Rituximab response in follicular lymphoma is associated with the rs20575 polymorphism in TRAILR1 extrinsic apoptosis trigger.

OBJECTIVE: Rituximab in combination with chemotherapy has been proven to increase progression-free and overall survival in follicular lymphoma (FL), but there is considerable interindividual variability in the response. Extrinsic pathway apoptosis triggered by death receptors seems to be involved in the mechanism of action of monoclonal antibodies. This study aimed to assess the association between TRAILR1/TRAIL polymorphisms (rs20575, rs20576, rs2230229, rs12488654) and rituximab response and the relationship with FASL rs763110, previously found to be associated with rituximab response. PATIENTS AND METHODS: Polymorphisms were determined in a study cohort of 125 FL patients treated with rituximab as first-line treatment and correlated with response, which was scored according to the International Working Group Consensus Revised as complete response, partial response, stable disease, and progressive disease. RESULTS: No significant association with response was found for rs20576, rs2230229, and rs12488654 polymorphisms. In contrast, rs20575 GC/GG carriers were more partial/nonresponders (88.2%) than complete responders (72.5%), showing a trend toward statistical significance (P=0.064). In a multivariable setting, we found that female sex [odds ratio=0.355, 95% confidence interval (CI): 0.137-0.922, P=0.033] and the TRAILR1 rs20575 CC genotype (odds ratio=0.162, 95% CI: 0.035-0.757, P=0.021) were independent positive predictive factors of complete clinical response to rituximab, constructing a parsimonious model with good calibration [χ of 5.719 (d.f.=6, P=0.455)] and discrimination (C-statistic=0.739, 95% CI: 0.636-0.842). CONCLUSION: After studying the pharmacogenetic role of TRAILR1/TRAIL polymorphisms in rituximab-treated FL patients, we found that the rs20575 CC genotype is an independent predictive factor of better rituximab response, indicating the possible involvement of death receptors in anti-CD20 mechanisms of action.

Association of polymorphisms in TRAIL1 and TRAILR1 genes with susceptibility to lymphomas.

The TRAILR1/TRAIL system is implicated in the induction of the extrinsic apoptotic pathway and constitutes an emerging target in cancer therapeutics. The objective of this study is to assess lymphoma risk associated with certain polymorphisms in TRAILR1 and TRAIL1 genes. DNA was extracted from 381 subjects (190 lymphoma cases and 191 matched controls) and genotyped for polymorphisms rs20576, rs2230229 and rs20575 in TRAILR1 and rs12488654 in TRAIL gene. In contrast to TRAILR1 polymorphisms, the genotype distribution of rs12488654 in TRAIL gene was different between cases and controls, A allele carriers (CA/AA) being much more common in the cases with different lymphoma types (follicular, 45 %; diffuse large B cell, 45.2 % and Hodgkin lymphomas, 40 %) than in controls (15.7 %) (odds ratio (OR), 3.5; CI, 2.1­5.9; p<0.001; OR, 3.5; CI, 1.6­7.9; p=0.001; OR, 2.9; CI, 1.1­7.5; p=0.027, respectively). This effect was consistently independent of the association with the TRAILR1 polymorphisms studied, as demonstrated by linkage disequilibrium and haplotype analyses. This study is the first one to report an association between a TRAIL polymorphism and lymphoma risk and suggests a possible role of TRAIL in B cell lymphomagenesis.