Purpose: High expression levels of EGFR mRNA are reported to be associated with a higher response probability in epidermal growth factor receptor (EGFR) targeted drugs. Our aim was to determine how EGFR gene expression levels in primary colorectal cancer (CRC) were related to those in liver metastases.
Methods: 31 pairs of primary CRC and corresponding liver metastases were analyzed. Gene expression level was measured using real-time RT-PCR.
Results: No significant difference was observed between median mRNA expression levels of EGFR in primary cancer and those in corresponding liver metastases (P = 0.99). When matched tissue sets were compared on an individual basis, there was a significant correlation for EGFR mRNA expression between primary cancer and corresponding liver metastases (rs = 0.78, P < 0.0001).
Conclusions: A good prediction of EGFR mRNA levels in liver metastases can be obtained by measuring those in the primary CRC.