Prognostic impact of epidermal growth factor receptor on clear cell renal cell carcinoma: Does it change with different expression patterns?

Introduction: The aim of this study was to assess whether epidermal growth factor receptor (EGFR) overexpression was a significant prognostic factor in clear cell renal cell carcinoma (CRCC) and whether its prognostic significance was affected by immunohistochemical expression patterns.

Materials And Methods: Immunohistochemistry was performed on 100 cases of CRCC using an antibody against EGFR. Tumors were grouped by nuclear grade (NG) as low-NG (NG1, 2) or high NG (NG3, 4), and by pathological stage as localized (pT1, 2), or locally invasive (pT3, 4). Clinical disease was grouped by clinical stage as early stage (stage I, II), or late stage (stage III, IV). Evaluation of the EGFR overexpression was based on cytoplasmic (EGFR Cyt), and membranous (EGFR Mem) staining.

Results: EGFR Cyt correlated with high NG (P = 0.001), lymphovascular invasion (P = 0.028), regional lymph node involvement (P = 0.027), metastasis (P = 0.001), late stage (P = 0.003), cancer-specific death (P = 0.036), and was a predictor for disease-specific survival (P = 0.012) whereas EGFR Mem correlated with only local invasion (P = 0.021) and perirenal invasion (P = 0.009) and did not show any correlation with cancer-specific death or disease specific survival.

Conclusion: Our findings suggest that EGFR overexpression is an important prognostic factor in CRCC, and its prognostic value differs significantly with respect to the location of EGFR immunostaining. This prognostic difference may give direction on the management and treatment of CRCC patients.