Anti-mesothelin immunotoxin induces mesothelioma eradication, anti-tumor immunity, and the development of tertiary lymphoid structures.

LMB-100 is a recombinant immunotoxin composed of a Fab linked to a toxin. It kills cells expressing human mesothelin (hMSLN), which is highly expressed on the surface of mesothelioma and many other cancer cells. Clinically, we observed some patients had delayed responses to an anti-hMSLN immunotoxin treatment, suggesting the induction of anti-tumor immunity. We aimed to develop a mouse model to investigate whether immunotoxin alone can induce anti-tumor immunity and to study the mechanism of this immunity. An immunocompetent transgenic mouse was used to grow mouse mesothelioma AB1 cells expressing hMSLN in the peritoneal cavity. Mice were treated with LMB-100, and mice with complete responses (CRs) were rechallenged with tumor cells to determine whether anti-tumor immunity developed. Changes in gene expression profiles were evaluated by Nanostring, and changes in cytokines and chemokines were checked by protein arrays. The distribution of various immune cells was assessed by immunohistochemistry. Our results show that the mice with tumor reached CRs and developed anti-tumor immunity after LMB-100 treatment alone. The primary response requires CD8+ T cells, CD4+ T cells, and B cells. Transcriptional profiling shows that LMB-100 treatment reshapes the tumor immune microenvironment by upregulating chemotaxis signals. LMB-100 treatment upregulates genes associated with tertiary lymphoid structures (TLS) development and induces TLS formation in tumors. In sum, immunotoxin-mediated cell death induces anti-tumor immunity and the development of TLS, which provides insights into how immunotoxins cause tumor regressions.

Dendritic cells loaded with allogeneic tumour cell lysate plus best supportive care versus best supportive care alone in patients with pleural mesothelioma as maintenance therapy after chemotherapy (DENIM): a multicentre, open-label, randomised, phase 2/3 study.

BACKGROUND: Dendritic cell immunotherapy has proven to be safe and induces an immune response in humans. We aimed to establish the efficacy of dendritic cells loaded with allogeneic tumour cell lysate (MesoPher, Amphera BV, 's-Hertogenbosch, Netherlands) as maintenance therapy in patients with pleural mesothelioma. METHODS: In this open-label, randomised, phase 2/3 study, patients with histologically confirmed unresectable pleural mesothelioma, aged 18 years or older, with an Eastern Cooperative Oncology Group performance status score of 0-1, and non-progressing disease after four to six cycles of standard chemotherapy (with pemetrexed 500 mg/m2 plus platinum [cisplatin 75 mg/m2 or carboplatin area under the curve of 5]) were recruited from four centres in Belgium, France, and The Netherlands. Participants were randomly assigned (1:1), using block randomisation (block size of 4), stratified by centre and histology (epithelioid vs other), to MesoPher treatment plus best supportive care or best supportive care alone. Patients received up to a maximum of five MesoPher infusions, with treatment administered on days 1, 15, and 29, and weeks 18 and 30. At each timepoint, participants received an injection of 25 × 106 dendritic cells (two-thirds of the dendritic cells were administered intravenously and a third were injected intradermally). Best supportive care was per local institutional standards. The primary endpoint was overall survival, assessed in all participants randomly assigned to treatment (full analysis set) and safety assessed in all randomly assigned participants, and who underwent leukapheresis if they were in the MesoPher group. This study is registered with ClinicalTrials.gov, NCT03610360, and is closed for accrual. FINDINGS: Between June 21, 2018, and June 10, 2021, 176 patients were screened and randomly assigned to the MesoPher group (n=88) or best supportive care alone group (n=88). One participant in the MesoPher group did not undergo leukapheresis. Mean age was 68 years (SD 8), 149 (85%) of 176 were male, 27 (15%) were female, 173 (98%) were White, two were Asian (1%), and one (1%) was other race. As of data cutoff (June 24, 2023), after a median follow up of 15·1 months (IQR 9·5-22·4), median overall survival was 16·8 months (95% CI 12·4-20·3; 61 [69%] of 88 died) in the MesoPher group and 18·3 months (14·3-21·9; 59 [67%] of 88 died) in the best supportive care group (hazard ratio 1·10 [95% CI 0·77-1·57]; log-rank p=0·62). The most common grade 3-4 treatment-emergent adverse events were chest pain (three [3%] of 87 in the MesoPher group vs two [2%] of 88 in the best supportive care group), dyspnoea (none vs two [2%]), anaemia (two [2%] vs none), nausea (none vs two [2%]), and pneumonia (none vs two [2%]). No deaths due to treatment-emergent adverse events were recorded. Treatment-related adverse events consisted of infusion-related reactions (fever, chills, and fatigue), which occurred in 64 (74%) of 87 patients in the MesoPher group, and injection-site reactions (itch, erythema, and induration), which occurred in 73 (84%) patients, and all were grade 1-2 in severity. No deaths were determined to be treatment related. INTERPRETATION: MesoPher did not show improvement in overall survival in patients with pleural mesothelioma. Immune checkpoint therapy is now standard of care in pleural mesothelioma. Further randomised studies are needed of combinations of MesoPher and immune checkpoint therapy, which might increase efficacy without adding major toxicities. FUNDING: Amphera BV and EU HORIZON.

p53 dry gene powder enhances anti-cancer effects of chemotherapy against malignant pleural mesothelioma.

Dry gene powder is a novel non-viral gene-delivery system, which is inhalable with high gene expression. Previously, we showed that the transfection of p16INK4a or TP53 by dry gene powder resulted in growth inhibitions of lung cancer and malignant pleural mesothelioma (MPM) in vitro and in vivo. Here, we report that dry gene powder containing p53- expression-plasmid DNA enhanced the therapeutic effects of cisplatin (CDDP) against MPM even in the presence of endogenous p53. Furthermore, our results indicated that the safe transfection with a higher plasmid DNA (pDNA) concentration suppressed MPM growth independently of chemotherapeutic agents. To develop a new therapeutic alternative for MPM patients without safety concerns over "vector doses", our in vitro data provide basic understandings for dry gene powder.

Combination of EZH2 and ATM inhibition in BAP1-deficient mesothelioma.

BACKGROUND: More than half of mesothelioma tumours show alterations in the tumour suppressor gene BAP1. BAP1-deficient mesothelioma is shown to be sensitive to EZH2 inhibition in preclinical settings but only showed modest efficacy in clinical trial. Adding a second inhibitor could potentially elevate EZH2i treatment efficacy while preventing acquired resistance at the same time. METHODS: A focused drug synergy screen consisting of 20 drugs was performed by combining EZH2 inhibition with a panel of anti-cancer compounds in mesothelioma cell lines. The compounds used are under preclinical investigation or already used in the clinic. The synergistic potential of the combinations was assessed by using the Bliss model. To validate our findings, in vivo xenograft experiments were performed. RESULTS: Combining EZH2i with ATMi was found to have synergistic potential against BAP1-deficient mesothelioma in our drug screen, which was validated in clonogenicity assays. Tumour growth inhibition potential was significantly increased in BAP1-deficient xenografts. In addition, we observe lower ATM levels upon depletion of BAP1 and hypothesise that this might be mediated by E2F1. CONCLUSIONS: We demonstrated the efficacy of the combination of ATM and EZH2 inhibition against BAP1-deficient mesothelioma in preclinical models, indicating the potential of this combination as a novel treatment modality using BAP1 as a biomarker.

FK228 suppress the growth of human malignant pleural mesothelioma tumor independent to epithelioid or non-epithelioid histology.

Human malignant pleural mesothelioma (hMPM) is an aggressive, rare disease with a poor prognosis. Histologically, MPM is categorized into epithelioid, biphasic, and sarcomatoid subtypes, with the epithelioid subtype generally displaying a better response to treatment. Conversely, effective therapies for the non-epithelioid subtypes are limited. This study aimed to investigate the potential role of FK228, a histone deacetylase inhibitor, in the suppression of hMPM tumor growth. We conducted a comprehensive analysis of the histological and molecular characteristics of two MPM cell lines, CRL-5820 (epithelioid) and CRL-5946 (non-epithelioid). CRL-5946 cells and non-epithelioid patient-derived xenografted mice exhibited heightened growth rates compared to those with epithelioid MPM. Both CRL-5946 cells and non-epithelioid mice displayed a poor response to cisplatin. However, FK228 markedly inhibited the growth of both epithelioid and non-epithelioid tumor cells in vitro and in vivo. Cell cycle analysis revealed FK228-induced G1/S and mitotic arrest in MPM cells. Caspase inhibitor experiments demonstrated that FK228-triggered apoptosis occurred via a caspase-dependent pathway in CRL-5946 but not in CRL-5820 cells. Additionally, a cytokine array analysis showed that FK228 reduced the release of growth factors, including platelet-derived and vascular endothelial growth factors, specifically in CRL-5946 cells. These results indicate that FK228 exhibits therapeutic potential in MPM by inducing cytotoxicity and modulating the tumor microenvironment, potentially benefiting both epithelioid and non-epithelioid subtypes.

Pembrolizumab plus chemotherapy versus chemotherapy in untreated advanced pleural mesothelioma in Canada, Italy, and France: a phase 3, open-label, randomised controlled trial.

BACKGROUND: Pleural mesothelioma usually presents at an advanced, incurable stage. Chemotherapy with platinum-pemetrexed is a standard treatment. We hypothesised that the addition of pembrolizumab to platinum-pemetrexed would improve overall survival in patients with pleural mesothelioma. METHODS: We did this open-label, international, randomised phase 3 trial at 51 hospitals in Canada, Italy, and France. Eligible participants were aged 18 years or older, with previously untreated advanced pleural mesothelioma, with an Eastern Cooperative Oncology Group performance status score of 0 or 1. Patients were randomly assigned (1:1) to intravenous chemotherapy (cisplatin [75 mg/m2] or carboplatin [area under the concentration-time curve 5-6 mg/mL per min] with pemetrexed 500 mg/m2, every 3 weeks for up to 6 cycles), with or without intravenous pembrolizumab 200 mg every 3 weeks (up to 2 years). The primary endpoint was overall survival in all randomly assigned patients; safety was assessed in all randomly assigned patients who received at least one dose of study therapy. This trial is registered with ClinicalTrials.gov, NCT02784171, and is closed to accrual. FINDINGS: Between Jan 31, 2017, and Sept 4, 2020, 440 patients were enrolled and randomly assigned to chemotherapy alone (n=218) or chemotherapy with pembrolizumab (n=222). 333 (76 %) of patients were male, 347 (79%) were White, and median age was 71 years (IQR 66-75). At final analysis (database lock Dec 15, 2022), with a median follow-up of 16·2 months (IQR 8·3-27·8), overall survival was significantly longer with pembrolizumab (median overall survival 17·3 months [95% CI 14·4-21·3] with pembrolizumab vs 16·1 months [13·1-18·2] with chemotherapy alone, hazard ratio for death 0·79; 95% CI 0·64-0·98, two-sided p=0·0324). 3-year overall survival rate was 25% (95% CI 20-33%) with pembrolizumab and 17% (13-24%) with chemotherapy alone. Adverse events related to study treatment of grade 3 or 4 occurred in 60 (27%) of 222 patients in the pembrolizumab group and 32 (15%) of 211 patients in the chemotherapy alone group. Hospital admissions for serious adverse events related to one or more study drugs were reported in 40 (18%) of 222 patients in the pembrolizumab group and 12 (6%) of 211 patients in the chemotherapy alone group. Grade 5 adverse events related to one or more drugs occurred in two patients on the pembrolizumab group and one patient in the chemotherapy alone group. INTERPRETATION: In patients with advanced pleural mesothelioma, the addition of pembrolizumab to standard platinum-pemetrexed chemotherapy was tolerable and resulted in a significant improvement in overall survival. This regimen is a new treatment option for previously untreated advanced pleural mesothelioma. FUNDING: The Canadian Cancer Society and Merck & Co.

A randomised phase II study of extended pleurectomy/decortication preceded or followed by chemotherapy in patients with early-stage pleural mesothelioma: EORTC 1205.

BACKGROUND: The role of surgery in pleural mesothelioma remains controversial. It may be appropriate in highly selected patients as part of a multimodality treatment including chemotherapy. Recent years have seen a shift from extrapleural pleuropneumonectomy toward extended pleurectomy/decortication. The most optimal sequence of surgery and chemotherapy remains unknown. METHODS: EORTC-1205-LCG was a multicentric, noncomparative phase 2 trial, 1:1 randomising between immediate (arm A) and deferred surgery (arm B), followed or preceded by chemotherapy. Eligible patients (Eastern Cooperative Oncology Group 0-1) had treatment-naïve, borderline resectable T1-3 N0-1 M0 mesothelioma of any histology. Primary outcome was rate of success at 20 weeks, a composite end-point including 1) successfully completing both treatments within 20 weeks; 2) being alive with no signs of progressive disease; and 3) no residual grade 3-4 toxicity. Secondary end-points were toxicity, overall survival, progression-free survival and process indicators of surgical quality. FINDINGS: 69 patients were included in this trial. 56 (81%) patients completed three cycles of chemotherapy and 58 (84%) patients underwent surgery. Of the 64 patients in the primary analysis, 21 out of 30 patients in arm A (70.0%; 80% CI 56.8-81.0%) and 17 out of 34 patients (50.0%; 80% CI 37.8-62.2%) in arm B reached the statistical end-point for rate of success. Median progression-free survival and overall survival were 10.8 (95% CI 8.5-17.2) months and 27.1 (95% CI 22.6-64.3) months in arm A, and 8.0 (95% CI 7.2-21.9) months and 33.8 (95% CI 23.8-44.6) months in arm B. Macroscopic complete resection was obtained in 82.8% of patients. 30- and 90-day mortality were both 1.7%. No new safety signals were found, but treatment-related morbidity was high. INTERPRETATION: EORTC 1205 did not succeed in selecting a preferred sequence of pre- or post-operative chemotherapy. Either procedure is feasible with a low mortality, albeit consistent morbidity. A shared informed decision between surgeon and patient remains essential.

Tretinoin improves the anti-cancer response to cyclophosphamide, in a model-selective manner.

BACKGROUND: Chemotherapy is included in treatment regimens for many solid cancers, but when administered as a single agent it is rarely curative. The addition of immune checkpoint therapy to standard chemotherapy regimens has improved response rates and increased survival in some cancers. However, most patients do not respond to treatment and immune checkpoint therapy can cause severe side effects. Therefore, there is a need for alternative immunomodulatory drugs that enhance chemotherapy. METHODS: We used gene expression data from cyclophosphamide (CY) responders and non-responders to identify existing clinically approved drugs that could phenocopy a chemosensitive tumor microenvironment (TME), and tested combination treatments in multiple murine cancer models. RESULTS: The vitamin A derivative tretinoin was the top predicted upstream regulator of response to CY. Tretinoin pre-treatment induced an inflammatory, interferon-associated TME, with increased infiltration of CD8 + T cells, sensitizing the tumor to subsequent chemotherapy. However, while combination treatment significantly improved survival and cure rate in a CD4+ and CD8+ T cell dependent manner in AB1-HA murine mesothelioma, this effect was model-selective, and could not be replicated using other cell lines. CONCLUSIONS: Despite the promising data in one model, the inability to validate the efficacy of combination treatment in multiple cancer models deprioritizes tretinoin/cyclophosphamide combination therapy for clinical translation.

Mesothelioma-Associated Fibroblasts Modulate the Response of Mesothelioma Patient-Derived Organoids to Chemotherapy via Interleukin-6.

Malignant pleural mesothelioma (MPM) remains an incurable disease. This is partly due to the lack of experimental models that fully recapitulate the complexity and heterogeneity of MPM, a major challenge for therapeutic management of the disease. In addition, the contribution of the MPM microenvironment is relevant for the adaptive response to therapy. We established mesothelioma patient-derived organoid (mPDO) cultures from MPM pleural effusions and tested their response to pemetrexed and cisplatin. We aimed to evaluate the contribution of mesothelioma-associated fibroblasts (MAFs) to the response to pemetrexed and cisplatin (P+C). Organoid cultures were obtained from eight MPM patients using specific growth media and conditions to expand pleural effusion-derived cells. Flow cytometry was used to verify the similarity of the organoid cultures to the original samples. MAFs were isolated and co-cultured with mPDOs, and the addition of MAFs reduced the sensitivity of mPDOs to P+C. Organoid formation and expression of cancer stem cell markers such as ABCG2, NANOG, and CD44 were altered by conditioned media from treated MAFs. We identified IL-6 as the major contributor to the attenuated response to chemotherapy. IL-6 secretion by MAFs is correlated with increased resistance of mPDOs to pemetrexed and cisplatin.

[Interdisciplinary diagnostics and therapy of malignant mesothelioma]. / Interdisziplinäre Diagnostik und Therapie von malignen Mesotheliomen.

The asbestos-related malignant mesothelioma (MM) is one of the common occupational cancers in Germany with approximately 1000 new cases per year. Provided that the appropriate diagnostic criteria are fulfilled, MM can be diagnosed with high specificity from both histological and cytological specimens. However, many MM are detected cyto-/histologically only at advanced stages. Clinical/radiological aspects complement each other and enable interdisciplinary assessment of tumor stage and individualized decisions on the best possible therapeutic options. Diagnostically, video-assisted thoracoscopy (VATS) has the highest priority. Therapy planning is based on the MM subtype, tumor spread and stage, and the patient's clinical condition. MM has generally a very unfavorable prognosis. Accordingly, the standard therapy aims at a macroscopic radical tumor resection in terms of cytoreduction within the framework of a suitable multimodal therapy concept (chemotherapy, radiotherapy, psychooncology). The aim of palliative measures should be primarily symptom control. Overall, interdisciplinary diagnosis and therapy of MM is crucial for the best possible care of MM patients.

[Survival analysis of 37 cases of malignant mesothelioma].

Objective: To explore the relationship between clinicopathological features, treatment and prognosis of patients with malignant mesothelioma, and provide theoretical basis for the prevention and treatment of malignant mesothelioma. Methods: In November 2022, the clinical data of 37 patients with malignant mesothelioma diagnosed in Qingdao Central Hospital from July 2014 to November 2022 were retrospectively analyzed, and the prognostic factors were analyzed by Kaplan-Meier and log-rank tests. Results: The median age of the 37 patients was 66 years old, all patients were confirmed by pathology. The median survival time of all patients was 30.00 months. The 1-year, 2-year, 3-year and 5-year cumulative survival rates were 70.27% (26/37), 48.65% (18/37), 16.22% (6/37) and 13.51% (5/37), respectively. Compared with different treatments, the median survival time of palliative care patients was 5.00 months, which was significantly lower than that of operation group (30.33 months), chemotherapy group (30.00 months), surgery combined with chemotherapy group (30.00 months) and chemotherapy combined with bevacizumab targeted therapy group (47.42 months) (P<0.05). Gender, age (≥60 years old or <60 years old), smoking history, occupational exposure history, disease site, and surgical history were not factors affecting the survival of malignant mesothelioma patients (P>0.05) . Conclusion: The clinical symptoms of malignant mesothelioma are not specific, but early initiation of treatment can still prolong survival, and chemotherapy combined with anti-vascular targeted therapy shows better therapeutic effect.

[Correlation between prognostic nutritional index and pleural thickness with survival time of epithelial malignant pleural mesothelioma patients].

Objective: To explore the role of prognostic nutritional index (PNI) and pleural thickness in the prognostic evaluation of patients with epithelial malignant pleural mesothelioma (MPM) . Methods: In April 2022, a retrospective analysis was conducted on the data and laboratory data of 41 patients with epithelial MPM admitted to the cardiothoracic surgery department of Chuxiong Yi Autonomous Prefecture People's Hospital from January 2018 to May 2021. Univariate and multivariate analysis were used to evaluate the relationships between total survival time, clinical characteristics, PNI and pleural thickness in patients. Results: The 41 patients were mostly male (26 cases, 63.4%) , with a median age of 55 years old. The main clinical manifestations were chest pain (53.7%) , bloody pleural effusion (75.6%) , and chest pain combined with bloody pleural effusion (36.6%) . The median survival time of patients with different TNM stage, efficacy after 4 cycles of chemotherapy, PNI, maximum pleural thickness after chemotherapy (post max) , sum of post max in 3 zones after chemotherapy (post sum) were statistically different (χ(2)=3.89, 14.51, 15.33, 4.33, 12.05, P<0.05) . Compared with patients with high PNI and post sum<32.26 mm, MPM patients with low PNI and post sum≥32.26 mm have higher risk of death, and the differences were statistically significant (HR=1.52, 95%CI: 1.75-11.93, P=0.002; HR=1.70, 95%CI: 1.84-16.23, P=0.002) . Conclusion: PNI and post sum can be used to predict the prognosis of patients with epithelial MPM.

Clinical Efficacy and Safety of Nivolumab in Malignant Non-Pleural Mesothelioma: A Multicenter, Open-Label, Single-Arm, Japanese Phase II Trial (Viola) Protocol.

BACKGROUND: There is no authorized treatment for malignant non-pleural mesothelioma (MNPM) worldwide. In contrast to malignant pleural mesothelioma, MNPM has not been investigated, and no treatment has been established due to its rarity. OBJECTIVES: This multicenter, open-label, single-arm, Japanese phase II trial aims at evaluating the efficacy and safety of nivolumab, an immune checkpoint inhibitor, in advanced or metastatic MNPM treatment. METHODS: This phase II trial commenced in October 2020. Twenty-three patients with advanced or metastatic MNPM who meet the inclusion and exclusion criteria were enrolled from five institutions within 2 years. Regardless of prior therapy, 240 mg of nivolumab will be administered intravenously to MNPM patients every 2 weeks to investigate its efficacy and safety until disease progression or unacceptable toxicities are detected, or the patient's condition meets the withdrawal criteria. RESULTS: The primary endpoint is the objective response rate by central assessment following the Response Evaluation Criteria in Solid Tumors version 1.1. The secondary endpoints include disease control rate, overall survival, progression-free survival, adverse events, and treatment-related adverse events. CONCLUSIONS: This is the first prospective investigator-initiated trial to evaluate the effect of nivolumab monotherapy for MNPM.

LAG3 is an independent prognostic biomarker and potential target for immune checkpoint inhibitors in malignant pleural mesothelioma: a retrospective study.

BACKGROUND: Lymphocyte-activation gene 3 (LAG3) is an immune checkpoint receptor; novel LAG3 immune checkpoint inhibitors (ICIs) exhibit therapeutic activity in melanoma. The role of LAG3and ICIs of LAG3 are unknown in malignant pleural mesothelioma (MPM). This study aimed to uncover the prognostic landscape of LAG3 in multiple cancers and investigate the potential of using LAG3 as an ICIs target in patients with MPM. METHODS: We used The Cancer Genome Atlas (TCGA) cohort for assessing mRNA expression and our cohort for immunohistochemical expression. TCGA cohort were analyzed using the Wilcoxon rank-sum test to compare mRNA expression between normal and tumor tissues in multiple cancers. We used 86 MPM cases from TCGA and 38 MPM cases from our cohort to analyze the expression of LAG3 in tumor-infiltrating lymphocytes. The mean LAG3 mRNA expression was set as the cut-off and samples were classified as positive/negative for immunohistochemical expression. Overall survival (OS) of patients with MPM was determined using the Kaplan-Meier method based on LAG3 mRNA and immunohistochemical expression. OS analysis was performed using the multivariate Cox proportional hazards model. The correlation of LAG3 expression and mRNA expression of tumor immune infiltration cells (TIICs) gene markers were estimated using Spearman correlation. To identify factors affecting the correlation of LAG3 mRNA expression, a multivariate linear regression model was performed. RESULTS: LAG3 mRNA was associated with prognosis in multiple cancers. Elevated LAG3 mRNA expression was correlated with a better prognosis in MPM. LAG3 expression was detected immunohistochemically in the membrane of infiltrating lymphocytes in MPM. LAG3 immunohistochemical expression was correlated with a better prognosis in MPM. The multivariate Cox proportional hazards model revealed that elevated LAG3 immunohistochemical expression indicated a better prognosis. In addition, LAG3 mRNA expression was correlated with the expression of various gene markers of TIICs, the most relevant to programmed cell death 1 (PD-1) with the multivariate linear regression model in MPM. CONCLUSIONS: LAG3 expression was correlated with prognosis in multiple cancers, particularly MPM; LAG3 is an independent prognostic biomarker of MPM. LAG3 regulates cancer immunity and is a potential target for ICIs therapy. PD-1 and LAG3 inhibitors may contribute to a better prognosis in MPM. TRIAL REGISTRATION: This study was registered with UMIN000049240 (registration day: August 19, 2022) and approved by the Institutional Review Board (approval date: August 22, 2022; approval number: 2022-0048) at Tokyo Women's Medical University.

Laser ablation-inductively coupled plasma-mass spectrometry analysis reveals differences in chemotherapeutic drug distribution in surgically resected pleural mesothelioma.

AIMS: Pleural mesothelioma (PM) is a highly aggressive thoracic tumour with poor prognosis. Although reduced tissue drug accumulation is one of the key features of platinum (Pt) resistance, little is known about Pt distribution in human PM. METHODS: We assessed Pt levels of blood samples and surgically resected specimens from 25 PM patients who had received neoadjuvant Pt-based chemotherapy (CHT). Pt levels and tissue distributions were measured by laser ablation-inductively coupled plasma-mass spectrometry and correlated with clinicopathological features. RESULTS: In surgically resected PM specimens, mean Pt levels of nontumourous (fibrotic) areas were significantly higher (vs tumourous regions, P = 0.0031). No major heterogeneity of Pt distribution was seen within the tumourous areas. Pt levels correlated neither with the microvessel area nor with apoptosis rate in the tumourous or nontumourous regions. A significant positive correlation was found between serum and both full tissue section and tumourous area mean Pt levels (r = 0.532, P = 0.006, 95% confidence interval [95% CI] 0.161-0.771 and r = 0.415, P = 0.039, 95% CI 0.011-0.702, respectively). Furthermore, a significant negative correlation was detected between serum Pt concentrations and elapsed time from the last cycle of CHT (r = -0.474, P = 0.017, 95% CI -0.738--0.084). Serum Pt levels correlated negatively with overall survival (OS) (P = 0.029). CONCLUSIONS: There are major differences in drug distribution between tumourous and nontumourous areas of PM specimens. Serum Pt levels significantly correlate with full section and tumourous area average Pt levels, elapsed time from the last CHT cycle, and OS. Further studies investigating clinicopathological factors that modulate tissue Pt concentration and distribution are warranted.

Contemporary issues in the surgical management of pleural mesothelioma.

The surgical management of pleural mesothelioma (PM) can be divided into diagnostic, staging, palliation, and cytoreductive surgery. In the cytoreductive surgical setting, the combination of different treatment modalities has led to better outcomes than surgery alone. The scarcity of high-quality studies has led to heterogeneity in management of PM across the mesothelioma treatment centers. Here, we review the literature regarding the most important open questions and ongoing clinical trials.

High-dose IV magnesium in mesothelioma patients receiving surgery with hyperthermic intraoperative cisplatin: Pilot studies and design of a phase II randomized clinical trial.

INTRODUCTION: Hyperthermic intraoperative cisplatin (HIOC) is associated with acute kidney injury (AKI). Administration of high-dose magnesium attenuates cisplatin-induced AKI (CP-AKI) in animal models but has not been rigorously examined in humans. METHODS: We tested the feasibility and safety of different doses of magnesium in mesothelioma patients receiving HIOC. In Pilot Study 1, we administered a 36-h continuous infusion of magnesium at 0.5 g/h, targeting serum magnesium levels between 3 and 4.8 mg/dL. In Pilot Study 2A, we administered a 6 g bolus followed by an infusion starting at 2 g/h, titrated to achieve levels between 4 and 6 mg/dL. We eliminated the bolus in Pilot Study 2B. RESULTS: In Pilot Study 1, all five patients enrolled completed the study; however, median postoperative Mg levels were only 2.4 mg/dL. In Pilot Study 2A, two of four patients (50%) were withdrawn due to bradycardia during the bolus. In Pilot Study 2B, two patients completed the study whereas two developed postoperative bradycardia attributed to the magnesium. CONCLUSIONS: A 0.5 g/h infusion for 36 h did not achieve therapeutic magnesium levels, while an infusion at 2 g/h was associated with bradycardia. These studies informed the design of a randomized clinical trial testing whether intravenously Mg attenuates HIOC-associated AKI.

Predictive factors associated with pemetrexed acute toxicity.

PURPOSE: Pemetrexed has shown efficacy as monotherapy or in combination with platinum salts in the treatment of non-small cell lung cancer and mesothelioma. However, severe hematological toxicities induced by pemetrexed-based chemotherapy have been observed. Some studies have suggested that drug interactions may be associated with pemetrexed toxicity. The objective of this study was to determine predictive factors, including drug interactions, associated with pemetrexed toxicity. METHODS: This retrospective open monocentric study included patients consecutively treated with pemetrexed after a multidisciplinary risk assessment. Patients who experienced toxicity of grade 3 or 4 according to the Common Terminology Criteria for Adverse Events v5.0, or a grade 2 leading to a change in management, during the first four courses of pemetrexed, were assigned to the early limiting toxicities (ELT) group. Univariate and multivariable logistic regression models were used to test the association variables with the occurrence of ELT. RESULTS: Seventy-four patients were included in this study (median age: 67 years, with non-small cell lung cancer adenocarcinoma (88%), mesothelioma (7%), or others (5%). Thirty-six patients (49%) were assigned to the ELT group (27 grades 3 and 4; 9 grade 2 with management modification). Three baseline factors were associated with pemetrexed ELT in univariate and multivariate analysis: cystatin clearance (p = 0.0135), albumin level (p = 0.0333), and proton pump inhibitors use (p = 0.035). CONCLUSION: To conclude, ELT induced by pemetrexed-based treatments occur frequently in cancer patients in a real-world setting. A pretherapeutic assessment before pemetrexed initiation should include three major checkpoints: use of proton pump inhibitors, sarcopenia, and denutrition evaluation.

SPC212 human mesothelioma cells underwent apoptosis, oxidative stress, and morphological deformation following Astaxanthin treatment.

Astaxanthin (ASX) is one of the keto-carotenoids, which is biologically more active than other counterparts. Besides its variety of beneficial effects, it was reported to exert anticancer effects. Despite its utilization against different cancer types, the effect of ASX on mesothelioma has yet to be well-studied. In this study, our goal is to ascertain how ASX will affect SPC212 human mesothelioma cells. First, the effective doses of ASX against SPC212 cells were investigated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. Thereafter, with flow cytometry analysis, Annexin-V and caspase 3/7 assay were implemented for the evaluation of apoptotic cell death and an oxidative stress test was carried out to determine how the free radicals changed. Ultimately, the cells' morphology was examined under a light microscope. The effective doses of ASX were found as 50, 100, and 200 µM. In the Annexin V assay, the total apoptosis increased to around 12%, 30%, and 45% with increasing doses of ASX. In the caspase 3/7 assay, the total apoptosis was around 25% and 38% at 100 and 200 µM. In oxidative stress analysis, reactive oxygen species-positive cells rose from 4.54 at the lowest dose to 86.95 at the highest dose. In morphological analysis, cellular shrinkage, decrease in cell density, swelling and vacuolations in some cells, membrane blebbing, and apoptotic bodies are observed in ASX-treated cells. To conclude, the current study provided insights into the efficacy and effects of ASX against SPC212 mesothelioma cells regarding morphology, proliferation, and cell death for future studies.

Establishment of a Bayesian network model to predict the survival of malignant peritoneal mesothelioma patients after cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy.

OBJECTIVES: To establish a Bayesian network (BN) model to predict the survival of patients with malignant peritoneal mesothelioma (MPM) treated with cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC). METHODS: The clinicopathological data of 154 MPM patients treated with CRS + HIPEC at our hospital from April 2015 to November 2022 were retrospectively analyzed. They were randomly divided into two groups in a 7:3 ratio. Survival analysis was conducted on the training set and a BN model was established. The accuracy of the model was validated using a confusion matrix of the testing set. The receiver operating characteristic (ROC) curve and area under the curve were used to evaluate the overall performance of the BN model. RESULTS: Survival analysis of 107 patients (69.5%) in the training set found ten factors affecting patient prognosis: age, Karnofsky performance score, surgical history, ascites volume, peritoneal cancer index, organ resections, red blood cell transfusion, pathological types, lymphatic metastasis, and Ki-67 index (all p < 0.05). The BN model was successfully established after the above factors were included, and the BN model structure was adjusted according to previous research and clinical experience. The results of confusion matrix obtained by internal validation of 47 cases in the testing set showed that the accuracy of BN model was 72.7%, and the area under ROC was 0.74. CONCLUSIONS: The BN model was established successfully with good overall performance and can be used as a clinical decision reference.