bims-mesote Biomed News
on Mesothelioma
Issue of 2021‒05‒30
six papers selected by
Laura Mannarino
Humanitas Research

  1. Cureus. 2021 Apr 21. 13(4): e14605
      Introduction Pleural mesothelioma constitutes about 80% of all mesotheliomas. The peak incidence of malignant mesothelioma estimated using the cancer registries was in early 1990 to 2000 in the United States. The disease is primarily associated with asbestos exposure. The latency period between asbestos exposure and the development of malignant pleural mesothelioma (MPM) can range anywhere from 15 to 60 years. Asbestos exposure was peaked during the industrial revolution and World War II due to military and shipyard exposures. It is often difficult for the pathologist to distinguish different histological subtypes; due to the disease's rarity and the inadequate tissue sample obtained. There is no available data on the difference in epidemiology of different subtypes of MPM. Surveillance Epidemiology and End Results (SEER), cancer incidence data include population-based registries covering approximately 34.6% of the U.S. population. Here in our study, we analyze malignant pleural mesothelioma epidemiology in the United States, emphasizing different histological subtypes. Methods SEER data from 2000 to 2016 was used in our study. The primary site of cancer is selected as pleura, and malignant behavior only is selected as the filter. Data were analyzed using the SEER stat program. Overall epidemiology of MPM and epidemiology of epithelioid, fibrous, and biphasic histological subtypes were analyzed separately. We used annual percentage change (APC) to evaluate the trend in the epidemiology of MPM. Results summary A total of 11,857 cases of MPM were included in the primary cohort from the SEER 18 registry from 2000 to 2016. The total prevalence of MPM was highest in 2009 and was lowest in 2016. The APC in MPM incidence during this period is -2.0. After removing 5,989 cases with non-specified histology during the same period, the APC for each histological type is -0.7 for fibrous type, 1.8 for epithelioid type, and 2.9 for biphasic type. Out of 17 regional registries included in the study, the greatest statistically significant change in APC was seen in the Hawaiian registry -4.1. In contrast, the lowest statistically significant difference was seen in Seattle (Puget Sound) registry -1.7. The APC in the incidence of MPM among males during the study period was -2.4 while that of females was -0.9. The Iowa registry showed a statistically significant increase in APC of the epithelioid malignant mesothelioma with a statistically insignificant reduction in the overall MPM APC. Conclusion The overall incidence of MPM in the United States is declining, while the data showed an increase in the incidence of epithelioid and biphasic histological subtypes. The authors believe that these conflicting results can be attributed to improved histological diagnosis and improved biopsy techniques.
    Keywords:  asbestos; malignant pleural mesothelioma; mesothelioma; national cancer database and seer analyses
  2. Cytopathology. 2021 May 25.
      OBJECTIVE: To assess the utility of BRCA-1 associated protein 1 (BAP1) immunohistochemistry (IHC) for the diagnosis of malignant pleural mesothelioma (MPM) in pleural fluid samples with atypical cytology.METHODS: Pleural fluid samples received between January 2015 and March 2018 at a tertiary referral centre with a diagnosis of atypical mesothelial proliferation (diagnostic categories: 'atypical' and 'suspicious') were identified. Results of 'routine' IHC testing were recorded for each case. BAP1 by IHC was performed and a final diagnosis sought from subsequent pathology specimens, medical records or consensus clinical diagnosis.
    RESULTS: 50 cases were identified, 41 cases were reported as atypical and 9 suspicious. Seven (14%) demonstrated loss of BAP1 staining, 40 retained BAP1 staining, 1 had heterogeneous staining and 2 had insufficient cells for analysis. All seven cases with BAP1 loss were diagnosed with MPM on follow up. Of those with retained BAP1, 52.5% (21) were subsequently diagnosed with MPM, while 40% (16) had non-MPM diagnoses after a median follow up of 24 months. Three cases were not further investigated based on patient and clinician decision. The case with heterogeneous staining was diagnosed as mesothelioma by clinical consensus.
    CONCLUSIONS: BAP1 IHC loss is highly specific for malignancy and has value as a rule in test. Even in a tertiary centre with clinical interest in the cytological diagnosis of MPM this investigation can increase diagnostic accuracy beyond routine IHC studies. Cytological criteria remain valuable as retained BAP1 in an atypical or suspicious mesothelial proliferation cannot exclude malignancy.
    Keywords:  BAP1 immunohistochemistry; Malignant mesothelioma; cytology; pleural effusion
  3. Am J Ind Med. 2021 May 25.
      Malignant mesothelioma (MM) is one of the most aggressive cancers with the poorest of outcomes. There is no doubt that mesothelioma in males is related to asbestos exposure, but some authors suggest that most of the cases diagnosed in females are "idiopathic." In our assessment of the science, the "low risk" of mesothelioma in females is because of the nonsystematic recording of exposure histories among females. Indeed, asbestos exposure is mentioned in only some of the studies that include females. We estimate the risk of MM among females to be close to that in males. The absence of detailed exposure histories should be rectified in future studies involving ​women. As a matter of social justice, the ongoing failure to recognize asbestos as the cause of a majority of cases of MM in females does them, and their kin, a profound disservice.
    Keywords:  asbestos; etiology; exposure history; mesothelioma; women
  4. Gen Thorac Cardiovasc Surg. 2021 May 24.
      OBJECTIVE: Pleurectomy/decortication has been preferably employed as a curative-intent surgery for malignant pleural mesothelioma. However, visceral pleurectomy during pleurectomy/decortication provides technical challenges. For visceral pleurectomy, pleural incisions are commonly made to create a dissection plane between the visceral pleura and the lung parenchyma, which may cause tumor dissemination and may not allow en bloc complete resection of the entire pleura. To overcome such potential disadvantages, we have developed a novel surgical technique without any pleural incision (non-incisional pleurectomy/decortication) to achieve en bloc removal of the entire pleura.METHODS: A total of 36 consecutive patients who underwent non-incisional pleurectomy/decortication for malignant pleural mesothelioma from January 2017 through December 2020 in our institute were retrospectively reviewed to assess the feasibility.
    RESULTS: Macroscopic complete resection was achieved in 31 patients (86.1%) with non-incisional pleurectomy/decortication. In the majority of patients (n = 29), en bloc complete resection of the entire pleura was achieved (without pleural laceration in 10 and with some pleural laceration in 19 patients). The total operation time and the duration of visceral pleurectomy were significantly shorter as compared with those for conventional pleurectomy/decortication (median, 350 versus 506 min [P = 0.011], and 43 versus 97 min [P < 0.001], respectively). Among 36 patients who underwent non-incisional pleurectomy/decortication, postoperative complications developed in 13 patients (36.1%), and one patient died on the postoperative day 95 caused by aggressive tumor progression of residual tumor.
    CONCLUSIONS: Non-incisional pleurectomy/decortication is a fast and feasible technique to achieve en bloc macroscopic complete resection for malignant pleural mesothelioma.
    Keywords:  Decortication; Mesothelioma; Pleurectomy; Surgery
  5. Cell Death Discov. 2021 May 28. 7(1): 122
      Malignant pleural mesothelioma (MPM) is an aggressive cancer with treatment limited to Cisplatin and Pemetrexed chemotherapy. Recently, we showed that drugs targeting the BCL-2-regulated apoptosis pathway could kill MPM cell lines in vitro, and control tumor growth in vivo. These studies showed BCL-XL was the dominant pro-survival BCL-2 family member correlating with its high-level expression in cells and patient tumor samples. In this study we show another inhibitor, AZD4320 that targets BCL-XL (and BCL-2), can also potently kill MPM tumor cells in vitro (EC50 values in the 200 nM range) and this effect is enhanced by co-inhibition of MCL-1 using AZD5991. Moreover, we show that a novel nanoparticle, AZD0466, where AZD4320 is chemically conjugated to a PEGylated poly-lysine dendrimer, was as effective as standard-of-care chemotherapy, Cisplatin, at inhibiting tumor growth in mouse xenograft studies, and this effect was enhanced when both drugs were combined. Critically, the degree of thrombocytopenia, an on-target toxicity associated with BCL-XL inhibition, was significantly reduced throughout the treatment period compared to other BCL-XL-targeting BH3-mimetics. These pre-clinical findings provide a rationale for the future clinical evaluation for novel BH3-mimetic formulations in MPM, and indeed, other solid tumor types dependent on BCL-XL.
  6. Am J Surg Pathol. 2021 May 27.
      ATF1, CREB1, and CREM, which encode the CREB family of transcription factors, are fused with EWSR1 or FUS in human neoplasms, such as angiomatoid fibrous histiocytoma. EWSR1/FUS-CREB fusions have recently been reported in a group of malignant epithelioid tumors with a predilection to the peritoneal cavity and frequent cytokeratin expression. Here, we studied 8 cytokeratin-positive abdominal malignancies with these fusions for further characterization. The tumors affected males (15 to 76 y old) and presented as intra-abdominal masses with concurrent or subsequent peritoneal dissemination, ascites, and/or metastases to the liver or lymph nodes. Four patients died of the disease within 18 to 140 months. Cases 1 to 5 showed multinodular growth of monomorphic epithelioid cells with focal serous cysts. Lymphoplasmacytic infiltration was prominent and was associated with systemic inflammatory symptoms. Two patients suffered from membranous nephropathy with nephrosis. The tumors displayed partly overlapping phenotypes with malignant mesothelioma, including diffuse strong expression of AE1/AE3 and WT1 and membranous positivity of sialylated HEG1, although calretinin was negative. Case 6 showed similar histology to cases 1 to 5, but expressed smooth muscle actin diffusely, lacked WT1 and HEG1, and harbored prominent pseudoangiomatous spaces. Cases 7 and 8 displayed dense growth of small oval to short spindle cells, with occasional molding and minor swirling, superficially resembling small cell carcinoma. Lymphoplasmacytic infiltration was not observed. The tumors were positive for AE1/AE3 and CD34 (focal), whereas calretinin, WT1, and HEG1 were negative. The detected fusions were FUS-CREM (n=4), EWSR1-ATF1 (n=2), EWSR1-CREB1 (n=1), and EWSR1-CREM (n=1). We confirmed the prior observation that these tumors do not fit perfectly with known entities and provided additional novel clinicopathologic information. The tumors require wider recognition because of more aggressive behavior than angiomatoid fibrous histiocytoma despite similar genetics, and potential misdiagnosis as unrelated diseases, such as neuroendocrine neoplasms.