The Prevalence of RET/PTC Mutations in Papillary Thyroid Cancers in Turkish Population and its Relation Between Tumor Histopathology and Prognostic Factors

Abstract

Objective: In recent years, thyroid cancer has been at the forefront of molecular pathology as a result of the consequences of the Chernobyl disaster and the recognition of the role of RET/PTC rearrangements in papillary thyroid carcinomas (PTCs). Correlation of RET/PTC expression with clinical outcome is controversial. This study aims to identify the prevalence of RET/PTC oncogene expression in Turkey, and to investigate the correlation between RET/PTC oncogene expression and the known prognostic factors of PTC in 101 patients.

Methods: The RET rearrangements were examined by means of reverse transcriptase-polymerase chain reaction analysis, with primers flanking the chimeric region. Statistical evaluation was performed by using Independent samples t-test, One-sample Chi-square test and Pearson Chi-square or Fisher's Exact Test.

Results: RET/PTC was determined positive in 67(66.3%) of totally 101 patients (p<0.001). RET/PTC1 in 32(31.7%), RET/PTC3 in 21(20.8%), RET/PTC1+RET/PTC3 both in 10(9.9%) patients were found to be positive. There was RET/PTC2 positiveness in two patients, RET/PTC2,3 positiveness in one patient, and RET/PTC1,2,3 positiveness in one patient. No statistical difference was found between RET/PTC1 and RET/PTC3. None of genetico-clinical analyses showed any significant association between RET/PTC expression and the clinical and pathological features of the cancers.

Conclusion: While this prevalence of the RET/PTC is less than RET/PTC frequency seen after Chernobyl in Belarus, its prevalence in our region is also high (66.3%). As a result, no significant correlation was found in between prognosis and RET/PTC frequency.

RET/PTC mutations - Turkish Population - prognostic factors

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