Association between LAPTM4B gene polymorphism and susceptibility to and prognosis of diffuse large B-cell lymphoma

Lysosomal protein transmembrane 4β (LAPTM4B) is an oncogene that is overexpressed in a number of various types of human cancer. There are two known alleles of LAPTM4B: LAPTM4B*1 and LAPTM4B*2. The present study assessed the association between LAPTM4B polymorphisms and the susceptibility to diffuse large B-cell lymphoma (DLBCL) and its prognosis. LAPTM4B genotypes were determined using polymerase chain reaction analysis in 164 DLBCL and 350 healthy control cases. The association between LAPTM4B polymorphisms and the risk of DLBCL was analyzed using unconditional logistic regression. Differences in patient survival were calculated using Kaplan-Meier analysis. The present study indicated no significant differences (P>0.05) in the frequency of LAPTM4B*2 alleles between DLBCL cases (26.5%) and controls (24.1%). The risk of DLBCL was slightly increased in cases with the LAPTM4B*1/2 genotype [odds ratio (OR)=1.160; 95% confidence interval (CI)=0.781-1.724] or the LAPTM4B*2/2 genotype (OR=1.446; 95% CI=0.648-3.227) compared with those with the LAPTM4B*1/1 genotype. There was no significant association between the presence of the LAPTM4B*2 allele and overall survival (OS) and disease-free survival (DFS) in patients with DLBCL (P=0.399 and 0.520, respectively). However, there was a tendency for patients with LAPTM4B*2 and International Prognostic Index (IPI) score 3-5 to have longer OS and DFS (P=0.126 and 0.109, respectively). These findings suggest that genetic polymorphisms of LAPTM4B is not a risk factor for the development of DLBCL, but the LAPTM4B*2 allele may a better prognostic indicator in patients with IPI score 3-5 in DLBCL.