Epidermal growth factor receptor expression in stage II-III colon carcinoma: A preliminary study

9718 Background: Epidermal growth factor receptor (EGFR) is a protoncogen that is found overexpressed in colorectal carcinomas (CRC) and it correlates with a worse prognosis. The aim was to describe EGFR overexpression patterns in non-metastatic CRC and to correlate these data with follow-up. Methods: We analyzed a series of 56 CRC. Inclusion criteria were: a) resected primary adenocarcinoma; b) curative surgery; c) pT3 N0–2 M0 without progression during the first 6 months post surgery; d) minimum follow-up over 3 years. EGFR overexpression was analyzed by immunohistochemistry (IHC) using the Dako PharmaDx kit (Glostrup, Denmark). As positive control the Dako slides and a bloc cell of A431-AAM cells were used. Presence of cytoplasmic and membrane patterns (intensity 1(+), 2(+) and 3(+)) were evaluated as well as the percentage of positive cells. Statistical analysis: association between qualitative variables was analyzed by Fisher's exact test. Disease-free and overall survival distributions were estimated by the Kaplan-Meier method and were analyzed with the log rank test. All P values are from two-sided statistical tests. Results: Characteristics of the patients (pts) were as follows: mean age: 68,4 years (range: 28–91); sex: 24 male and 32 female; location: 19 right colon and 37 left colon; follow-up: 44 pts alive without disease (78,5%), 9 died of disease (16,5%) and 3 died of other causes (5%). 10 pts had metastasis in the follow-up. IHC: Forty-two cases were positive (75%) and were classified as follows: 17 with >50% of positive cells (30%), 7 with 25–50% of positive cells (13%) and 18 cases with < 25% of positive cells. Patterns of staining were cytoplasmic predominance in 27 cases (48%) and 15 with membrane predominance (27%): 4 with intensity 1(+), 9 with 2(+) and 2 with 3(+). Only those patients with tumors harboring membrane positivity 2(+) and 3(+) had more probability to present metastasis (p= 0.067). Conclusions: EGFR overexpression evaluated as a membrane pattern with 2(+) and 3(+) intensity is related with metastatic development in colon carcinoma. Suported by a grant of C.I.R. Hospital de Sabadell. Consorci Sanitari Parc Taulí. Sabadell. Spain No significant financial relationships to disclose.