BRAF^V600E Mutation And Glycolipid Metabolism Related Gene Detection In Diagnosing Thyroid Cancer

Objectives: 1.To compare the diagnostic efficacy of BRAFV600 E mutation and thyroid imaging reporting and data system(TIRADS)classification in diagnosing papillary thyroid cancer(PTC)in nodules with BSRTC I,III and V categories.2.Disturbance of glucose and lipid metabolism is an important metabolic feature of tumor cells.In this study,we aimed to evaluate the value of glycolysis-related genes(GLUT1,PKM2,LDHA and PDK1)and fatty acid synthesis key enzyme gene(FASN,ACS,ACLY and ACACA)expression of thyroid nodules fine-needle aspiration(FNA)specimens in diagnosing thyroid cancer,and analyze the correlation with clinical features.Methods: 1.Prospective detection of BRAFV600 E mutation on FNA specimens began from January 2014 to March 2018.Clinical information,TIRADS classification,BRAFV600 E mutation detection and cytopathological results were collected.As a result,a total of 472 patients with 479 nodules were enrolled in this study.Then,to compare the sensitivity,specificity,PPV,NPV and accuracy of TIRADS and BRAFV600 E mutation detection in diagnosing PTC in BSRTC I,III and V nodules.2.This was a prospective study.RT-q PCR was used to detect m RNA expressions the of glycolysis-related genes and fatty acid synthesis key enzyme in 146 cases of thyroid nodules(47 benign and 99 malignant)and 78 cases of nodular peripheral thyroid fine needle aspiration(FNA)specimens.Then,Glycolysis-related protein(GLUT1,PKM2 and LDHA)expressions were detected by immunohistochemistry.Logistic regression was used to establish regression equations of the combination diagnosis.Furthermore,the receiver operating characteristic(ROC)curve was constructed to calculate AUC,sensitivity,specificity,PPV and NPV of the above genes in diagnosing thyroid cancer.Results: 1.1)In BSRTC I category,BRAFV600 E had similar sensitivity,higher specificity and lower accuracy compared with TIRADS.In BSRTC III/V category,the sensitivity,specificity and accuracy of BRAFV600 E were similar to TIRADS.2)Notably,when compared with BRAFV600 E,the combination of these two methods significantly improved sensitivity(BSRTC I: 93.6% vs 67.7%,P<0.01;BSRTC III: 93.8% vs 75.0%,P<0.01;BSRTC V: 96.0% vs 85.3%,P<0.001).When compared with TIRADS,the combination increased sensitivity in BSRTC I nodules(93.6% vs 74.2%,P<0.05),improved sensitivity and decreased accuracy in BSRTC III nodules(93.8% vs 75.0%,P<0.01;91.0% vs 93.6%,P<0.01),and improved sensitivity and accuracy in BSRTC V nodules(96.0% vs 82.0%,P<0.001;94.2% vs 81.3%,P<0.001).2.1)There was no significant difference in the expression levels of glycolysis-related genes(GLUT1,PKM2,LDHA and PDK1)between benign nodules and normal thyroid cells(P>0.05).Compared with benign nodules and normal thyroid cells,the expression of GLUT1,PKM2 and LDHA in thyroid cancer significantly increased(P<0.05).However,PDK1 exhibited no significant difference between benign and malignant thyroid nodules.The sensitivity,specificity,accuracy and AUC(95% CI)of GLUT1,PKM2 and LDHA genes in the diagnosis of thyroid cancer were 54.6%,87.2%,65.1%,0.711(0.631-0.783);47.5%,95.7%,62.3%,0.676(0.594-0.751)and 55.6%,78.7%,63.1%,0.634(0.550-0.712),respectively.When the three genes combined,the AUC(95% CI),sensitivity,and accuracy reached the highest,0.731(0.652-0.801),61.6% and 70.5%,respectively.2)The expressions of GLUT1,PKM2 and LDHA protein in thyroid cancer were significantly higher than that in normal thyroid tissue and benign nodules.And the levels of protein expressions were consistent with the corresponding gene expressions in FNA specimens.3)The expressions of GLUT1,PKM2 and LDHA in thyroid cancer were not significantly associated with age,gender,number of nodules,BRAFV600 E mutation and lymph node metastasis(P>0.05),but significantly correlated with the maximum diameter of tumor and AJCC stage.4)5)There was no significant difference in the expression of fatty acid synthesis key enzyme genes(FASN,ACS,ACLY and ACACA)among normal thyroid cells,benign nodules and thyroid cancer(P>0.05).Conclusions:1.BRAFV600 E exhibited higher specificity and lower accuracy compared to TIRADS in BSRTC I nodules,while they showed similar diagnostic value in BSRTC III/V nodules.The combination of them distinctly improved sensitivity in diagnosing PTC in BSRTC I,III and V nodules.2.The combination of glycolysis-related genes(GLUT1,PKM2 and LDHA)exhibited the highest value in the diagnosis of thyroid cancer,which can be used as an important auxiliary for the differential diagnosis of benign and malignant thyroid nodules.In addition,these genes may have a certain value in the prognosis of thyroid cancer.