Exploratory analysis of angiotensin converting enzyme (ACE) and aldosterone (Ald) serum levels as prognostic and predictive biomarkers on the NCIC CTG BR24 trial.

8048 Background: Benefit from angiogenesis inhibitors (AI) has been linked to high blood pressure. One of the main determinants of blood pressure is the renin-angiotensin axis. We undertook an exploratory, retrospective analysis of ACE and Ald serum levels on specimens banked during the conduct of the BR24 study. The aim was to evaluate these markers for their prognostic significance and their predictive value regarding Cediranib (Ced) treatment. Methods: The NCIC CTG BR24 study randomized advanced non-small cell lung cancer patients (pts) to carboplatin and paclitaxel (CP) +/- Ced. ACE and Ald serum levels were retrospectively tested on baseline samples using commercial ELISA kits. A graphic method, differentiating treatment effect by the range of marker, was used to determine cutoff points (JCO 2010, 28: 5247). Exploratory analyses were performed to correlate biomarkers levels with pts characteristics and overall survival (OS). Association between categorical variables was assessed by Chi-square test or...