Monday June 6, 5:00 p.m. to 6:00 p.m. CT, Hall D2
Abstract No. 7530
: Use of negative TTF-1 status to predict for negative EGFR mutations status with a high negative predictive value in patients with adenocarcinomas of the lung.
Archival specimens from patients with NSCLC were tested for EGFR mutations by allele-specific PCR; TTF-1 status was determined by examining patients’ pathology reports. Of the 693 specimens tested, TTF-1 status was known in 301, and of those, 224 (74 percent) harbored EGFR mutations – only two of the EGFR mutation-positive specimens were TTF-1 negative and 28 of the 77 EGFR wild type specimens were TTF-1 negative. As TTF-1-negative lung adenocarcinomas have a 99 percent probability of also being negative for EGFR mutations, results suggest the benefit of initiating chemotherapy treatment in the 30 percent of patients who test positive for TTF-1 as their EGFR mutation status is verified.
Monday June 6, 5:00 p.m. to 6:00 p.m. CT, Hall D1
Abstract No. 4023
: Association of ERCC1 gene expression with outcome in stage II-III esophageal adenocarcinoma patients treated with preoperative platinum-based chemoradiation in a phase II cooperative group study (SWOG S0356).
Expression of genes associated with drug metabolism (DPD, GSTPi, TS and TP) and DNA repair (ERCC1 and XPD) were tested to determine their association with clinical outcome in esophageal cancer. Thirteen polymorphisms in drug metabolism (GSTP, MTHFR and TS) and DNA repair (ERCC1, RAD51, XPD, XRCC1 and XRCC3) genes were also investigated to determine if specific patterns were predictive. In a univariate analysis of data derived from 92 patients, only ERCC1 gene expression levels were associated significantly with progression-free survival and overall survival, with high ERCC1 levels were predictive of lower two-year progression-free survival (17 versus 67 percent, p=0.0058) and two-year overall survival (37 versus 72 percent, p=0.047) compared to low levels. ERCC1 levels were not associated with complete pathologic response. These data suggest that assessing ERCC1 levels can help identify patients with stage II-III esophageal adenocarcinomas that are likely to experience longer survival when treated with preoperative oxaliplatin-based chemoradiation.