ObjectiveTo explore the relapse-related genes and their clinicopathological connections of diffuse large B cell lymphoma (DLBCL).

MethodsTargeted panel sequencing was conducted on 32 eligible DLBCL samples; the patients were diagnosed, treated, and went into complete remission at the First Affiliated Hospital of Nanjing Medical University from January 2015 to December 2019, including 14 cases with recurrence (relapsed group) and 18 cases with long-term complete remission of over five years (remission group). Clinical and pathological data were further reviewed. Fisher′s exact test was employed to compare the differences in clinicopathological characteristics and mutation patterns between the two groups.

ResultsAmong the 32 patients, there were 18 males and 14 females, with a male to female ratio of 1.3∶1.0 and a median age of 53 (45.5, 67.0) years. In the relapsed group, PIM1 (11/14), KMT2D (7/14), PRDM1 (6/14), MYD88 (6/14), DTX1 (6/14) emerged as the most frequently mutated genes. In the remission group, while recurrent PIM1, KMT2D and MYD88 mutations were also observed, the TP53 gene exhibited the highest mutation frequency (6/18). Compared to the remission group, relapsed group showed elevated mutation frequencies of PIM1 ( P=0.013) and FAT4 ( P=0.010), alongside a reduced incidence of TP53 mutations. In all 32 patients, DLBCL with CD79B, CCND3, DTX1, KMT2D and PRDM1 mutations demonstrated a propensity towards advanced clinicopathologic stage.

ConclusionsRelapsed DLBCL has distinctive clinicopathological and genetic features. PIM1 and FAT4 may be served as potential biomarkers for screening relapsed DLBCL-NOS and as targets for novel therapeutic strategies.