| In many part of the world, the incidence of thyroid cancer is increasing faster than any other human malignancy. The papillary thyroid carcinoma (PTC) is the most common subtype, with the incidence grows extremely fast in the past15years. The radio of PTC rose from70%to90%. The prognosis is well when treated with surgical operation, Thyroid-stimulating hormone suppressiontherapy, and radioiodine therapy (RIA). Though the mortality is infinitesimally small, the regional metastasis, poor prognosis, and refectory of radioiodine therapy is very common. To indicate these ’high-risk’ patients, formulate personal treatment projection, set up proper follow up, increase the prognosis and living quality are the most important subject for clinician in thyroid department.The BRAFV600E mutation is the most valuable marker for PTC. BRAF is a B-type Raf kinase, located in chromosome7, andis the most potent activator of the mitogen-activated proteinkinase/extracellular-signal-regulated kinase (MEK-ERK) pathway.The mutation of this gene leads to the activity of MEK kinase and plays an essential role in mediating cellular differentiation,proliferation, senescence, and survival. The existing researches show that:1. The incidence of BRAFV600E mutation is veryhigh in PTC, and this phenotype is exclusively emerged in PTC.2. The patients who harbored BRAFV600E mutation have a poor prognosis, with the invasive clinicopathologic features, more likely resist to RIA, and higher mortality. But in recent years, more and more opposite results come into view. These researchers suggests that there are no relationship between BRAFv600E mutation and poor prognosis of PTC, many’low-risk’patients can also detect this mutation. Does this genetic events have effect on biological behaviour of PTCs is remain controversal.Much studies in this topic are concentrate on the relationship of BRAFV600E mutation and prognostic features. The effective of clinicopathologic characteristics on BRAFV600E mutation is lack of discussion. Whether the mutation’s effect is analogical with different clinicopathologic characteristics are still unknown.With this train of thought, we set up a comprehensive study to discuss the practical clinical application of BRAFV600E, which is ahead in these field in China. Firstly, we discuss the potential effective of clinical features on BRAFV600E mutation, like age, gender, the serum indicator of thyroid function and immunology. To analysis the mutation rate with different clinical features. Secondly, we discuss the relationship between BRAFV600E mutation and prognostic factors, like cervical lymph node metastasis(CLNM), extrathyroidal extention(Ex), the histopathologic subtypes of PTC, the TNM stage, and the MACIS score. To analysis the relationship with different clinicopathologic features. Thirdly, we discuss the effect of BRAFV600E mutation on the expression of sodium-iodine symporter (NIS), to analysis the influence of clinicopathologic features on NIS expression, reflect the potential predictive value of RIA outcome indirectly. With these researches, we could not only study the independent value of BRAFv600E mutation, but also can summarize the complicated clinical practise with this useful methods.PART ONEPractical Clinical Application of BRAFV600E on Diagnosis in Papillary Thyroid CarcinomaObjective:To compare the rate difference of BRAFV600E mutation in PTCs and benign thyroid tumors, and discuss the relationship between BRAFV600E mutation and clinical characteristics.Methods:A retrospective study was performed with patients who were diagnosed as PTC and Nodular goiter(NG) from June2013to June2014in Wuhan Tongji Hospital. To extracte the DNA from FFPE, RT-qPCR assay was used to detect the BRAFV600E mutation. Chi-square test, threshold effect, multivariate Logistic Regression analysis was performed with clinical characteristics(age, gender, TSH, FT3, FT4, Tg, Tg-Ab, TPO-Ab, TSHR-Ab) and BRAFv600E mutationResults:134PTCs and37NGs were collected in our analysis.1. The mutation rate(MR) of BRAFv600E was68.7%in PTCS, while0%in NGs.2. In PTCs, relationships between BRAFV600E mutation and age, Tg-Ab level were noticed. While mutation were not relate to gender, TSH, TSH, FT3, FT4, Tg, TPO-Ab, TSHR-Ab.3. The mutation rate was extremely high in the older patients(>38y), with OR=2.63,95%C1=1.17,5.92p=0.020. The rate was lower in patients with abnormal Tg-Ab level or TPO-Ab level, diagnosed with clinical test upper limit(OR=0.357,95%C1=0.129,0.985, p=0.047; OR=0.333,95%C1=0.129,0.86, p=0.023).Conclusions:BRAFV600E mutation almost could not detected in NGs, when detected this mutation, the nodules could basically diagnosis as PTCs. When the nodules were suspected, and were not detect this mutation, operation and strict follow-up would be properable in patients with younger age and abnormal Tg-Ab or TPO-Ab. PART TWOClinical Application of BRAFV600E on Prognostic Prediction in Papillary Thyroid CarcinomaObjective:To discuss the relationship between BRAFV600E mutation and prognostic factors, analysis the clinicopathologic features’ influence on this relation. Methods:A retrospective study was performed with patients collected in Part I who were diagnosis as PTCs. Statistical analysis were used to study the clinicopathologic factors which influence the CLNM and Ex, the independent value of BRAFV600E mutation on CLNM and Ex. To discuss relationship between mutation and the pathological variants, TNM stage, MACIS score.Results:1. Age (OR=0.908, p<0.001), tumor maximum diameter(Dmax)(OR=1.07, p=0.01) was the independently influence CLNM; The role of BRAFV600E mutation on CLNM was different with different age; Multivariate Logistic Regression analysis showed an acceleration of mutation on CLNM, but had no significance(OR=1.16,p=0.775).2. Tumor total diameter(Dtotal) promoted Ex (OR=1.04, p=0.064), Multivariate Logistic Regression analysis showed an independent acceleration of mutation on Ex.3. The MACIS score was high in mutant type term, with a significant difference(β=0.42, p=0.027).4. In these PTCs, there were111classic variant PTCs, with MR=72.0%;13tall cell variant PTCs, MR=92.3%;10follicular variant PTCs, with no BRAFV600E mutation.5. More advanced tumors were noticed in mutant term(14.1%vs.4.8%).Conclusions:BRAFV600E mutation may not play role in CLNM, but was related to extrathyroidal extention(Ex), invasive histopathologic subtype, advanced TNM stage, and high MACIS score, it may predict poor prognosis. PART THREEStudy of BRAFV600E Mutation on the Expression of NIS in Papillary Thyroid CarcinomaObjective:To discuss the relationship between BRAFV600E mutation and the expression of NIS, analysis the clinicopathologic features’influence on this relation. Methods:Western Blotting technology and RT-qPCR assay were performed to detect the expression level of NIS in PTC tissue samples. Immunofluorescence histochemistry was used to detect the position of NIS. Immunohistochemistry was used to detect the expression of NIS in FFPE samples, IPP6.0software was used to calculate the IOD density of each sample, statistic analysis the clinicopathologic features and IOD density.Results:1. Western blotting shows that the NIS total protein was higher in carcinoma tissue than para-carcinoma, but the membrane protein was lower, with no significance. Both the total and membrane protein were lower in mutant type term, also with no significance.2. RT-qPCR showed that, the transcription level of NIS gene SLC5A5was lower both in para-carcinoma and wild type term.3. In para-carcinoma tissue, the NIS was noticed partly located on membrane of normal thyroid cells, with lower expression, NIS was more located on nuclear and cytoplasm in carcinoma tissue.4. The expression of NIS had no relation with clinicopathologic features, the level of IOD identify was lower in mutant type, which is more significant in PTCs not combined with hashimoto’ thyroiditis(HT). Multivariate Regression analysis showed BRAF mutantion independently deceased the NIS expression in PTCs without HT((β=-0.0257, p=0.046)Conclusions:The expression of NIS was inordinate, while the functional expression may decrease. BRAFV600E mutation may influence the expression of NIS, which may more valuable in PTCs without HT. |
PDF Full Text Request