BAP1 facilitates diagnostic objectivity, classification, and prognostication in malignant pleural mesothelioma

Area of Science:

• Oncology
• Pathology
• Biomarker Research

Background:

• BRCA-associated protein 1 (BAP1) is a potential biomarker for malignant pleural mesothelioma (MPM).
• The incidence and clinical significance of BAP1 loss in MPM are not well-defined.

Purpose of the Study:

• To investigate the diagnostic and prognostic value of BAP1 in MPM.
• To evaluate BAP1 expression for differentiating MPM subtypes and reactive mesothelial cells.

Main Methods:

• Construction of a tissue microarray from 111 MPM cases.
• BAP1 immunohistochemistry staining performed on the tissue microarray.
• Statistical analysis including Kaplan-Meier and multivariate analysis.

Main Results:

• BAP1 loss observed in 77% of epithelioid MPM, 49% of biphasic MPM, and retained in all sarcomatoid MPM and non-neoplastic mesothelial tissues.
• BAP1 immunohistochemistry demonstrated 61% sensitivity and 100% specificity for MPM diagnosis.
• BAP1 expression aided in distinguishing reactive mesothelial cells from malignant cells and supported histologic classification.
• BAP1 loss was associated with improved overall survival in Kaplan-Meier analysis, but not significant in multivariate analysis.

Conclusions:

• BAP1 loss is common in epithelioid MPM and correlates with improved survival.
• BAP1 serves as a valuable diagnostic and prognostic biomarker in MPM, aiding histologic classification.
• Patchy BAP1 staining in benign neoplasms necessitates caution when interpreting small biopsies.