Overexpression of EGFR and TGF-α as Prognostic Indicators in Laryngeal Carcinoma

Abstract

Expressions of epidermal growth factor receptor (EGFR) and one of its ligands, transforming growth factor-α (TGF-α), were determined immunohistochemically in 49 laryngeal squamous cell carcinomas.
Overexpression rates of EGFR and TGF-a were 38.8% and 55.1% respectively, without significant difference due to age, lymphnode status, location of tumor or grade of cancer tissues.
The survival rate was significantly lower in patients with EGFR(+) than in those with EGFR(-) (P<0.05). Patients with TGF-α(+) also showed a lower survival rate than those with TGF-α(-). However, recurrence rates were significantly higher in patients with EGFR(+) and TGF-α(+) than in those with EGFR(-) and TGF-α(-) (P<0.05, both). Futhermore, according to the staining status of the two immunological factors, four subgroups were classified: A: E(-)/T(-), B: E(+)/T(-), C: E(-)/T(+), D: E(+)/T(+). Both the survival rate and the recurrence rate of patients in the “D-subgroup” were the worst, with significant differences noted. Since the overexpression rates of the two factors increased with stage, further analyse were separately demonstrated in stage I, II and stage III, IV. In stage I, II,6 of 16 cases developed recurrence after radiation treatment, in which,5 cases were TGF-α(+) and 1 case was TGF-α(-), but for EGFR, this trend did not appear; in stage III,IV, survival rates in patients with EGFR(-) and TGF-α(-) were 91% and 100%. However, for those with EGFR(+) and TGF-α(+), these ra tes declined to 40% and 56%, respectively. These results also showed significant differences (P<0.05, both).
As a whole, the results suggested that TGF-a may act as an autocrine growth factor through overexpression of EGFR, and overexpression of both EGFR and TGF-a can be used as valuable prognostic indicators for patients with laryngeal squamous cell carcinoma.