A Preliminary Study On Bmi-1 Expression In Extranodal Nk/t-cell Lymphoma And Its Clinical Significance

Background and Objiective: NKTCL is a rarely kind of NHL which typically affects the nasal cavity.Clinically, the condition of NKTCL patients is often deteriorating rapidly and have poor prognosis. Part of the stageⅠ,ⅡNKTCL patients recurrening in short-term even after radical radiotherapy, also some of stageⅢ,Ⅳpatients'condition progressing Rapidly ,even after forcefully comprehensive treatment.Which indicates that it is a kind of heterogeneous disease, different patients have different prognosis。However there was no consistent conclusion in the NHL'commonly used prognostic indicators such as:临床stage, LDH, B symptoms。Therefore, it is an inevitable trend to find some new prognostic indicators for NKTCL. Recently, many biomarkers for identifying NHL have appeared to be hotspots of research, including Bmi-1. Bmi-1 is a PcG, firstly found by Dutch Cancer Center in mouse lymphoma cells in 1991. Recently, it is confirmed that the expressions of Bmi-1 are abnormal in many kinds of tumors such as diffuse large B cell lymphoma, playing an important role in these tumors'occurrence and development. We examined whether Bmi-1 expression in NKTCL correlates with patients'Prognosis. Methods: We selected 29 paraffin blocks with final diagnosis pathologically NKTCL of of Guangzhou Medical College, Sun Yet-Sen University cancer center and Guangzhou First Municipal People's hospital. Clinical data, including sex, age, clnical staging, LDH before treatment and so on are recorded. Bmi-1 expression was examined immunohistochemically. To analyze the relationship between prognosis and Bmi-1.Results: In 29 primary tumor tissues, 11(37.9%) patients showed Bmi-1 low expression,14(37.9%) patients showed Bmi-1 medium expression, while 4 (13.8%) showed strong. There was no Bmi-1 expression in the adjacent tissues. The difference mentioned above shows significance when tested by chi-square test(P <0.05). Also we found the Bmi-1 expression levels have no correlations with patients'sex, age, LDH , primary site ,B symptoms, KPS scores, IPI scores and Vascular Center of pathology(P >0.05), except for clinical stage(P <0.05).The strong expression patients was more likely sharing an advanced stage. In survival analysis, the NKTCL patients who presented with Bmi-1 strong expression had longer OS after treatment. The median survival and the average survival in Low expression patients were 21.33 months and 29.94 months, while 31.67 months and 34.66 months separately in strong expression patients. Avnalysis by Kaplan-Meier,the Bmi-1 and patients'sex, age, LDH , primary site ,B symptoms, KPS scores,IPI scores and Vascular Center of pathology expression levels have no correlations with patients'OS(P >0.05)(Bmi-1:P=0.859)。Conclusion:The Bmi-1 expression levels have correlations with patients'clinical stage. The strong expression patients is more likely sharing an advanced stage. There is a trend that Bmi-1 strong expression patients have longer Overall Survival (OS).