MYC and BCL2 overexpression is associated with a higher class of Memorial Sloan-Kettering Cancer Center prognostic model and poor clinical outcome in primary diffuse large B-cell lymphoma of the central nervous system

摘要

Background Primary diffuse large B-cell lymphoma of the central nervous system (PCNS-DLBCL) is a distinct clinicopathological entity with a poor prognosis. Concurrent MYC and BCL2 overexpression predicts inferior prognosis in systemic DLBCLs. However, the prognostic significance of MYC and BCL2 in PCNS-DLBCL remains elusive. Methods Immunohistochemistry (IHC) of MYC, BCL2 and BCL6 was performed on tumor samples from 114 patients with PCNS-DLBCL. IHC score was assigned based on the proportion of immunostained cells. Results MYC, BCL2, and BCL6 IHC scores were 18.16?±?19.58, 58.86?±?35.07, and 39.39?±?37.66?% (mean?±?SD), respectively. Twenty-one cases (18.1?%) were designated as MYC-positive with a cutoff score of 40. BCL2 positivity was found in 87 cases (75.0?%) using a cutoff score of 30. MSKCC (Memorial Sloan-Kettering Cancer Center prognostic model) class 2 and 3 had higher rates of MYC and/or BCL2 positivity (MYC, P =?0.012; BCL2, P =?0.008; dual-positive, P =?0.022). Poor KPS (Karnofsky Performance Status score 60?years) showed poorer overall survival (OS) ( P =?0.020). MYC positivity was associated with poor PFS ( P =?0.027), while patients with BCL2 positivity exhibited a shorter OS ( P =?0.010). Concomitant MYC and BCL2 positivity was related to poor PFS ( P =?0.041), while the lack of both MYC and BCL2 expression was related to prolonged OS ( P =?0.014). MYC and BCL2 expression had no independent prognostic implication by multivariate analysis in overall patients with PCNS-DLBCL. However, among patients treated with combined high-dose methotrexate, vincristine and procarbazine and radiotherapy, dual MYC and BCL2 overexpression (a cutoff score of 60) was an independent poor prognostic indicator ( P =?0.010). Conclusions Evaluation of MYC and BCL2 expression may be helpful for the determination of PCNS-DLBCL prognosis.