JCHOR
Journal of Current Hematology & Oncology Research

The Journal of Current Hematology & Oncology Research regularly publishes internationally qualified research in hematology and oncology within the current scholarly knowledge.

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Original Article
SMARCA2 and SMARCA4 expression in epithelioid pleural mesothelioma: association with inflammatory microenvironment
Abstract
Aims: To investigate the frequency of SMARCA2 and SMARCA4 loss in epithelioid pleural mesothelioma (PM) and to evaluate their clinicopathological correlates, with particular attention to the inflammatory tumor microenvironment.
Methods: This retrospective study included 64 patients who underwent surgery for epithelioid PM between January 2007 and October 2019. Cases with biphasic histology, unavailable clinical data or tissue blocks, and early postoperative mortality were excluded. Clinicopathological parameters (age, sex, stage, histologic pattern, necrosis, inflammation) were reviewed. Immunohistochemistry for SMARCA2 and SMARCA4 was performed on tissue microarrays using anti-SMARCA4 (clone EPNCIR111A, 1:100) and anti-SMARCA2 (clone D9E8B, 1:100). Loss of expression was defined as complete absence of nuclear staining in tumor cells in the presence of an internal stromal positive control. Statistical analyses were conducted using R (version 3.5.1). Associations between categorical variables were assessed using chi-square or Fisher’s exact tests; continuous variables were compared using Student’s t-test or one-way ANOVA.
Results: The cohort comprised 51 men (79%) and 13 women (21%), with a mean age of 57.1 ± 12 years (range, 30–91). Fifty-three patients (82.8%) underwent decortication and 11 (17.2%) extrapleural pneumonectomy. Most tumors were stage I (n = 60, 94%), with 4 (6%) at stage II. Histologic patterns were tubulopapillary (n = 33, 50%), trabecular (n = 2, 3%), adenomatoid (n = 11, 18%), solid (n = 3, 6%), and micropapillary (n = 15, 23%). Inflammation was mild in 58 cases (91%) and severe in 6 (9%); necrosis was present in 8 cases (12.6%). Loss of SMARCA2 and SMARCA4 expression was detected in 4 patients each (6% for both markers). SMARCA2 loss was significantly associated with severe inflammation (p = 0.02), whereas no significant relationships were observed between SMARCA4 loss and age, sex, stage, histologic pattern, necrosis, or inflammation.
Conclusion: SMARCA2 and SMARCA4 loss are uncommon events in epithelioid PM. However, SMARCA2 deficiency is associated with a pronounced lymphocytic/inflammatory response, suggesting that SWI/SNF complex alterations may contribute to an immunogenic tumor microenvironment and could have potential biomarker or therapeutic relevance.

Keywords : Mesothelioma, pleural neoplasms, chromatin remodeling, SMARC A2, SMARC A4 , tumor microenvironment

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Article available in :
Volume 4, Issue 1, 2026
Page : 18-24
https://doi.org/10.51271/JCHOR-0076
Article Information
Received : 11 Kas 2025
Accepted : 19 Şub 2026
Published : 25 Şub 2026
Corresponding Author :

Neslihan Fener: Department of Pathology, Yedikule Chest Diseases and Thoracic Surgery Training and Research Hospital, İstanbul, Turkiye

[email protected]
Citation : Akanıl Fener N. SMARCA2 and SMARCA4 expression in epithelioid pleural mesothelioma: association with inflammatory microenvironment. J Curr Hematol Oncol Res. 2026;4(1):18-24.

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