Clinical Significance Of Expression Of C-myc And Bcl-2 Proteins In The Primary Central Nervous System Lymphoma

Objective: To analyze the clinical and pathological features of the primary central nervous system lymphoma(PCNSL)and the clinical significance of expression of C-myc and Bcl-2 proteins in PCNSL patients.Method: The clinicopathological data of 67 patients diagnosed as PCNSL in Fujian Medical University Union Hospital,from May 2007 to April 2017,were collected,which included: clinical features,laboratory examination,C-myc and Bcl-2 protein expression and long-term survival time,etc.Clinical indicators of age,gender,LDH,cerebrospinal fluid protein,lesion site,ki-67,c-myc,bcl-2,and different treatment protocols were used for the survival assessment of univariate analysis through kaplan-meier method and log-rank test and multivariate analysis by Cox proportional risk regression model.Results: Among the 67 cases of PCNSL in the study,39 were males(58.2%)and 28 females(41.8%),and the ratio of males to females was 1.4:1.23 cases(34.3%)were above 60 years old and 44(65.7%)younger than the age of 60,and the median age was 53.The symptoms were dizziness,headache,nausea,vomiting,weakness of one limb and other symptoms,and some patients had no obvious symptoms.In this study,the morphology of PCNSL patients was mainly focused on the centroblastic type,and the pathological type was diffuse large B-cell lymphoma(DLBCL).According to Hans model classification,origin of germinal center B cell subtype(germinal center B-cell,GCB)accounted for 34.3%(23/67),the origin of non-germinal center B cell subtype(non-germinal center B-cell-like,non-GCB)accounted for 61.2%(41/67),including three of the patients were unable to be subtyped due to lack of detailed pathological results.There were 48 patients with pathological bcl-2 immunohistochemical(IHC)staining,of which 40 cases of patients had c-myc immunohistochemical(IHC)staining.There were 37 patients with bcl-2 protein expression positive(cutoff score of 30%),23 patients had high levels of expression of bcl-2 protein(cutoff score of 85%),11 cases of c-myc protein expression positive(cutoff score of 40%),8 cases of C-myc(?40%)and Bcl-2(?30%)co-expressed.The median survival time was 14 months,and the cumulative overall survival(OS)rate at 1,2 and 3 years was 59.7%,52.9% and 41.6% respectively.Univariate analysis showed that patients' gender,lesion location,LDH,immune-phenotype,bcl-6 protein expression,and Ki-67(greater than 90%)had no significant prognostic significance(P>0.05).The prognosis was better(P<0.05)in patients younger than 60 years old,with ECOG score less than 2 and bcl-2 protein expression less than 85%.The prognosis of patients with methotrexate-based protocol treatment is better than that of surgery alone(P=0.046).Multivariate analysis showed that the high expression of C-myc protein(more than 40%)was independent prognostic factor(P=0.032).Conclusions: PCNSL patients are mainly of DLBCL type and their overall prognosis is poorer than that of non-specific type DLBCL.Age,ECOG score,bcl-2 expression rate,different treatment methods are associated with overall survival.Methotrexate monotherapy or combined chemotherapy regimen based on high dose of methotrexate had better outcome.The high expression of c-myc protein(more than 40%)is independent prognostic factor.