Diversity of genetic alterations of primary central nervous system lymphoma in Hispanic versus non-Hispanic patients.

PURPOSE

Primary central nervous system lymphoma (PCNSL) is a rare type of non-Hodgkin lymphoma. Previous studies have identified MYD88, CD79b and PIM1 as the most common genetic mutations in PCNSL. The extent to which mutations vary by ethnicity is unknown. The purpose of this study was to describe differences in genetic mutations and survival by Hispanic ethnicity in PCNSL.

METHODS

30 patients with PCNSL were examined for mutations in 275 genes by DNA analysis and 1408 genes by RNA analysis utilizing next generation sequencing.

RESULTS

60% of patients were Hispanic. 125 different mutated genes were detected. The most commonly affected genes were: MYD88 (44%), CARD11 (21%), CD79b (17%), PIM1 (17%) and KMT2D (17%) . MYD88 mutation was less frequent in Hispanic patients (27% vs 66%, P=.02). More Hispanic patients had >3 mutated genes (89% vs 55 %. P=.03). Two-year progression-free survival (PFS) and overall survival (OS) in Hispanic vs. non-Hispanic patients (PFS 60% vs 27%, P=.09), (OS 60% vs 36%, P=.23). MYD88, CARD11, PIM1, and KMT2D were not associated with significant differences in OS or PFS. CD79b mutation correlated with superior 2-yr PFS (P=.04).

CONCLUSIONS

We identified highly recurrent genetic alterations in PCNSL. Our data suggest that heterogeneity in some mutations may be related to ethnicity. There was no statistically significant difference in 2-yr PFS and OS in our Hispanic patients. Studies on larger population may further help to describe differences in tumor biology, and outcomes in Hispanic patients.