bims-mesote Biomed News
on Mesothelioma
Issue of 2024–05–26
six papers selected by
Laura Mannarino, Humanitas Research



  1. Int J Mol Sci. 2024 May 14. pii: 5355. [Epub ahead of print]25(10):
      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.
    Keywords:  IL-6; PDO; chemoresistance; cisplatin; cocultures; mesothelioma patient-derived organoids; mesothelioma-associated fibroblasts; pemetrexed
    DOI:  https://doi.org/10.3390/ijms25105355
  2. Pathol Res Pract. 2024 May 14. pii: S0344-0338(24)00261-9. [Epub ahead of print]259 155350
      Fluoroedenite-induced pleural mesothelioma (FE-induced-PM) is a rare and small subset of PM that shares with its asbestos-induced counterpart the same aggressive biological behavior and poor prognosis, but that differs from it from a pathogenetic point of view as it is associated with exposure to fluoroedenite, a carcinogenic agent that shows similarities with tremolite amphibolic asbestos fibers. Although it has been demonstrated that asbestos-induced PMs frequently harbor CDKN2A homozygous deletion and that the immunohistochemical loss of MTAP may represent a cheap and reliable surrogate marker for this molecular alteration, little is known about the molecular landscape and the reliability of MTAP immunohistochemistry in this peculiar subset of PM. The study herein presented investigated the prevalence of CDKN2A homozygous deletion and its concordance with MTAP immunohistochemical status on a cohort of 10 cases of FE-induced-PM from patients with environmental exposure to FE fibers, who were residents in the small town of Biancavilla (Sicily, Italy) or nearby areas. CDKN2A homozygous deletions were found in 3 out of 10 cases (30%) and all these cases showed concomitant cytoplasmic loss of MTAP with a concordance rate of 100%. Despite the relatively low number of cases included in our series, MTAP immunohistochemistry seemed to represent a reliable immunohistochemical surrogate marker of CDKNA homozygous deletion even in this subset of PMs.
    Keywords:  CDKN2A; Fluoroedenite; Homozygous deletion; MTAP; Pleural mesothelioma
    DOI:  https://doi.org/10.1016/j.prp.2024.155350
  3. Cancers (Basel). 2024 May 10. pii: 1817. [Epub ahead of print]16(10):
      Pleural mesothelioma (PM), linked to asbestos-induced inflammation, carries a poor prognosis. Therapy ranges from therapy limitation to aggressive multimodality treatment. Given the uncertainty about treatment benefits for patients, this study aimed to assess the role of Ki67 as a prognostic and predictive parameter in PM. Ki67 was measured in the specimens of 70 PM patients (17 female, 53 male) from two centers and correlated to overall survival (OS) and therapy outcome. The median OS was 16.1 months. The level of Ki67 expression was divided into low (≤15%) and high (>15%). A low value of Ki67 expression was associated with a longer OS (Ki67 ≤ 15%: 31.2 (95% CI 6.5-55.8) months vs. Ki67 > 15%: 11.1 (95% CI 7.7-14.6) months, p = 0.012). The 5-year survival represents 22% in the low Ki67 expression group, in contrast to 5% in the high Ki67 expression group. We found a significant interaction term of Ki67 with multimodality treatment (p = 0.031) translating to an OS of 48.1 months in the low expression Ki67 group compared to 24.3 months in the high Ki67 expression group when receiving surgery within multimodality therapy. Therefore, Ki67 stands out as a validated prognostic and, most importantly, novel predictive biomarker for treatment benefits, particularly regarding surgery within multimodality therapy.
    Keywords:  Ki67 index; cytoreductive surgery; inflammation; lung-sparing surgery; macroscopic complete resection; multimodality treatment; pleural mesothelioma; predictive biomarker; prognostic biomarker
    DOI:  https://doi.org/10.3390/cancers16101817
  4. Oncoscience. 2024 ;11 53-57
      Mesothelioma is an incurable cancer of the mesothelial lining often caused by exposure to asbestos. Asbestos-induced inflammation is a significant contributing factor in the development of mesothelioma, and genetic factors also play a role in the susceptibility to this rapidly progressive and treatment-resistant malignancy. Consequently, novel approaches are urgently needed to treat mesothelioma and prevent or reduce the overall incidence of this fatal disease. In this research perspective, we review the current state of chemoprevention and cancer interception progress in asbestos-induced mesothelioma. We discuss the different preclinical mouse models used for these investigations and the inflammatory factors that may be potential targets for mesothelioma prevention. Preliminary studies with naturally occurring phytochemicals and synthetic agents are reviewed. Results of previous clinical chemoprevention trials in populations exposed to asbestos and considerations regarding future trials are also presented.
    Keywords:  Bap1 mutations; asbestos; chemoprevention agents; inflammation; preclinical genetically engineered mouse models
    DOI:  https://doi.org/10.18632/oncoscience.605
  5. Cancers (Basel). 2024 May 17. pii: 1917. [Epub ahead of print]16(10):
      Pleural mesothelioma (PM) is a very aggressive malignancy with a poor prognosis. Most patients receive systemic treatment only; however, some patients may benefit from multimodality treatment. A precise staging of patients undergoing multimodal treatment is mandatory. We investigated the pattern of metastasis in a cohort of patients screened for multimodal treatment to define the extent of staging examinations. Additionally, we investigated the occurrence of metastasis during follow-up. We investigated a single-center experience of 545 patients newly diagnosed and/or treated with PM between the years 2010 and 2022. Patients who were treated naïvely and had a whole set of imaging of the brain were included and further analyzed. A total of 54% of all patients with cerebral imaging had an available 18FDG-PET CT scan. We also recorded metastasis during treatment follow-up. There were 110 patients who had a whole set of imaging (CT = 89% and MRI = 11%) of the brain, and 54% of all patients with cerebral imaging had an available 18FDG-PET CT scan. We identified four patients with cerebral metastasis at the time of first diagnosis, which means that 5.4% of the cohort had cerebral metastasis and 13.3% of all patients in the subgroup with complete data of 18FDG-PET CT had distant non-cerebral metastasis. During the longitudinal follow-up, we found 11 patients with newly diagnosed metastases after a median time of 1.6 years (range: 2 months to 3.3 years) after first diagnosis without metastases. Distant metastases are more frequent in mesothelioma patients than previously thought. This implies that extensive staging is needed for patients selected for multimodal treatment, including brain imaging and 18FDG-PET CT.
    Keywords:  MARS trial; PM; decortication; eP/D; epithelioid; epp; imaging; mesothelioma
    DOI:  https://doi.org/10.3390/cancers16101917
  6. Pathology. 2024 May 09. pii: S0031-3025(24)00127-2. [Epub ahead of print]
      The nomenclature and diagnostic criteria of well-differentiated papillary mesothelial tumour (WDPMT) have been changed in the 2021 World Health Organization (WHO) classification of thoracic tumours, and a new entity, mesothelioma in situ (MIS), introduced. Histologically these two entities may be similar. However, MIS is regarded as a precursor to invasive mesothelioma and requires demonstration of loss of BAP1 and/or MTAP/CDKN2A for diagnosis, whereas performance of these ancillary tests is desirable but not essential for a diagnosis of WDPMT, in which the significance of BAP1 and/or MTAP/CDKN2A loss is not well understood or well defined. Against this backdrop, we undertook an investigation of 21 cases of WDPMT, identified from our case files and diagnosed according to 2021 WHO criteria, to explore the relationship between histology and BAP1 and MTAP/CDKN2A expression with clinical features including asbestos exposure, focality of tumours and clinical outcome. There were 18 women and three men, with ages ranging from 23-77 years (median 62 years), in which six had a history of asbestos exposure, two had no exposure, and in 13 exposure history was unavailable. Of 20 peritoneal tumours and one pleural tumour, 13 were detected incidentally at the time of surgery for unrelated conditions and eight peritoneal tumours were multifocal at the time of diagnosis. BAP1 immunohistochemistry (IHC) was performed in all 21 tumours, with nine tumours showing BAP1 expression loss. MTAP/CDKN2A testing was performed in 14 tumours, comprising MTAP IHC in 12 and CDKN2A fluorescence in situ hybridisation (FISH) in two, with three tumours showing MTAP/CDKN2A expression loss. Two tumours with MTAP/CDKN2A loss also showed BAP1 expression loss. Four patients progressed to invasive mesothelioma, including one male with a pleural tumour and asbestos exposure, and three females with multifocal peritoneal tumours, two with asbestos exposure and one without exposure. BAP1 expression loss was seen in all tumours from the four patients who progressed to invasive mesothelioma, whilst two of these tumours showed retained MTAP IHC and two were not tested. There was one patient with a tumour with MTAP loss and retained BAP1 who died from unrelated causes 5 months after diagnosis. Eight patients received WDPMT-specific treatment in addition to the initial excision. Survival for all patients ranged from 4-218 months, with one patient dying of mesothelioma at 49 months. Based on our results in this series of 21 patients with WDPMT diagnosed according to 2021 WHO criteria, we propose that WDPMT with BAP1 expression loss may best be regarded as papillary MIS and that a history of asbestos exposure and the presence of multifocal tumours in patients diagnosed with WDPMT should prompt ancillary testing with BAP1 IHC. Further we propose that BAP1 IHC should be essential in the diagnosis of WDPMT, with the diagnosis restricted to those tumours which show retained BAP1 expression. However more studies in larger cohorts of patients are needed to explore the relationship between BAP1 expression and MTAP loss in WDPMT, which will help to define this entity and separate it more clearly from MIS and invasive mesothelioma.
    Keywords:  BAP1; CDKN2A; MTAP; Well-differentiated papillary mesothelial tumour; asbestos; mesothelioma in situ; well-differentiated papillary mesothelioma
    DOI:  https://doi.org/10.1016/j.pathol.2024.02.016