Document Type: Original Research
Department of Pathology,Yas Hospital, Tehran University of Medical Sciences,Tehran, Iran
Department of Pathology, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran
Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
Background & Objective: Endometrial carcinoma (EC) has been traditionally classified into two distinct categories of low-grade and high-grade. Type I (low grade) EC, which constitutes the majority of cases, is linked to estrogen-related molecular pathways. But type II (high-grade) EC accounts for 10-20% of cases and behaves in an aggressive way. Pathologic and biological features of type II EC have not been fully elucidated yet. Several investigations have demonstrated HER2/neu expression and amplification in type II EC, especially papillary serous carcinoma (PSC).This study assessed HER2/neu expression in high-grade EC as well as its association with other clinical and histopathological prognostic factors.
Methods: In this cross-sectional study, we performed HER2/neu immunohistochemical (IHC) staining in 37 high-grade EC cases with histological diagnostic categories of PSC (n=23), clear cell carcinoma (CCC) (n=9), and carcinosarcoma with high-grade carcinomatous component (PSC, CCC, grade 3 endometrioid carcinoma, or unclassified high-grade adenocarcinoma) (n=5). All patients were followed for 2-9 years in order to evaluate their disease-free survival (DFS) and overall survival (OS) during study period (2005-2014).
Results: HER2/neu IHC staining was positive in 12 patients (32.4%) including 8/23 (34.8%) PSC, 2/9 (22.2%) CCC, and 2/5 (40%) carcinosarcoma cases. There was no statistically significant difference between HER2/neu expression and DFS or OS of the patients (P>0.05).
Conclusion: We observed that HER2/neu is expressed in one-third of high-grade ECs. This ancillary test is supportive in follow-up of patients with high-grade ECs.