Abstract:
The role of MYC dysregulation has been studied extensively in B cell lymphomas, but little is known about its significance in T cell lymphomas. This study, for the first time in the literature, assessed the clinicopathologic and prognostic significance of MYC expression in ALK+ anaplastic large cell lymphoma (ALCL) cases. Using > 50% as the cutoff value for positive MYC expression by immunohistochemistry, 17 of 46 (37%) cases were MYC+. Patients with MYC+ tumors were older (median age, 39 versus 29 years, p = 0.04) and more often showed a common morphologic pattern (100% versus 69%, p = 0.02), when compared with those with MYC-negative tumors. By fluorescence in situ hybridization (FISH) analysis, 9 of 31 (29%) cases showed increased MYC copy number and 1 of 31 (3%) case had a MYC rearrangement, and the remaining 21 (68%) cases showed no MYC aberrations. Among the cases with increased MYC copy number, 5 of 8 (62%) cases showed MYC copy gain and/or amplification and 3 of 8 (38%) had polysomy 8. MYC expression was associated with increased MYC copy number (p = 0.01). MYC expression, but not increased MYC copy number, correlated with shorter overall survival (p = 0.03). In conclusion, MYC expression identified a distinct group of ALK+ ALCL patients with more aggressive behavior and shorter overall survival. Our data suggest that MYC expression is an adverse prognostic factor and may be useful in stratifying or predicting the prognosis of patients with ALK+ ALCL
