The Studies Of Prognostic Factors And The Genetic Polymorphism In Thymic Epithelial Tumors

Objective:Describe the clinical characteristics and prognostic factors of a group of thymic epithelial tumors(TETs).We also investigated the association between genetic polymorphisms of methylenetetrahydrofolate reductase(MTHFR)C677T and the incidence of TETs.Methods:Pathological data from January 2010 to December 2020 at the Second Affiliated Hospital of Jiaxing University were reviewed and a total of 84 TETs were included.Prognostic factors were determined by univariate and multivariate analyses.Genetic polymorphisms of MTHFR C677T were tested in TETs and a cohort of healthy individuals.The association between MTHFR transcriptional levels and methylation was analyzed using the Cancer Genome Atlas(TCGA)thymoma dataset from the cBioPortal platform.Results:Kaplan-Meier univariate survival analysis showed a statistically significant correlation between age,sex,maximum tumor diameter,surgery,radiotherapy,chemotherapy,MasaokaKoga stage,8th UICC/AJCC TNM staging,and WHO histological classification with patient prognosis.The 8th UICC/AJCC TNM staging and Masaoka-Koga stage were significantly correlated(r=0.925,P<0.001).Cox multivariate survival revealed that the maximal tumor diameter,8th UICC/AJCC TNM staging and Masaoka-Koga stage were independent prognostic factors for TETs(P<0.05).MTHFR C677T allele distribution(χ2=5.750,P=0.016)and genotype(χ2=7.987,P=0.018)showed significant differences between patients and healthy controlsTT homozygous and CT heterozygous genotypes of the MTHFR polymorphism significantly increased the risk of developing TETs(odds.ratio[OR]=4.721,P=0.008).According to kaplan-Meier univariate survival analysis,different genotypes were not associated with TETs prognosis(CC versus CT+TT,χ2=0.003,P=0.959).Finally,we found a negative correlation between transcription and methylation levels of MTHFR(r=-0.24,P=0.010)in analysis of thymoma TCGA data(r=-0.24,P=0.010).Conclusions:Higher tumor maximal diameter,higher TNM stage 8 of UICC/AJCC,and later Masaoka-Koga stage were independent factors affecting TETs.Decreased methylation levels of MTHFR and specific phenotypes increase susceptibility to thymic epithelial tumors.