[Clinicopathological features of de novo CD5-positive diffuse large B-cell lymphoma]

Objective: To investigate the relationship between the protein expression of C-MYC, bcl-2 and bcl-6 and the clinicopathological characteristics in patients with de novo CD5-positive diffuse large B cell lymphoma (CD5(+)DLBCL). Methods: Fifty seven cases of de novo CD5(+)DLBCL were collected at Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine from February 2013 to September 2018. The hematoxylin-eosin stained slides were reviewed, and immunohistochemical (IHC) staining and FISH were used to analyze the relationship between C-MYC, bcl-2, bcl-6 expression and the clinicopathologic characteristics of patients. Results: Among these 57 cases, 27 were male and 30 were female. The age of onset was 35-99 years old. The IHC expression rates of C-MYC, bcl-2 and bcl-6 were 50.9% (29/57), 84.2% (48/57), and 75.4% (43/57) respectively; and co-expression rate of C-MYC and bcl-2 proteins was 40.4 (23/57). There was no significant correlation between protein expression and patients' genders, clinical stage, the level of serum LDH,β2 microglobulin, IPI,B symptoms, bone marrow involvement and central nervous system recurrence (P>0.05). Univariate analysis showed that the median OS of C-MYC negative patients was significantly longer than C-MYC positive patients (P<0.05); and the median OS of patients without double expression was significantly longer than that of patients with positive expression (P<0.05), and bcl-6 positive patients had longer median OS than bcl-6 negative patients (P<0.05). There was no significant correlation between prognosis and bcl-2 protein expression (P>0.05) . Cox multivariate analysis showed C-MYC protein expression was an independent predictor of OS in de novo CD5(+)DLBCL (P<0.05). Conclusions: Bcl-2 protein expression has no effect on the prognosis in de novo CD5(+)DLBCL whereas bcl-6 expression is correlated with good prognosis. C-MYC protein expression could be used as an independent and effective index to predict the prognosis of patients with de novo CD5(+)DLBCL.However, the relationship between protein expression and gene rearrangement of C-MYC, bcl-2 and bcl-6 needs to be further explored.