MYC overexpression correlates with MYC amplification or translocation, and is associated with poor prognosis in mantle cell lymphoma

Aims: We aimed to investigate MYC expression and chromosomal aberration in mantle cell lymphoma (MCL), and the clinical significance of these factors. Methods and results: Sixty-five patients with MCL, including 54 classic, nine blastoid and two pleomorphic variants, were enrolled. Expression of MYC, Ki67 and p53 was assessed by immunohistochemistry. MYC amplification or translocation was examined by fluorescence in-situ hybridization. MYC expression was higher in blastoid/pleomorphic MCL variants (mean, 19.0%) than in classic MCL (mean, 1.9%; P < 0.001). Expression of p53 and Ki67 was also significantly higher in these variants. MYC amplification was found in two of 53 cases tested, both of which were blastoid variants with high MYC expression (29.7% and 20.4%). MYC translocation was found in two of 52 cases tested, both of which were pleomorphic variants with remarkably high MYC expression (68.5% and 71.0%). High MYC or p53 expression was significantly associated with shortened overall survival and progression-free survival in univariable and multivariable analyses (all P < 0.05). Conclusions: MYC overexpression is a negative predictor of MCL patient outcomes. MYC gene amplification or translocation might be related to the pathogenesis of MCL, particularly in blastoid/pleomorphic variants.