Background: Within the past two decades, the incidence of thyroid cancer has increased across the globe. In the differential diagnosis of benign tumors from malignant tumors in the thyroid gland, hypermethylation of the RASSF1A gene is used. The aim of this study is comparing the validity of quantitative and qualitative methods of the RASSF1A gene hypermethylation molecular test in the diagnosis of thyroid malignancies.
Methods: One hundred sixty samples from patients with malignant thyroid tumors (80 samples) and benign thyroid tumors (80 samples) were entered into this study from all patients referred to Ahvaz Medical Centers. First DNA was extracted from samples embedded in paraffin. After DNA extraction, hypermethylation of the gene was done by COBRA method. Finally, to calculate the effects of sensitivity, specificity, predictive value and accuracy of the test, epidemiological calculations were done.
Results: The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the qualita-tive method of the RASSF1A gene hypermethylation molecular test in the diagnosis of thyroid malignancies are: 91.25%, 15%, 51.77%, 63.15%, and 53.12%, respectively and for the qualitative method are: 27.5%, 98.75%, 95.65%, 57.66%, and 6.12%, respectively.
Conclusions: The quantitative level of hypermethylation differentiated groups of benign tumors from malignant groups better than the qualitative evaluation but the qualitative studies are not applicable for this purpose.