by arming the oncolytic adenovirus with costimulatory transgenes and/or coadministration with other antitumor therapies. ONCOS‐102 has already been found to be well tolerated and efficacious against some types of treatment‐refractory tumors, including mesothelin‐positive ovarian cancer (NCT01598129). It induced local and systemic CD8+ T‐cell immunity and upregulated programmed death ligand 1. These results strongly advocate the use of ONCOS‐102 in combination with other therapeutic strategies in advanced and refractory tumors, especially those expressing the mesothelin antigen. The in vivo work presented herein describes the ability of the oncolytic adenovirus ONCOS‐102 to induce mesothelin‐specific T‐cells after the administration of the virus in bagg albino (BALB/c) mice with mesothelin‐positive tumors. We also demonstrate the effectiveness of the interferon‐γ the enzyme‐linked immunospot (ELISPOT) assay to detect the induction of T‐cells recognizing mesothelin, hexon, and E1A antigens in ONCOS‐102‐treated mesothelioma‐bearing BALB/c mice. Thus, the ELISPOT assay could be useful to monitor the progress of therapy with ONCOS‐102.

Primary Spinal Malignant Mesothelioma: A Case Report and Literature Review

BACKGROUND

Malignant mesotheliomas are aggressive and rapidly fatal neoplasms arising from the mesothelial cells. The most common sites of origin are the pleural and peritoneal cavities; the pericardium and the tunica vaginalis are infrequently involved, and malignant mesothelioma in the spinal canal is extremely rare. Here we report a case of primary spinal malignant mesothelioma. We also report the results of a literature search conducted in PubMed with specific key terms, inclusion criteria, and exclusion criteria, with a comparison of elected case studies and case series, and statistical analysis as appropriate.

CASE DESCRIPTION

A 35-year-old man presented with a 3-month history of swelling and pain in the left lower extremity. Neurologic examination revealed a loss of sensation below the L5 dermatome. Magnetic resonance imaging (MRI) showed a mass at the L4-5 level. A diagnosis of schwannoma was suspected, and surgical resection was performed. Histopathological findings were consistent with sarcomatoid malignant mesothelioma. Thoracic and whole-abdomen computed tomography yielded normal results. The patient refused adjuvant radiotherapy or chemotherapy. Positron emission tomography-computed tomography performed at 3 months postoperatively showed no abnormality. At 8 months postoperatively, the patient developed back pain and difficulty with defecation; MRI demonstrated tumor recurrence. During a second operation, invasion of the vertebra and cauda equina was noted. A subtotal resection was achieved, and the pain was partially alleviated. Two months later, the patient succumbed to a traffic accident.

CONCLUSIONS

Spinal malignant mesothelioma is an extremely rare but highly aggressive entity. Preoperative identification is challenging, and definitive diagnosis depends on histopathological evidence. Surgical resection can help relieve the symptoms, but the overall prognosis is poor.

Quality of life of survivors of malignant pleural mesothelioma in Japan: a cross sectional study

BACKGROUND

Previous studies have indicated that people with malignant pleural mesothelioma (MPM) have a poor quality of life (QOL); however, information about the QOL of people with MPM in Japan is anecdotal. The aims of this study were to investigate the QOL of survivors of MPM in Japan and to determine the factors that correlate with their QOL.

METHODS

This was a cross sectional study. The included patients were those diagnosed with MPM in Japan. We created a self-administered questionnaire consisting of 64 questions. The questionnaires were sent to hospitals and patient advocacy groups, distributed to the patients, completed, and sent back to the researchers by postal mail. QOL was assessed with the European Organization for Research and Treatment of Cancer 16 questionnaire (QLQ) and the short version of the core domains of the Comprehensive Quality of Life Outcome questionnaire (CoQoLo).

RESULTS

In total, 133 questionnaires were collected. The QLQ assessments demonstrated that the survivors of MPM most frequently complained of fatigue, pain, sleep disturbances, and dyspnea. The symptom scales were acceptable, but the functional scales were significantly poorer for the patients with poor performance statuses (PSs). The short CoQoLo assessment was very unfavorable for 'Being free from physical pain.' Being a long-term survivor and a survivor with a poor PS were significantly correlated with poor global health status.

CONCLUSIONS

Survivors of MPM have impaired function, a variety of symptoms, and lower QOL. Survivors of MPM, even those in good physical condition, need broad support.

Content validity and ePRO usability of the BPI-sf and "worst pain" item with pleural and peritoneal mesothelioma

Background

The Brief Pain Inventory-short form (BPI-sf) is widely used in self-reported pain assessment, incorporates pain numeric rating scales (NRS) and is commonly utilized in electronic format in clinical trials, however, there is no published information about its usability as an electronic patient-reported outcome (ePRO) measure. The objective of this qualitative study was threefold: 1) to better understand pain experiences among patients with pleural or peritoneal mesothelioma; 2) to assess the interpretability of the instructions, item stem, recall period, and response option of the "worst pain" item of the BPI-sf; and 3) to examine the usability of the TrialMax Touch™ (CRF Health, Inc., Plymouth Meeting, PA) screen-based handheld device and the electronic format of the BPI-sf in a sub-sample of pleural mesothelioma patients.

Methods

A cross-sectional qualitative study was conducted among participants with pleural and peritoneal mesothelioma recruited from 4 clinical sites in the US. Semi-structured telephone or in-person interviews were conducted consisting of concept elicitation, cognitive interviewing of the 11-item BPI-sf, and in-person interview evaluation of ePRO assessment usability in pleural mesothelioma patients.

Results

Twenty-one participants recruited from 4 clinical sites in the US were interviewed in-person (n = 9) and by telephone (n = 12); 71% male; mean age 68.7 ± 13.6 years. Pleural and peritoneal patients described pain as ranging from discomfort to intense pain and reported being able to distinguish tumor pain from treatment pain. The BPI-sf "worst pain" item was relevant to, and easily understood by, study participants with pleural and peritoneal mesothelioma. The ePRO version was found to be easy to use, but readability of small font may be an issue. Participants reported minimal differences between their responses on the paper and ePRO version for all of the pain severity and pain interference items.

Conclusions

Results support the relevance and ease of understanding of the "worst pain" item and provide support for its content validity in patients with pleural and peritoneal mesothelioma. Usability of the ePRO format of the BPI-sf was confirmed for use in clinical trials among patients with pleural mesothelioma.

Ambient Asbestos Fiber Concentrations and Long-Term Trends in Pleural Mesothelioma Incidence between Urban and Rural Areas in the United States (1973-2012)

Over the past 40 years, measured ambient asbestos concentrations in the United States have been higher in urban versus rural areas. The purpose of this study was to determine whether variations in ambient asbestos concentrations have influenced pleural mesothelioma risk in females (who generally lacked historic occupational asbestos exposure relative to males). Male pleural mesothelioma incidence trends were analyzed to provide perspective for female trends. Annual age-adjusted incidence rates from 1973 to 2012 were obtained from the SEER 9, 13, and 18 databases for urban and rural locations, and standardized rate ratios were calculated. Female rural rates exceeded urban rates in almost half of the years analyzed, although the increases were not statistically significant, which is in line with expectations if there was no observable increased risk for urban locations. In contrast, male urban rates were elevated over rural rates for nearly all years examined and were statistically significantly elevated for 22 of the 40 years. Trend analyses demonstrated that trends for females remained relatively constant over time, whereas male urban and rural incidence increased into the 1980s and 1990s, followed by a decrease/leveling off. Annual female urban and rural incidence rates remained approximately five- to six-fold lower than male urban and rural incidence rates on average, consistent with the comparatively increased historical occupational asbestos exposure for males. The results suggest that differences in ambient asbestos concentrations, which have been reported to be 10-fold or greater across regions in the United States, have not influenced the risk of pleural mesothelioma.

Expression analysis of HMGB1 in histological samples of malignant pleural mesothelioma

AIMS

High mobility group box 1 (HMGB1) is a chromatin structural protein, expressed ubiquitously in the nuclei of mammalian cells. When transported extracellularly, it acts as a tumour suppressor and oncogenic protein. In malignant pleural mesothelioma (MPM), high serum levels of HMGB1 have been related to a poor prognosis. Conversely, the significance of HMGB1 expression in MPM tissues is still unclear.

METHODS AND RESULTS

Biopsy samples from 170 patients with MPM were assessed by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) to evaluate HMGB1 protein and gene expression. The expression level of HMGB1 protein was scored using a semiquantitative system that sums the intensity (0-3) and the percentage (from 0 to 4) of positively stained cells in nuclei, cytoplasm and in both. The final score was considered as high (>3) or low (<3) expression. Gene expression levels were calculated using the ΔΔC_t method. High expression levels of HMGB1 as total (P = 0.0011) and cytoplasmic score (P = 0.0462) were related to a worse disease-specific survival (DSS) in the entire cohort and in the clinicopathological subgroups. No significant correlation was found between HMGB1 gene expression and DSS.

CONCLUSIONS

These findings indicate that HMGB1 may be a useful prognostic biomarker in MPM when detected by immunohistochemistry. Conversely, as it is also expressed in normal and reactive mesothelial cells, HMGB1 cannot be considered a diagnostic biomarker in histological samples of mesothelioma.

No Implication of Simian virus 40 in pathogenesis of Malignant Pleural Mesothelioma in Slovenia

Background and aim

Malignant mesothelioma is predominantly caused by asbestos exposure, although the association of Simian virus 40 in its pathogenesis is currently still under debate. Simian virus 40, a DNA rhesus monkey virus with oncogenic properties, accidentally contaminated early batches of polio vaccine in the 1960s. In the 1990s, viral sequences and proteins were discovered in several human tumors, which triggered research to find a link between Simian virus 40 and human cancers, especially malignant mesothelioma. The aim of our study was to establish an effective laboratory procedure for Simian virus 40 detection and to investigate the presence of Simian virus 40 DNA and small t antigen in mesothelioma samples from Slovenian patients.

Methods and study design

Paraffin-embedded malignant pleural mesothelioma specimens from 103 Slovenian patients were collected and used for total DNA isolation and real-time polymerase chain reaction for Simian virus 40 small t and large T DNA analysis. Special attention was devoted to primer design, good laboratory practice and polymerase chain reaction contamination prevention. Polymerase chain reaction products were sequenced and BLAST aligned. One 5 μm thick paraffin section from each patient's tissue block was stained with hematoxylin and eosin for histological typing and one for immunohistochemical detection of Simian virus 40 small t antigen using a monoclonal antibody against Simian virus 40 (Pab280). SV40-expressing Wi-38 cells were used as positive control in both PCR and immunohistochemistry.

Results

In real-time polymerase chain reaction analyses, only 4 samples gave products with primer pairs amplifying small t antigen and were inconsistent and poorly reproducible. BLAST alignment showed no homology with any deposited SV40 sequences. No immunopositive staining for SV40 small t antigen was found in any of the samples.

Conclusions

We found no evidence of SV40 presence in tissue samples from 103 Slovenian patients with malignant pleural mesothelioma. Asbestos exposure remains the main risk factor for malignant pleural mesothelioma in Slovenia. Free full text available at www.tumorionline.it

An Overview of Asbestos and Malignant Pleural Mesothelioma: An Iranian Perspective

Asbestos refers to a group of minerals that appears naturally in the environment as bundles of fibers. The incidence rate of asbestos-related diseases has considerably increased as well as the amount of asbestos utilization in few countries. Malignant pleural mesothelioma (MPM) is a rare type of aggressive and life threatening neoplasm which arise from various serous surfaces: pleura, peritoneum, tunica vaginalis and pericardium. The first case of MPM was reported in 1947. MPM etiologically is associated to the exposure of asbestos fibers. This form of malignancy is difficult to diagnose in paraclinical work-ups because mesothelioma could occur within 10-20 years of the first-time exposure to asbestos. The burden of MPM is not yet to be wholly understood. The toxic side effects of asbestos on environment and people compelled the European countries to accept the French view upon this matter. However, this approach has not been accepted by some developing countries. This review provides a brief points and facts in relation to MPM and asbestos in Iran.

Malignant pleural mesothelioma - Pleural cavity irradiation after decortication with helical tomotherapy

BACKGROUND

Malignant pleural mesothelioma (MPM) is a rare and aggressive disease that poses a treatment challenge in spite of recent technical developments. The aim of this retrospective analysis is to assess the feasibility of administering intensity-modulated radiotherapy (IMRT) to the pleural cavity using helical tomotherapy in patients who had undergone pleurectomy/decortication (P/D) and also the resulting toxicity levels.

PATIENTS AND METHODS

Ten patients who had MPM and had undergone P/D were treated with pleural cavity irradiation that included a median dose of 52.2 Gy using helical tomotherapy. The median age of the patients was 53 years (31-74). In addition to clinical and diagnostic findings from regular follow-up examinations, we evaluated the dose distribution for other organs at risk to assess treatment in relation to toxicity, with special regard for the underlying intact lung.

RESULTS

The mean lung dose on the treatment site was 32.8 Gy (±6.8). The V_20 Gy was 71.7% (±17.2). No treatment-related toxicity that exceeded grade III according to common toxicity criteria (CTC) was observed. Median progression-free survival (PFS) was 13 months with a median overall survival (OAS) of 19 months.

CONCLUSION

The findings of this analysis provide data indicating that sparing the underlying lung in patients with MPM after P/D is not only feasible with helical tomotherapy, but that this treatment also causes reasonably few side effects.

Immunotherapy advances for mesothelioma treatment

INTRODUCTION

Mesothelioma is a rare type of cancer that is strongly tied to asbestos exposure. Despite application of different modalities such as chemotherapy, radiotherapy and surgery, patient prognosis remains very poor and therapies are ineffective. Much research currently focuses on the application of novel approaches such as immunotherapy towards this disease. Areas covered: The types, stages and aetiology of mesothelioma are detailed, followed by a discussion of the current treatment options such as radiotherapy, surgery, and chemotherapy. A description of innate and adaptive immunity and the principles and justification of immunotherapy is also included. Clinical trials for different immunotherapeutic modalities are described, and lastly the article closes with an expert commentary and five-year view, the former of which is summarised below. Expert commentary: Current efforts for novel mesothelioma therapies have been limited by attempting to apply treatments from other cancers, an approach which is not based on a solid understanding of mesothelioma biology. In our view, the influence of the hostile, hypoxic microenvironment and the gene expression and metabolic changes that resultantly occur should be characterised to improve therapies. Lastly, clinical trials should focus on overall survival rather than surrogate endpoints to avoid bias and inaccurate reflections of treatment effects.

Immunohistochemical evaluation of two antibodies against PD-L1 and prognostic significance of PD-L1 expression in epithelioid peritoneal malignant mesothelioma: A RENAPE study

BACKGROUND

Epithelioid peritoneal malignant mesothelioma (EPMM) is the most common subtype of this aggressive tumor. We compared two antibodies against PD-L1, a recent theranostic biomarker, and evaluated the prognostic value of PD-L1 expression by mesothelial and immune cells in EPMM.

METHODS

Immunohistochemistry was performed on 45 EPMM. Clinical and pathological data were extracted from the RENAPE database. Using E1L3N and SP142 clones, inter-observer agreement, PD-L1 expression by mesothelial and immune cells and inter-antibody agreement were evaluated. The prognostic relevance of PD-L1 expression was evaluated in 39 EPMM by univariate and multivariate analysis of overall survival (OS) and progression-free survival (PFS).

RESULTS

Inter-observer agreement on E1L3N immunostaining was moderate for mesothelial and immune cells, and fair for mesothelial and poor for immune cells using SP142. Using E1L3N, 31.1% of mesothelial and 15.6% of immune cells expressed PD-L1, and 22.2% of mesothelial and 26.7% of immune cells using SP142. Inter-antibody agreement was moderate. In most positive cases, 1-5% of tumor cells were positive. Using E1L3N, PD-L1 expression by lymphocytes was associated with better OS and PFS by both univariate and multivariate analysis. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy predicted better prognosis than other treatments. Solid subtype was an independent prognostic factor for worse OS.

CONCLUSION

E1L3N appeared easier to use than SP142 to evaluate PD-L1 expression. A minority of EPMM expressed PD-L1, and only a few cells were positive. PD-L1 expression by immune cells evaluated with E1L3N was an independent prognostic factor in EPMM.

Malignant pericardial mesothelioma : A systematic review of current practice

BACKGROUND

Malignant mesothelioma is a rare but aggressive tumor, with a high misdiagnosis rate and overall bleak prognosis. In 0.7% of all cases, the origin is the pericardium.

METHODS

The present study is a review of the literature published in recent decades focusing on the advances in clinical manifestations, radiological findings, diagnosis, differential diagnosis, and treatment of malignant pericardial mesothelioma (MPM).

RESULTS

No clear relationship has been established between the etiologies and the development of MPM. Clinical symptoms and signs are nonspecific when present. The main presentations are chest pain and dyspnea. Imaging plays an important role in the detection, characterization, staging, and posttreatment follow-up. The definitive diagnosis is made on the basis of pathological findings. Chest radiography and echocardiography are common techniques used initially, but their roles are limited. Computed tomography and magnetic resonance imaging have an advantage in depicting the thickened pericardium, mediastinal lymph node, tumor, and the extension of adjacent structures. Surgery is the most important treatment modality and remains palliative in most cases, while the roles of chemo- and radiotherapy are unsatisfactory.

CONCLUSION

Clinical trials of malignant pleural and peritoneal mesothelioma remain important for MPM management. Multimodality treatment of surgery, chemotherapy, radiotherapy, and immunotherapy is expected to have a role in the treatment of MPM.

Working with asbestos and the possible health risks

BACKGROUND

The generic term asbestos refers to a group of crystalline mineral silicates that occur naturally in various forms. Because of their properties of strength, heat and electrical resistance and their ability to withstand corrosion by acids and sea water, asbestos was used extensively both in the UK and worldwide.

AIMS

To provide a historical perspective of this ubiquitous occupational hazard, consider the key changes in UK legislation aimed at improving the management of this occupational health risk and describe the evidence from the scientific literature concerning asbestos and disease.

METHODS

Original articles, reviews (including reference textbooks) and scientific literature in PubMed and other principal medical science databases, 1960-2014, were searched. Publications by regulatory agencies and by governmental organizations were also considered and included where relevant.

RESULTS

Asbestos remains the biggest cause of cancer deaths worldwide. For malignant mesothelioma deaths alone, it is estimated that in the UK, between 2015 and 2020, the number of cases will peak at 2500 cases annually. It is not clear whether there is a safe level of asbestos fibres in air. Evidence for the efficacy of health surveillance is lacking.

CONCLUSIONS

Although the use of asbestos was banned in the UK in 1985 (amosite and crocidolite) and 1999 (chrysotile), it remains a significant occupational risk factor for work-related morbidity and mortality, causing both benign and malignant diseases, often with long latency. Further research is needed regarding exposure levels and health surveillance.

Recurrent hydropneumothorax: An unusual presentation for malignant pleural mesothelioma

Mesothelioma is a rare pulmonary malignancy commonly associated with asbestos exposure. Its presentation is insidious and non-specific, with complaints of chest pain, dyspnea and cough. Chest X-ray may demonstrate unilateral pleural effusion. CT and PET scans may highlight nodular pleural plaques. Diagnosis often times is difficult with negative imaging and negative pleural fluid studies. In rare cases, hydropneumothoraces may be seen. We report a case of malignant pleural mesothelioma presenting as recurrent hydropneumothorax with negative CT scan of the chest for pleural abnormalities and negative pleural fluid studies.

Chronic mesothelial reaction and toxicity of potassium octatitanate fibers in the pleural cavity in mice and F344 rats

Fiber‐shaped particles of potassium octatitanate (tradename TISMO; chemical formula K₂O·6TiO₂), which are morphologically similar to asbestos particles, were shown to induce severe proliferative reactions in the pleural mesothelium in a previous experiment carried out over 21 weeks. The present study aims to determine whether these fibers induce malignant mesotheliomas in rodents, and to examine chronic toxicity induced. Additionally, we investigated the specific differences observable between the biological responses to the direct infusion of the fibers alone into the pleural cavity and those induced by the co‐administration of the fibers with a known carcinogen. To detect the induction of malignant pleural mesotheliomas, two experiments were undertaken. In Experiment 1, four strains of mice, A/J, C3H, ICR, and C57BL, were examined for 52 weeks after experimental treatment with TISMO. In Experiment 2, the F344 rats were treated with TISMO alone, the lung carcinogen N‐bis (2‐hydroxypropyl) nitrosamine (DHPN) alone, both TISMO and DHPN, or left untreated and were then examined for 52 weeks. In this experiment, malignant lesion induction was expected in the co‐administration group. TISMO fibers were observed in the alveoli, indicating penetration through the visceral pleura in mice and rats. The histopathological detection of TISMO fibers in the liver and kidneys of mice and rats indicated migration of the fibers out of the pleural cavity. Atypical mesothelial cells with severe pleural proliferation were observed, but malignant mesotheliomas were not detected. Among the rats, there were no observed malignant alterations in the mesothelium induced by DHPN–TISMO co‐administration.

Positive TTF-1 Expression in Malignant Mesothelioma: A Case Report

BACKGROUND

The histopathological diagnosis of malignant mesothelioma is based mainly on the immunohistological profile of the neoplasia, using different immunohistochemical markers to distinguish between a malignant mesothelioma and a carcinoma.

CASE REPORT

A female patient presented with a right paravertebral rapidly growing tumor and severe pain. Based on the immunohistochemical findings, we present the first case of a malignant mesothelioma with immunohistochemical expression of thyroid transcription factor-1.

CONCLUSIONS

The detection of a positive reaction for thyroid transcription factor-1 in the tumor cells may not exclude a malignant mesothelioma.

Radiation-induced mesothelioma among long-term solid cancer survivors: a longitudinal analysis of SEER database

We investigated the association between external beam radiotherapy (EBRT) and pleural and peritoneal mesothelioma among long‐term (>5 years) solid cancer survivors. We analyzed data from the US Surveillance, Epidemiology, and End Results (SEER) program (1973–2012). We fitted survival models adjusted by age, gender, race, year, surgery, and relative risk of primary mesothelioma in the county of residence (proxy for individual asbestos exposure). We estimated hazard ratios [HR] with reference to nonirradiated patients. We distinguished between scattered and direct irradiation to study the dose–response. We observed 301 mesotheliomas (265 pleural; 32 peritoneal; 4 others) among 935,637 patients. EBRT increased the risk of mesothelioma (any site; HR 1.34, 95% CI 1.04–1.77). We observed an increased risk of pleural mesothelioma (HR for EBRT 1.34, 95% CI 1.01–1.77), but we did not find signs of a dose–response relationship (HR for scattered irradiation 1.38; HR for direct irradiation 1.23). On the opposite, only direct peritoneal irradiation was associated with peritoneal mesothelioma (HR 2.20, 95% CI 0.99–4.88), particularly for latencies ≥10 years (HR 3.28, 95% CI 1.14–9.43). A competing risks analysis revealed that the clinical impact of radiation‐induced mesothelioma was limited by the high frequency of competing events. The cumulative incidence function of mesothelioma after 40 years of observation was very low (nonirradiated patients 0.00032, irradiated patients 0.00055).EBRT might be a determinant of mesothelioma. Longer latency periods are associated with higher risks, while the dose–response seems nonlinear. The clinical impact of mesothelioma after EBRT for primary solid cancers is limited.

Malignant Mesothelioma Versus Metastatic Carcinoma of the Pleura: A CT Challenge

Background:

Malignant pleural mesothelioma (MPM) is a rare malignant neoplasm of the pleura that typically affects individuals occupationally exposed to asbestos through a variety of industries. MPM presents with several CT features similar to more common pleural diseases such as metastatic pleural malignancy.

Objectives:

The aim of this study is to differentiate malignant pleural mesothelioma from metastatic carcinoma of the pleura by pathological and radiological assessment in order to investigate accuracy of CT scan in this regard and to compare CT features of these two malignancies.

Patients and Methods:

Chest CT scans of 55 pleural malignancy patients including MPM and metastatic pleural malignancy were evaluated in this retrospective study. The pathologist made the definite diagnosis based on immunohistochemistry. A chest radiologist unaware of the pathology diagnosis observed all CT scans. Several parameters including pleural thickening, pleural effusion, thickening of inter lobar fissure, contralateral extension, contraction of involved hemithorax, parenchymal involvement (infiltration, nodules, fibrosis), pleural mediastinal involvement, lymphadenopathy, extrapleural invasion (hepatic, chest wall, diaphragm, intraperitoneal), and pericardial involvement were checked. Data analysis was carried out using SPSS version 16, and the ability of CT scan to differentiate malignant pleural mesothelioma and metastatic pleural diseases was investigated.

Results:

Totally 29 males and 26 females were assessed in this study. Based on pathology, 17 MPM and 38 metastatic pleural malignancies were diagnosed. According to CT study, about 82% of the patients with MPM and about 79% of the patients with metastatic pleural diseases were correctly diagnosed by a radiologist. The most common findings suggestive of MPM were pleural thickening (88.2%), loculated effusion (58.8%), and thickening of the interlobar fissure (47.1%). Whereas free pleural effusion (71.7%), parenchymal infiltration (65.8%) and pleural thickening (63.2%) were most prevalent parameters among metastatic cases.

Conclusion:

CT scan is highly accurate in differentiating malignant pleural mesothelioma and metastatic pleural diseases. Pleural thickening and thickening of interlobar fissure lead us to the diagnosis of MPM and massive free pleural effusion is more commonly seen in metastatic pleural malignancy.

Unusual lesions of the mediastinum

Objectives:

To study unusual lesions in the mediastinum, which do not originate from the thymus, lymph nodes, neural tissues or germ cells, and tissues that normally engender pathologic lesions in the mediastinum.

Materials and Methods:

Of the 65 cases seen, 12 unusual lesion were encountered in a 5½ year period from 2006 to 2011.

Results:

Two cases of nodular colloid goiter and one each of the mediastinal cyst, undifferentiated carcinoma, and Langerhans cell histiocytosis (LCH) affected the anterosuperior mediastinum. In the middle mediastinum, one case each of the mesothelioma, malignant gastrointestinal stromal tumor (GIST), squamous cell carcinoma (SCC), solitary fibrous tumor (SFT), and pleomorphic sarcoma (PS) was seen. One case of meningeal melanocytoma (Mme) and primary pleural liposarcoma (PL) involved the posterior mediastinum. Persistent disease was seen in LCH after 2 years. Of all the cases with malignant lesions, only the patient with SCC was alive after 1 year.

Conclusion:

The cases of primary and SCC, LCH, melanocytoma, liposarcoma and PS, and GIST are unexpected and very rarely have paradigms in the mediastinum. Radiologic impression and knowledge of the compartment where these lesions arose from hardly assisted in arriving at a definitive opinion as the lesions were not typical of this location. A high index of suspicion and the immunohistochemical profile facilitated the final diagnosis.

The Role of Ki-67 and Pre-cytoreduction Parameters in Selecting Diffuse Malignant Peritoneal Mesothelioma (DMPM) Patients for Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC)

BACKGROUND

We conducted a prognostic analysis of preoperative parameters and Ki-67 determination to develop selection criteria for cytoreductive surgery (CRS) and HIPEC in patients with diffuse malignant peritoneal mesothelioma (DMPM).

METHODS

DMPM patients treated with CRS and HIPEC at NCI of Milan participated in this study. Multivariate analysis was conducted using Cox proportional hazard model and conditional inference tree method to select independent predictors of overall survival (OS) from the followings pre-cytoreduction parameters: age, sex, ECOG performance status, Charlson comorbidity index, previous systemic chemotherapy, CA-125, histological subtype (epithelioid vs. biphasic/sarcomatoid), Ki-67 (determined with immunohistochemistry), and peritoneal cancer index (PCI).

RESULTS

A total of 117 patients (male/female: 67/50) with median age of 60.5 (range 22-75) years were included. Eighty-three patients had ECOG performance status = 0, median Charlson comorbidity index was 4 (range 2-9), and 102 cases had epithelioid subtype. Median Ki-67 was 5 % (range 1-60). Ninety-four (80.3 %) cases were optimally cytoreduced. The Cox analysis identified Ki-67, PCI, and histological subtype as independent prognosticators of OS. Conditional inference tree method identified three prognostic subsets: (I) Ki-67 ≤ 9 %; (II) Ki-67 > 9 % and PCI ≤ 17; and (III) Ki-67 > 9 % and PCI > 17. The median OS for subsets I, II, and III were, 86.6, 63.2, and 10.3 months, respectively.

CONCLUSIONS

Ki-67 is a powerful prognosticator that allows, along with PCI, and histological subtype, a good prediction of OS in patients with DMPM. Patients with Ki-67 > 9 % and PCI > 17 are unlikely to benefit from the procedure and should be considered for other treatment protocols.

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.