Evaluation of TP53 and HER-2/neu Genes Expression Levels in Gestational Trophoblastic Diseases Cases and Determining Their Predictive Value in Diagnosis of Malignancy and Disease Progression

Background: Gestational trophoblastic disease (GTD) is a general term that includes several types of pathologically different diseases, which range from hydatidiform mole to choriocarcinoma. Early differentiation of these types is important to determine treatment strategy and prognosis. Objectives: Genetic markers such as TP53 and HER-2/neu expression are recently shown to have diagnostic and prognostic values. The aim of this study was to evaluate its significance. Methods: We enrolled 62 patients diagnosed with GTD referred to Imam Hossein Hospital in Tehran, Iran between 2012 and 2017. Endometrial pathologic specimens were stained, using the immunohistochemistry (IHC) method for the expression of TP53 and HER-2/neu genes. Expression levels determined by IHC were compared between final pathologic diagnoses, using one-way ANOVA test (analysis of variances), which detects significant differences between the means of 3 or more independent groups. Results: Out of 62 participants, 32 and 24 cases were diagnosed as partial and complete hydatidiform mole, respectively. Four cases had invasive hydatidiform mole and only 2 cases were diagnosed as choriocarcinoma. Analysis using ANOVA demonstrated that expression levels of both TP53 and HER-2/neu genes are significantly higher among patients with invasive form and choriocarcinoma compared with non-invasive hydatidiform mole (P < 0.05 for both genes). The receiver operating characteristic (ROC) curve for each gene showed that more than 55% positive staining for the TP53 gene can differentiate non-invasive hydatidiform mole from invasive form and choriocarcinoma with 100% sensitivity, and 92.9% specificity. Conclusions: TP53 expression might serve as a potential diagnostic aid to differentiate benign and malignant GTDs and a future target for adjusting treatment based on the expression levels.