Percentage of BRAFV600E Alleles and Outcome in Thyroid Carcinoma

BRAFV600E is the most frequent oncogene in Papillary thyroid carcinoma (PTC). It correlates with greater extension, lymph node metastasis, and advanced stage. However, the prognostic value of BRAFV600Eis weak and the search of this mutation is not recommended in clinical management of thyroid cancer. PTC are characterized by intratumor heterogeneity with wild-type and BRAFV600E tumoral cells. In a previous study, the BRAFV600E/BRAFwild-type ratio correlated with patient age, tumor volume, lymph node metastasis and with worst disease outcome. While the existence of intratumor heterogeneity in PTC is supported by many evidences, its extension, biological significance and clinical utility is questioned and must be further investigated. Primary endpoint of the study is to determine the relationship between the percentage of BRAFV600E alleles and outcome in PTC patients. Secondary endpoints are to determine the mean and median BRAFV600E/BRAFwild-type allele ratio in heterogeneous tumors; determine the relationship between the percentage of BRAFV600E alleles and clinicopathological features. The study protocol entails the assessment by digital-droplet PCR the BRAFV600E/BRAFwild-type allele ratio in a series of PTC and its correlation with clinicopathology features and outcome.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

* Patients undergone surgery because of any PTC subtypes 3 years before or more
* Availability of PTC tissue samples, well annotated
* Availability of clinical data of the patients including gender, age at diagnosis, type and extension of surgery, radiation therapy, radio-iodide therapy, TSH suppressive therapy
* Follow up of 3 years or more after surgery, including periodical 6 months assessment of TSH, thyroglobulin and AbTG, neck ultrasound evaluation and episodic hrTSH stimulation test

Exclusion Criteria:

* Inadequate tissue samples or clinical data and follow up
* Purity of PTC samples \< 50%

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