Association of a DNA damage response deficiency (DDRD) assay and prognosis in early-stage esophageal adenocarcinoma.

4015 Background: The incidence of esophageal adenocarcinoma (EAC) has increased 6-fold in the last 30 years and in early stage EAC 5-year survival remains poor at 25-35%. Neoadjuvant therapy confers a significant improvement in outcomes but the optimal approach for individual patients remains unclear. We assessed a 44 gene DNA Damage Response Deficient (DDRD) assay, previously developed to detect loss of the Fanconi Anaemia (FA)/BRCA pathway in breast cancer, as a predictor of prognosis following DNA damaging chemotherapy in EAC. Methods: This study was conducted using 63 formalin fixed paraffin embedded (FFPE) pre-treatment endoscopic biopsy specimens from early stage EAC patients treated with cisplatin-based neoadjuvant chemotherapy followed by surgical resection between 2004 and 2010 at the NI Cancer Centre. EAC biopsies were profiled using the Xcel array, a cDNA microarray-based technology optimized for archival FFPE tissue (Almac/Affymetrix), and scored for the DDRD assay. The association between the...