Radyoterapi Uygulanan Olgularımızda MDR1 Gen Polimorfizm ile Tedavi Etkinliği Arasındaki Korelasyonun İncelenmesi

Abstract

The relation between the polymorphism of the gene encoding for p-glycoprotein (MDR1), responsible for the excretion of many drugs and endogenous substances found in the cell membrane, and cancer or chemotherapy (CT) has been previously studied. However, there is limited information about the mentioned polymorphism and the efficacy of radiotherapy (RT). In our study, we aimed to investigate the effect of MDR1 gene polymorphisms C3435T, G2677A/T and C1236T on the clinical efficacy of RT. Retrospectively, 139 cancer patients were included, the frequency and timing of local recurrence development and response assessment of applied RT according to RECIST criteria were examined. Polymorphism in MDR1 gene was detected by PCR-RFLP method. The difference in the frequency of RT response and local recurrence development among patients with wild-type homozygous, heterozygous and mutant homozygous alleles was assessed by chi-square method; Kaplan-Meier log rank was used to assess the difference in the time of local recurrence. When all patients were examined, there was no difference in the RT response between genotypes and genotype combinations, or the risk of developing local recurrence after RT (p> 0.05). In the subgroup analysis of five cancers constituting our study group, local progression-free survival was found to be lower in gastrointestinal system carcinoma patients carrying the 1236TT homozygous variant, p = 0.013. The effect of the 1236TT variant on local progression-free survival was significant after multivariate analysis. In conclusion, in this retrospective series, in patients with gastrointestinal cancer (colorectal, stomach, pancreas) the MDR1 1236TT variant was associated with shorter local progression-free survival. There was no relationship between RT activity and MDR1 polymorphism in breast and lung cancer patients.