Expression of FHIT, p16, p53 and EGFR as prognostic markers in thyroid tumors of uncertain malignant potential

Abstract

Purpose: Thyroid tumors of uncertain malignant potential (TT-UMP) constitute a relatively new diagnosis. The purpose of this study was to analyze the relationship between immunohistochemical panels, prognostic parameters and TT-UMP. Methods: Group I was composed of patients diagnosed as differentiated thyroid carcinoma (DTC) and Group II of patients diagnosed as TT-UMR The prognostic scores of patients were calculated using data according to the well-known prognostic scoring systems MACIS, AMES, AGES. Evaluations of antibodies were based on the presence of nuclear staining for p16 and p.53, membranous and cytoplasmic staining for epidermal growth factor receptor (EGFR) and cytoplasmic staining for fragile histidine triad (FHIT). Results: Statistically significant difference was noted (p< 0.05) between Group I and Group II according to MACIS and AMES. No statistical difference was found in terms of immunostaining between groups when stained with p16, p.53 and FHIT. On the other hand, in Group II a moderate positive correlation was detected between MACIS and EGFR. Conclusion: According to our findings p53 was not important in tumor genesis at early stages in well-differentiated thyroid carcinomas and p16 loss of expression could be used as a finding to help in difficult microscopic diagnosis. TT-UMP is a gray zone of lesions requiring specific therapeutic procedures and postoperative follow-up. A positive correlation was detected between EGFR and TT-UMP, leading to assume that this situation could be used as a new tool in the follow-up of these patients in the future.