The clinicopathological characteristics of C-MYC protein in angioimmunoblastic T-cell lymphoma.

AIM

To investigate the relationship between expression of C-MYC protein and clinicopathologic characteristics in angioimmunoblastic T-cell lymphoma (AITL), then discuss the prognosis.

METHODS

Patient samples were collected and made into tissue microarray for the same experimental condition. Pathomorphological features and immunohistochemistry of specific markers were used to determine the diagnosis of AITL. Epstein-Barr virus (EBV) infection was detected by EBV-encoded small RNA by in situ molecular hybridizations. B cells atypical hyperplasia was explored by the immunohistochemistry and gene rearrangement, C-MYC protein was expressed by the immunohistochemical staining and C-MYC gene abnormalities were detected by fluorescence in situ hybridization (FISH). 44 AITL patients were divided into two groups and the relation among C-MYC protein, EBV infection and B cells hyperplasia was observed. We followed up the overall survival rate (OS) and progression-free survival (PFS), and analyzed C-MYC protein, and the relationship between the prognosis of survival.

RESULTS

Among 44 AITL patients, 29 cases (65.9%) were C-MYC protein-positive, and 32 (32/44, 72.3%) were EBV-positive. The expression rate of C-MYC protein in the high-risk group ranked by international prognostic index (IPI) and stage III-IV were higher than that in the low-risk group and stage I-II (P<0.05). The expression rate of C-MYC protein was higher in B cells excessive proliferation group, including simple hyperplasia, atypical hyperplasia, monoclonal B cells hyperplasia, and the diffuse large B lymphoma than in the low-proliferation group (P<0.05). The expression rate of C-MYC protein in EBV-positive patients was indifferent compared with the negative group (P>0.05). C-MYC gene rearrangement was not found in any samples, while the multi-copies of the C-MYC gene were found in only one case. As followed, 5-year OS was significantly low, and there was no significant difference in OS between the C-MYC protein-positive and negative groups. PFS in the positive group was significantly lower than that of the negative group. The difference in response to treatment between the two groups was statistically significant (P<0.05).

CONCLUSION

We discussed the clinicopathologic characteristics and significance in AITLs, which predominantly express MYC-protein in <50% of cells, lacking C-MYC gene rearrangement. C-MYC protein-positive or negative expression was closely related to B cells excessive proliferation. C-MYC protein may be used as an indicator to judge the malignancy and to predict the prognosis of AITL.