Purpose: This study was designed to detect the expression of epidermal growth factor receptor (EGFR) in tumor specimens of patients with colorectal cancer (CRC); moreover, the relationship between EGFR expression and clinical factors as well as prognosis were analyzed to provide a basis for individualized treatment of CRC.
Methods: This study used paraffin-embedded tumor specimens of 70 CRC patients who were treated with cetuximab. Immunohistochemistry (IHC) was used to detect the expression of EGFR in CRC tumor specimens. The patient clinical features and treatment administered were recorded and then, the therapeutic effect of cetuximab was evaluated. Progression-free survival (PFS) and overall survival (OS) were assessed.
Results: The positive expression rate of EGFR was 64% (45/70), while 18 patients had negative expression. Twenty-two cases had weak positive expression, 15 cases positive expression and another 15 strongly positive expression. Of 70 specimens, 27 (38.6%) had high EGFR expression belonging to 20 (50%) males and 7 (23%) females (p<0.05). However, age, Karnofsky performance status (KPS), tumor site, grade of differentiation and clinical stage showed no significant difference in relation to EGFR expression (p>0.05). No patient achieved complete remission (CR), 15 (21.4%) had partial remission (PR), 12 (17.1%) were in stable state (SD) and 40 (57.1%) patients had disease progression (PD). Disease control rate (DCR) was 39.02% (16/41) in the group with low EGFR expression and 48.28% (14/29) in the group with high EGFR expression (p>0.05).
Conclusion: EGFR expression in CRC tissue is correlated with patient gender. In the group with higher EGFR expression, the effectiveness of cetuximab was significantly higher than that in the low EGFR expression group, indicating correlation between the high expression of EGFR and the short-term effect of cetuximab.