소포성 림프종의 임상적 및 병리학적 특징과 FISH 분석을 통한 세포유전학 특징의 분석에 대한 연구

Abstract

Background Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma in western countries, but is relatively rare in Asia. Only a few studies have described its genetic aberration and clinicopathologic significance in Asia. Methods We retrospectively analyzed annual frequency of FL and clinicopathological features of 296 cases of FL between 1991 and 2017. We applied fluorescence in situ hybridization (FISH) analysis to investigate prognostic significance of BCL2, BCL6, and MYC translocation or copy number aberration (CNA) in 129 FL cases between 2013 and 2017 in Asan Medical Center in Seoul. Results The annual frequency of FL (patients with FL/total inpatients) has increased from 0.01% in 1991 to 0.04% in 2017. Patients predominantly belonged to low risk group of FLIPI and low histologic grade. 7.2% of patients showed diffuse large B-cell lymphoma (DLBCL) transformation. Majority of patients (63.7%) was treated with chemotherapy (25.5%, R-CHOP; 21.7%, R-CVP). Of the histologic parameters, higher grade was associated with less frequent expression of BCL6 or CD10 (P<0.05 and P<0.001, respectively). Ki-67 index showed significant correlation with grade (p<0.001) and growth pattern (p<0.001). High risk group of FLIPI and FL grade 3B showed worse OS (P<0.001 and P=0.002, respectively). By FISH analysis, higher grade showed lower frequency of BCL2 translocation (P < 0.001). By univariate analysis, BCL6 CNA showed correlation with worse OS and PFS, while BCL2 CNA and MYC CNA did not (HR, 11.884; 95% CI, 1.170 – 120.756, P = 0.036).

Conclusions This study shows recent increase in incidence, clinicopathologic and cytogenetic characteristics of FL in Korea. Of the cytogenetic features, FL with CNA of BCL6 was significantly associated with poor survival outcome. This study is the first report to evaluate prognostic significance in clinicopathologic and cytogenetic factors including CNA of BCL2, BCL6 and MYC in Korea population.