Prognostic significance of epidermal growth factor receptor in laryngeal squamous cell carcinoma

Epidermal growth factor receptor (EGFR) content was determined by a radioligand receptor assay in 140 primary laryngeal squamous cell carcinomas (median value of 8.4 fmol mg-1 protein, range 0-169.9 fmol mg-1 protein). Cox univariate regression analysis using EGFR as a continuous variable showed that EGFR levels are directly associated with the risk of death (chi 2 = 14.56, P-value = 0.0001) and relapse (chi 2 = 7.77, P-value = 0.0053). A significant relationship between EGFR status and survival was observed at the different arbitrary cut-off values chosen (8, 16 and 20 fmol mg-1 protein). The cut-off value of 20 fmol mg-1 protein was the best prognostic discriminator. In fact, the 5 year survival was 81% for patients with EGFR- tumours compared with 25% for patients with EGFR+ tumours (P < 0.0001). The 5 year relapse-free survival was 77% for patients with EGFR- tumours compared with 24% for patients with EGFR+ tumours (P < 0.010). When clinicopathological parameters and EGFR status were examined in the multivariate analysis, T classification and EGFR status retained an independent prognostic value. In this study we demonstrated that high EGFR levels single out patients with poor prognosis in laryngeal cancer.