[Prognostic analysis of BCL-2/MYC double- hit in diffuse large B-cell lymphoma]

[The incidence of high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements in diffuse large B-cell lymphoma]

Objective: To investigate the incidence of high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangement in Chinese diffuse large B-cell lymphoma (DLBCL) . Methods: From January 2013 to August 2020, 922 DLBCL cases were collected. C-MYC and BCL2 protein expression levels were analyzed by immunohistochemistry staining. Fluorescence in situ hybridization was used to detect the structural abnormalities of MYC, BCL2, and BCL6, including gene breaks and copy number changes. Results: MYC and BCL2 and/or BCL6 gene breaks were found in 29 out of 922 DLBCL cases (3.15%) , including 25 cases of double-hit lymphoma (DHL; 14 cases involving MYC and BCL2 rearrangements and 11 cases involving MYC and BCL6 rearrangements) and four cases involving MYC, BCL2, and BCL6 rearrangements, referring to triple-hit lymphoma. According to the threshold of C-MYC ≥40% and BCL2 ≥50%, 541 cases (58.68%) overexpressed C-MYC and BCL2 proteins, including 22 DHL cases. Moreover, according to the threshold of C-MYC ≥70% and BCL2 ≥50%, 52 cases (5.64%) overexpressed C-MYC and BCL2 proteins, including nine DHL cases. The P53 protein expression was detected by immunohistochemistry staining. The mutant P53 expression pattern was shown in 101 out of 709 cases (14.25%) , whereas 13 cases (1.83%) were negative, likely indicating P53 gene fragment deletion. Conclusion: The incidence of high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements was low in DLBCLs, and no significant correlation between gene abnormality and protein overexpression was shown. The correct diagnosis of DHL depends on molecular genetic detection.

[Prognostic significance of proteins expression by immunohistochemical method in diffuse large B cell lymphoma]

Objective: To analyze the prognostic significance of TP53, Bcl-2, Bcl-6, Myc proteins expression by immunohistochemical method (IHC) in diffuse large B cell Lymphoma (DLBCL) . Methods: Clinical and pathologic data of 223 patients with DLBCL hospitalized in Zhejiang First Hospital from March 2009 to June 2015 were retrospectively analyzed. Results: The 223 cases, a median age of 56 years old with a male predominance, had shown a 39.0% of TP53 positive expression, 38.6% of Myc, 69.1% of Bcl-2, 56.5% of Bcl-6, and 22.7% of Myc/Bcl-2 double expression. According to Hans' classification, 27.4% were GCB and 72.6% were non-GCB. With a median follow-up of 38 (2-97) months, the 3 and 5 years survival rates were 70% and 66% , respectively. By multivariate analysis, TP53 over-expression and Myc/Bcl-2 double expression were independently associated with poor outcomes. 3-year and 5-year overall survival were 59% and 57% for patients with TP53 positive, 77% and 71% for patients with TP53 negative expression. Patients with non-GCB subtype receiving chemotherapy combined with rituximab had a higher OS than those without rituximab. But rituximab did not improve the prognosis of patients with TP53 positive. Conclusion: Myc/Bcl-2 double expression and TP53 over-expression are poor prognosis for DLBCL patients. Patients with Myc/Bcl-2 double expression have shorter OS. Patients with non-GCB subtype who received chemotherapy combined with rituximab have a better OS than those without rituximab. But rituximab does not improve the prognosis of patients with TP53 positive.