Correlation of ERCC1 mRNA expression with KRAS mutation status in colorectal, pancreatic, and lung adenocarcinoma.

11062 Background: KRAS is mutated in about 40% of colorectal cancers; it is the only validated predictive marker used in patients with metastatic disease. ERCC1 is a critical enzyme in nucleotide excision repair and is associated with response, progression free and overall survival in patients with NSCLC, colorectal, and gastric cancer treated with platinum based chemotherapy. We tested whether ERCC1 mRNA expression correlates with KRAS and BRAF mutation status in patients with colorectal, pancreatic, and lung cancer. Methods: Formalin fixed paraffin embedded tumor specimens from 1,514 patients (573 colorectal; 91 pancreatic; 850 lung) were microdissected; DNA and RNA were extracted. Specifically designed primers and probes were used to detect 7 different base substitutions in codons 12 and 13 of KRAS and the V600E BRAF mutation. ERCC1 mRNA expression levels were measured by quantitative RT-PCR in a CLIA approved laboratory. Results: Mt KRAS tumors had significantly lower ERCC1 mRNA levels relative to wt ...