[Clinical Features of Diffuse Large B-Cell Lymphoma Transformed from Follicular Lymphoma].

Objective: To analyze the clinical manifestations, pathological characteristics, therapeutic effect and prognosis of diffuse large B-cell lymphoma (DLBCL) transformed from follicular lymphoma (FL).

Methods: A total of 45 inpatients were eligible for criteria of histologic transformation from FL to DLBCL from January 2010 to January 2021, and their clinical characteristics, diagnosis, treatment and efficacy were collected and analyzed retrospectively.

Results: Among the 45 patients, transformation occurred at diagnosis in 27 cases, during " watch and wait " phase in 7 cases and after treatment of FL in 11 cases. The median age was 56 years old (ranged from 27 to 76 years), with 23 male and 22 female. The transformations were observed in 8 cases with low-grade and 37 cases with high-grade FL. Extranodal involvement was present in 26 cases, including bone marrow infiltration in 16 cases. There were 17 cases with anemia and 32 cases met the GELF criteria of high tumor burden. B symptoms were present in 12 cases. There were 38 cases with Ki-67≥50%. The germinal center B-cell-like (GCB) subtype of DLBCL was observed in 43 cases. Efficacy was evaluated in 45 cases. The OR, CR and PR rate were 80.0%, 60.0% and 20.0%, respectively. The OR,CR rate of patients received R-CHOP was higher than those of patients received other regimens (86.11% vs 55.55%, =0.063; 66.67% vs 33.33%, =0.126), but there was no significant statistical difference. The early transformation (at diagnosis) group showed the highest OR rate (85.18%) and CR rate (74.07%). The median follow-up time of all patients was 26 (4-120) months, and the median PFS (2-120 months) and median OS (5-120 months) had not yet reached. The 3-year PFS and OS were 55% and 70%, respectively. In univariate analysis, factors affecting PFS includ OR rate and POD24, and factors affecting OS includ IPI score, OR rate, POD24, B symptoms and anemia (<0.05).Multivariant analysis indicated that OR rate and POD24 were the independent prognostic factors for PFS (<0.05) and IPI score was an independent prognostic factor for OS (<0.05).

Conclusion: The OR and CR rates are higher in early transformation group of patients with DLBCL transformed from FL. Patients with anemia, B symptoms, POD24, and high-risk score have poor prognosis. IPI score is the independent prognosis factor for OS.