Abstract 775: Evaluation of Erb-B2 expression from archival tumor tissue in early stage epithelial ovarian carcinoma patient prognosis

Abstract

Abstract In this retrospective study, Erb-B2 expression was assessed in 106 patients using Paraffin-Embedded Tissue (PET) to determine the prognostic value in Epithelial Ovarian Carcinoma (EOC) patients diagnosed at Saskatoon Cancer Center between the years 1983-1995. Relationship between Erb-B2 positivity and patient tumor characteristics was assessed for Overall Survival (OS) and Relapse-Free Survival (RFS) by Kaplan-Meier method. Based on the intensity of stain with a polyclonal antibody (A485, 1/400 dilution), cases with markedly intense cytoplasmic and membranous immunoreactivity were classified as Erb-B2 over-expressors. Erb-B2 was overexpressed in 13 (12%) cases. The mean age of the patients was 56 years (range 18-84 years). The patient population consisted of 64 Stage I and II, Early Stage (ES) and 36 cases with Stage III and IV Advanced Stage (AS). Data on histologic grade was available in 81 cases. 58 patients received platinum-containing regimen, 13 melphalan, and in 9 cases combination chemotherapy. Erb-B2 expression did not influence OS and RFS in these patients. Similarly, there was no significant relation to OS and RFS between Erb-B2 and age, grade, and patients with No Evidence of Disease (NED). Of the 64 cases with ES disease, 16 cases had Grade 2 tumor with Erb-B2 over-expression in 4 cases. Grade 2 tumors with Erb-B2 overexpression indicated significant relationship to OS and RFS, p=0.01, (median = 30 months, CI: 26 - 68) and p=0.05, (median = 15 months, CI: 13 - 68). Furthermore, in 21 cases with ES, Endometrioid histology and Erb-B2 expressors 6/21 (28%) experienced significantly shorter OS compared to non-expressors p=0.005, (median = 48 months, CI: 22 - 74) (mean = 134 months, CI: 124 - 144). In conclusion, Erb-B2 overexpression could be detected in only limited EOC cases in PET and appears to have no prognostic influence. Additionally, endometrioid carcinoma and grade 2, ES certainly reflect the importance of sub-group analysis. In ovarian carcinoma distribution of stage, histology, and grading of tumor cells are conventional markers for prognosis. Finally, Erb-B2 status detected by immunohistochemistry, in a subgroup of patients with high-degree of HER2 positivity/focal amplification may likely have better clinical outcome with anti-HER2 agents. Citation Format: Kavitha Advikolanu Rao, Anthony Magliocco, Andrew Maksymiuk. Evaluation of Erb-B2 expression from archival tumor tissue in early stage epithelial ovarian carcinoma patient prognosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 775.