Abstract 4593: Expression of Ecdysoneless in breast cancer progression predicts poor outcome in breast cancer patients

Breast cancer is the most common type of cancer and second leading cause of cancer-related deaths in women in the United States. Our laboratory has identified the protein hEcd (human ortholog of Drosophila Ecdysoneless) as a novel regulator of cell cycle. Previous studies showed that Ecd regulates cell cycle by regulating the Rb-E2F pathway. Given the dysregulation of the cell cycle machinery in cancer, we examined expression of Ecd in normal, benign, ductal carcinoma in situ (DCIS) and infiltrating ductal carcinoma (IDCs) of breast. In first cohort, we showed while normal and hyperplasia of breast barely showed Ecd expression, high Ecd expression was observed in DCIS and IDC patient tissue specimens. In this cohort of 104 IDC patents, Ecd expression was positively associated with higher grade (p=0.04).We then analyzed Ecd expression in a second larger cohort (954) and observed similar results, where increased Ecd expression was associated with tumors of higher histological grade (p=0.013), mitotic count (p=0.032), and Nottingham Prognostic Index score (p=0.014). Notably, Ecd expression was positively associated with HER2/neu (p=0.002) overexpression. Significantly, a positive association between Ecd expression and shorter breast cancer specific survival (BCSS) (p=0.008) and disease-free survival (DFS) (p=0.003) was observed in HER2/neu overexpressing patients. Taken together, our results demonstrate Ecd expression as a novel marker for breast cancer progression that predicts tumor progression and the clinical outcome in breast cancer patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4593. doi:1538-7445.AM2012-4593