EGFR expression in gallbladder carcinoma in North America

Increased epidermal growth factor receptor (EGF receptor) expression has been noted in various cancers and has become a useful target for therapeutic interventions. Small studies from Asia and Australia have demonstrated EGFR over-expression in gallbladder cancer. We sought to evaluate the expression of EGFR in a series of 16 gallbladder cancer patients from North America.

Using tumor registry data, we identified 16 patients diagnosed with gall bladder carcinoma at our medical center between the years of 1998 and 2005. We performed a retrospective review of these patients' charts, obtained cell blocks from pathology archives and stained for EGFR and Her2/neu.

Fifteen of sixteen patients were noted to over-express EGFR. Three were determined 1+, nine were 2+ and three were 3+. Eight patients had poorly differentiated adenocarcinoma, six had moderately differentiated and two had well-differentiated tumors. In this small series, there was a trend toward shorter survival and more poorly differentiated tumors in patients with greater intensity of EGFR expression. One patient was EGFR negative but 3+ for erb-2/Her 2-neu expression. No patient co-expressed EGFR and Her-2-neu. Median survival of patients in this series was 17 months.

In view of our observations confirming the over-expression of EGFR in our patient population in North America, and the recent success of EGFR targeted therapies in other solid tumors that over-express EGFR, it may now be appropriate to evaluate agents targeting this pathway either as single agents or in combination with standard chemotherapy.