Utility of a Reverse Phase Protein Array to Evaluate Multiple Biomarkers in Diffuse Large B‐Cell Lymphoma

PURPOSE: Diffuse large B‐cell lymphoma (DLBCL), the most common non‐Hodgkin lymphoma, is a heterogeneous lymphoma with different clinical manifestations and molecular alterations, and several markers are currently being measured routinely for its diagnosis, subtyping, or prognostication by immunohistochemistry (IHC). Here, the utility of a reverse‐phase‐protein‐array (RPPA) as a novel supportive tool to measure multiple biomarkers for DLBCL diagnosis is validated. EXPERIMENTAL DESIGN: The expression of seven markers (CD5, CD10, BCL2, BCL6, MUM1, Ki‐67, and C‐MYC) is analyzed by RPPA and IHC using 37 DLBCL tissues, and the correlation between the two methods is determined. To normalize tumor content ratio in the tissues, the raw RPPA values of each marker are adjusted by that of CD20 or PAX‐5. RESULTS: The CD20‐adjusted data for CD5, MUM1, BCL2, Ki‐67, and C‐MYC has better correlation with IHC results than PAX‐5‐adjusted data. Receiver operating characteristic (ROC) analysis reveals that CD5, MUM1, BCL2, and C‐MYC exhibit a better sensitivity and specificity >0.750. Furthermore, the CD20‐adjusted C‐MYC value strongly correlates with that of IHC, and has a particularly high specificity (0.882). CONCLUSIONS AND CLINICAL RELEVANCE: Although further investigation using a large number of DLBCL specimens needs to be conducted, these results suggest that RPPA could be applicable as a supportive tool for determining lymphoma prognosis.