HER family receptors expression in squamous cell carcinoma of the tongue: study of the possible prognostic and biological significance.

OBJECTIVES

The squamous cell carcinoma of the tongue (SCCT) is biologically and epidemiologically distinct from other oral cavity cancers and is associated with lower overall survival rates. The role of HER family members (HER-1, HER-2/neu, HER-3 and HER-4) in the pathogenesis and progression of head and neck squamous cell carcinomas has been demonstrated but no report have focused on SCCT. This study investigated, the expression of all members of the HER family, in a series of SCCT and studied the possible prognostic value and correlation with various clinico-pathological parameters.

METHODS

HER-1, HER-2/neu, HER-3 and HER-4 expression was analysed by semi-quantitative immunohistochemical staining on paraffin embedded tissue specimens from 40 patients who underwent surgery for SCCT between 1996 and 2006.

RESULTS

HER-1 was overexpressed in 26 cases (65%), HER-2/neu in two (5%), HER-3 in 19 (48%) and HER-4 in three cases (8%). No significant correlation was found between clinicopathological variables and expression of HER-1 and HER-2/neu. HER-3 overexpression was significantly related to nodal stage, age (>or=64 years) and decreased overall survival (P <or= 0.05). HER-4 overexpression was significantly associated with low histological grade including when it was coexpressed with HER-3 but in this case the prognosis was worse (P < 0.05).

CONCLUSIONS

These results suggest that HER-1 and HER-2/neu when determined with stringent criteria are not useful indicators of prognosis in SCCT. Only HER-3 overexpression may help in identifying SCCT with greater malignant potential also when it is coexpressed with HER-4. Instead, as in other malignancies, HER-4 could play a protective role in SCCT.