bims-mesote Biomed News
on Mesothelioma
Issue of 2021–04–11
five papers selected by
Laura Mannarino, Humanitas Research



  1. Front Oncol. 2021 ;11 653497
       Introduction: The CDKN2A gene plays a central role in the pathogenesis of malignant pleural mesothelioma (MPM). The gene encodes for two tumor suppressor proteins, p16/INK4A and p14/ARF, frequently lost in MPM tumors. The exact role of p14/ARF in MPM and overall its correlation with the immune microenvironment is unknown. We aimed to determine whether there is a relationship between p14/ARF expression, tumor morphological features, and the inflammatory tumor microenvironment.
    Methods: Diagnostic biopsies from 76 chemo-naive MPMs were evaluated. Pathological assessments of histotype, necrosis, inflammation, grading, and mitosis were performed. We evaluated p14/ARF, PD-L1 (tumor proportion score, TPS), and Ki-67 (percentage) by immunohistochemistry. Inflammatory cell components (CD3+, CD4+, CD8+ T lymphocytes; CD20+ B-lymphocytes; CD68+ and CD163+ macrophages) were quantified as percentages of positive cells, distinguishing between intratumoral and peritumoral areas. The expression of p14/ARF was associated with several clinical and pathological characteristics. A random forest-based machine-learning algorithm (Boruta) was implemented to identify which variables were associated with p14/ARF expression.
    Results: p14/ARF was evaluated in 68 patients who had a sufficient number of tumor cells. Strong positivity was detected in 14 patients (21%) (11 epithelioid and 3 biphasic MPMs). At univariate analysis, p14/ARF-positive epithelioid mesotheliomas showed higher nuclear grade (G3) (p = 0.023) and higher PD-L1 expression (≥50%) (p = 0.042). The percentages of CD4 and CD163 in peritumoral areas were respectively higher and lower in p14/ARF positive tumors but did not reach statistical significance with our sample size (both p = 0.066). The Boruta algorithm confirmed the predictive value of PD-L1 percentage for p14/ARF expression in all histotypes.
    Conclusions: p14/ARF-positive epithelioid mesotheliomas may mark a more aggressive pathological phenotype (higher nuclear grade and PD-L1 expression). Considering the results regarding the tumor immune microenvironment, p14/ARF-negative tumors seem to have an immune microenvironment less sensitive to immune checkpoint inhibitors, being associated with low PD-L1 and CD4 expression, and high CD163 percentage. The association between p14/ARF-positive MPMs and PD-L1 expression suggests a possible interaction of the two pathways. Confirmation of our preliminary results could be important for patient selection and recruitment in future clinical trials with anticancer immunotherapy.
    Keywords:  MPM; immune microenvironment; malignant pleural mesothelioma; p14/ARF; tumor microenvironment
    DOI:  https://doi.org/10.3389/fonc.2021.653497
  2. Clin Transl Oncol. 2021 Apr 10.
       BACKGROUND: Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor, with a poor prognosis. MPM needs to find prognostic factors of survival. We provided the management of patients with MPM and sought to determine whether pre-treatment levels of derived neutrophil-to-lymphocyte ratio (dNLR) as well as PD-L1 expression were reliable prognostic factors of survival.
    METHODS: We conducted a single-institution retrospective study, including all patients with MPM treated at La Paz University Hospital between December 2009 and March 2018. Baseline disease, demographics, clinical data, treatment characteristics and complete blood cell counts were collected. We examined dNLR at baseline and data for PD-L1 expression were analyzed in tumor cells by immunohistochemistry.
    RESULTS: We included 25 patients. The median overall survival (OS) was 15.7 months (95% CI 11.3-20.0). 5 patients had a dNLR greater than 3 (20%). Patients with a dNLR greater than 3 had shorter median OS (8.5 months), than patients with a dNLR less than 3 (17.0 months), with statistically significant differences (p = 0.038). Ten patients (40%) had positive PD-L1 expression (≥ 1%). Patients with positive PD-L1 expression had shorter median OS (8.5 months) than patients with negative PDL1 expression (15.7 months), but without statistically significant association (p = 0.319).
    CONCLUSION: The survival data obtained in our sample are consistent with those previously reported. Pretreatment levels of dNLR greater than 3 and positive PD-L1 expression could be significant prognostic factors for poor survival in patients with MPM. Further and prospective studies are needed to explore this relationship and to derive definitive conclusions.
    Keywords:  Derived neutrophil-to-lymphocyte ratio; Malignant pleural mesothelioma; PD-L1 expression
    DOI:  https://doi.org/10.1007/s12094-021-02605-w
  3. Thorac Cancer. 2021 Apr 08.
       BACKGROUND: Treatment options for malignant pleural mesothelioma (MPM) are limited. Anthracyclines are considered key drugs for treating MPM. However, their use is limited by severe cardiac toxicities. Amrubicin (AMR) is a next-generation anthracycline that is commonly used to treat lung cancer. Here, we conducted a phase II trial of this drug in patients with previously treated MPM.
    METHODS: Eligible patients with MPM having adequate organ function and a performance status of 0-2 were enrolled after disease progression following pemetrexed/platinum therapy. Patients received 35 mg/m2 AMR on days 1-3 every three weeks until tumor progression or the appearance of unacceptable toxicities. The primary endpoint was the objective response rate. Median progression-free survival (PFS), overall survival (OS), number of treatment cycles, and adverse events were evaluated as secondary endpoints.
    RESULTS: This trial was discontinued because of low accrual. From September 2013 to July 2018, five patients with MPM were enrolled. Stable disease (SD) was observed in three patients (60%), and progressive disease was noted in two patients (40%). The median PFS was 2.4 (range, 1.2-11.2) months, and the median OS was 9.1 (range, 6.2-22.0) months. The median number of treatment cycles was three (range, 2-11). Grade 1/2 toxicities were observed in all patients. Grade 3/4 neutropenia was observed in four patients (80%), but there were no cases of febrile neutropenia.
    CONCLUSIONS: Despite the absence of the responders, the observation of SD in three patients suggests that AMR could have potential for treating MPM.
    Keywords:  amrubicin; anthracyclines; case series; malignant pleural mesothelioma
    DOI:  https://doi.org/10.1111/1759-7714.13892
  4. Respir Med Case Rep. 2021 ;33 101381
      Pleural mesothelioma is a disease with a very poor prognosis. Here, we report a mesothelioma patient who survived for 5 years and a half. As a result of the autopsy, the tumor was diagnosed as a myxoid variant, which is internationally proposed as a histological subtype of epithelioid mesothelioma with a relatively favorable prognosis. Since patients with this disease are expected to survive for a long period even without treatment, careful determination of the therapeutic approach is considered necessary. This report is considered to be the first of a myxoid variant epithelioid pleural mesothelioma in Japan.
    Keywords:  Epithelioid mesothelioma; Female; Long-term survival; Myxoid variant; No history of asbestos exposure
    DOI:  https://doi.org/10.1016/j.rmcr.2021.101381
  5. Lancet Respir Med. 2021 Apr 06. pii: S2213-2600(20)30515-4. [Epub ahead of print]
       BACKGROUND: Malignant pleural mesothelioma (MPM) has few treatment options. Pembrolizumab showed preliminary clinical benefit in programmed death ligand 1 (PD-L1)-positive MPM. We evaluated the efficacy and safety of pembrolizumab monotherapy in patients with previously treated MPM irrespective of PD-L1 status in the KEYNOTE-158 study.
    METHODS: The ongoing open-label, multicohort, single-arm, phase 2 KEYNOTE-158 study enrolled eligible adults (≥18 years) with MPM who had progression on or intolerance to standard therapy, Eastern Cooperative Oncology Group performance status 0-1, and biomarker-evaluable tumour samples. Individuals were enrolled from 35 academic facilities and community-based institutions across 14 countries in Australia, North America, Europe, and Asia. Participants received pembrolizumab 200 mg intravenously every 3 weeks for up to 35 cycles. The primary efficacy endpoint was objective response per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, based on radiological imaging every 9 weeks for the first year of the study and every 12 weeks thereafter and assessed by independent central review. Efficacy and safety were analysed in all patients who received at least one dose of pembrolizumab. This trial is registered with ClinicalTrials.gov, NCT02628067.
    FINDINGS: Patients were enrolled in the MPM cohort between Feb 9, 2016, and Aug 16, 2016. As of June 27, 2019, 118 patients had been enrolled and received at least one dose of pembrolizumab. Ten (8% [95% CI 4-15]) patients had an objective response. Median duration of objective response was 14·3 months (range 4·0 to 33·9+), and 60% of objective responses were ongoing at 12 months. Objective responses were observed in six (8%) of 77 patients with PD-L1-positive MPM (median response duration 17·7 months [range 5·8 to 33·9+]) and four (13%) of 31 patients with PD-L1-negative MPM (10·2 months [4·0-16·6]). Median overall survival was 10·0 months (95% CI 7·6-13·4) and median progression-free survival was 2·1 months (2·1-3·9). Treatment-related adverse events occurred in 82 (69%) of 118 patients and serious adverse events that were considered to be treatment-related occurred in 14 (12%) of 118 patients. 19 (16%) patients had grade 3-4 treatment-related events, and most common of these were colitis (three patients), hyponatraemia (three), and pneumonitis (two). One patient died from treatment-related apnoea. By the end of the trial, 113 (96%) patients had discontinued pembrolizumab and progressive disease was the most common reason for discontinuation.
    INTERPRETATION: Pembrolizumab showed durable antitumour activity and manageable toxicity in patients with advanced MPM, regardless of PD-L1 status. Our data support the programmed death 1 (PD-1) and PD-L1 pathway as a potential therapeutic target in some patients with previously treated mesothelioma but biomarkers that can effectively identify such patients are yet to be elucidated.
    FUNDING: Merck Sharp & Dohme Corp, a subsidiary of Merck & Co, Inc, Kenilworth, NJ, USA.
    DOI:  https://doi.org/10.1016/S2213-2600(20)30515-4