ErbB3 protein expression in serous ovarian carcinomas of elderly women

Abstract

16026 Background: Ovarian carcinoma is the leading cause of death due to gynecologic malignancies, and older age at the time of diagnosis has been suggested to correlate with poorer outcome. Recent studies suggest that expression of ErbB3, a member of the epidermal growth factor receptor family, is associated with decreased survival. The goal of this study was to examine ErbB3 protein expression with a tissue microarray (TMA) comprised of advanced papillary serous (PS) ovarian carcinomas, and to correlate results with clinical information to evaluate for expression differences in younger and older women. Methods: A high density TMA (with 4 cores per primary tumor) was constructed by retrospective review of PS ovarian carcinoma cases seen between 1999 and 2005. Patients were divided into 2 cohorts based on age (=65 and =55 at diagnosis). Only cases of stage III or IV disease were included, and patients with BRCA mutations were excluded. Clinical data were obtained by chart and database review. TMA sections were immunostained for ErbB3, and expression was correlated with age, stage, and overall survival. Results: 136 primary tumors were available: 72 in the =65 group, 64 in the =55 group. Tumors from the =65 cohort were significantly less likely to express ErbB3 (16.7%) when compared to the ≤55 cohort (51.6%) (p<0.0001). Patients whose tumors expressed ErbB3 had decreased median survival (33.6 months) compared to ErbB3 negative cases (47.3 months), but these results were not statistically significant (p=0.10). ErbB3 expression correlated in a borderline significant manner with stage (dichotomized as IIIa/IIIb vs. IIIc/IV) at the time of diagnosis (stage IIIa/b 11.8%+ vs. stage IIIc/IV 36.1%+; p=0.055). Multivariate analysis with respect to age, stage, and ErbB3 status did not reveal ErbB3 to be a statistically significant predictor of poor outcome in this data set. Conclusions: These results demonstrate that PS ovarian carcinomas in patients aged =65 at the time of diagnosis are significantly less likely to express ErbB3 than those ≤55. Correlation between ErbB3 expression and more advanced stage at the time of diagnosis bordered on significance. There was a non-significant trend towards decreased overall survival in both univariate and multivariate analyses in patients whose tumors exhibited ErbB3 expression. No significant financial relationships to disclose.