Clinical features, gene mutation profile and prognosis analysis of diffuse large B-cell lymphoma complicated with follicular lymphoma / 白血病·淋巴瘤

ABSTRACT

Objective:To investigate the clinicopathologic characteristics, gene mutation profile and prognostic influencing factors of diffuse large B-cell lymphoma (DLBCL) complicated with follicular lymphoma (FL) (DLBCL/FL).Methods:The clinicopathological data of 50 DLBCL/FL patients admitted to Rui Jin Hospital Affiliated of Shanghai Jiao Tong University School of Medicine from February 2018 to November 2021 were retrospectively analyzed. Targeted sequencing was performed to assess the mutation profile of 55 lymphoma-related genes. The clinicopathological characteristics were summarized to evaluate the short-term therapeutic efficacy of all patients. Kaplan-Meier method was used to analyze the overall survival (OS) and progression-free survival (PFS) of patients. Cox regression risk models were used to assess the factors affecting the OS and PFS.Results:Among 50 DLBCL/FL patients, 23 cases (46%) were male, 22 cases (44%) had an international prognosis index (IPI) score ≥ 2 points, 16 cases (32%) were double-expression lymphoma (DEL) and 4 cases (8%) were double-hit lymphoma (DHL). The complete response (CR) and overall response rates were 68% (34/50) and 78% (39/50), respectively after the first-line therapy. The median follow-up time was 23.3 months (5.1-50.9 months). The 2-year OS rate was 82.1% and 2-year PFS rate was 67.1%; and the median OS and PFS were not reached. Targeted sequencing results showed that the mutation frequencies of KMT2D, MYD88, TP53, BTG2, DTX1, EZH2, CD70, CREBBP, DUSP2, HIST1H1C, HIST1H1E and PRDM1 genes in this cohort were more than 15%. Multivariate Cox regression analysis showed that male ( HR = 4.264, 95% CI 1.144-15.896, P = 0.031) and IPI score ≥ 2 points ( HR = 6.800, 95% CI 1.771-37.741, P = 0.007) were independent risk factors of PFS in newly diagnosed DLBCL/FL patients, and TP53 mutation ( HR = 4.992, 95% CI 1.027-24.258, P = 0.046) was an risk influencing factor of OS. Conclusions:The proportion of male and female DLBCL/FL patients is similar, with a small proportion of DHL. Mutations of KMT2D, MYD88 and TP53 genes are commonly found in DLBCL/FL patients. Generally, DLBCL/FL patients can have a high overall response and good prognosis. Male and IPI score ≥ 2 points are the independent risk factors of PFS, and TP53 mutation is an independent risk factor of OS in DLBCL/FL patients.