Prelininary Study On The Relationship Between BRAF And RAS Mutation And Prognostic Factors In Classic Papillary Thyroid Carcinoma With Cervical Lymph Node Metastasis

Objective: Detecting the incidence rate of BRAF V600 E,N-RAS and K-RAS mutation in classic papillary thyroid carcinoma with cervical lymph node metastasis.Exploring the relationship between BRAF V600 E mutation status and clinicopathologic characteristics,such as gender,age,tumor size,tumor invasion into extrathyroid tissues,number of tumor lesions,central lymph node metastasis,number of metastatic lymph nodes,Tg and disease-free surival(DFS)after initial operation in 30 CPTC with cervical lymph node metastasis but no distant metastasis.Methods: We detected the BRAF V600 E,N-RAS and K-RAS mutation status of 30 CPTC patients who met the study requirements by real-time fluorescent quantitative PCR method and then calculate the mutation rate of them respectively.Their genomic DNA was extracted from paraffin-embedded thyroid tissue sections.Their genomic DNA was extracted from paraffin-embedded thyroid tissue sections.The correlation between BRAF V600 E mutation status and the clinicopathologic features and prognosis of 30 CPTC patients with cervical lymph node metastasis was analyzed by SPSS21.0,in which Fisher exact test was used for univariate analysis,logistic regression analysis was used for multivariate analysis,nonparametric test was used for measurement data and Kaplan-Meier analysis with log-rank test was used for survival analysis.Results: 1.We detected BRAF V600 E,N-RAS and K-RAS mutation status in 30 CPTC patients.The prevalencce of them were 70%,3.3% and 0%,respectively.2.Univariate analysis revealed that BRAF V600 E mutation status was correlated significantly with both gender and age but not with tumor size,tumor invasion into extrathyroid tissues,number of lesions and central lymph node metastasis.Multivariate analysis indicated that BRAF V600 E mutation status was irrelevant to all of the factors above.Nonparametric test showed no significant relationship between BRAF V600 E mutation status and number of cervical lymph nodes and serum Tg levels before and after radioiodine ablation therapy.3.After radioiodine ablation therapy with the same dose,the serum Tg levels of CPTC patients with cervical lymph node metastasis in BRAF V600 E mutation-positive group were higher than mutation-negative group,but there was no significant difference between them.4.During the follow-up,there was no one experienced recurrence in all CPTC patients.Conclusion: 1.In CPTC patients with cervical lymph node metastasis,the prevalence of the BRAF V600 E,N-RAS and K-RAS mutation were 70%,3.3% and 0%,respectively.2.For CPTC patients with cervical lymph node metastasis,BRAF V600 E mutation may not served as a predictor of the risk of aggressive tumor characteristics and poor prognosis.