The role of ABCB1 polymorphism as a prognostic marker for primary central nervous system lymphoma

To investigate the possible role of functional single nucleotide polymorphism (SNP) in circadian genes as prognostic markers of primary central nervous system lymphoma (PCNSL). We conducted a prospective study using data from Huashan Hospital 2006-2015 and followed up 91 PCNSL patients until June 30, 2016. The survival of patients with different prognostic factors was compared by log-rank test. Univariate and multivariate analyses were performed by Cox regression. During a long-term follow-up (6-110 months), overall survival (OS) was 32 months (95% CI, 13.3-91.1) and progression-free survival (PFS) was 23 months (95% CI, 9.0-41.0) for the entire cohort. Age (P = 0.046, P = 0.001) and performance status (PS) score (P = 0.013, P = 0.003) showed differences in OS and PFS. ABCB1 rs1045642 variant showed significant difference in PFS between patients with CC genotype and those with CT/TT genotypes (P = 0.020). In multivariate analysis, age (HR = 2.3; 95% CI, 1.2-4.2, P = 0.008), PS (HR = 2.4; 95% CI, 1.3-4.4, P = 0.007), and ABCB1 rs1045642 (HR = 1.9; 95% CI, 1.0-3.3, P = 0.036) were the independent risk factors for PFS. In our results, the most important prognostic factors associated with higher risk of progression were ABCB1 rs1045642 CC genotype, PS > 2, and older age.