Collagen IV and Tenascin Immunoreactivity as Prognostic Determinant in Benign and Malignant Salivary Gland Tumours

Abstract

The expression of collagen IV and tenascin was studied in a series of 219 salivary gland tumours with special emphasis on the prognostic significance of these extracellular matrix constituents. Continuous and uninterrupted staining of the basal membrane with collagen IV antibody was found in 62% (64/103) of the carcinomas and in 92% (107/116) of the benign tumours, the staining being weak and interrupted in 38% (39/103) and 8% (9/116) of cases, respectively. Weak immunoreactivity for collagen IV was significantly (p=0.05) associated with recurrences of the malignant salivary gland tumours. Intense collagen IV staining of the basal membrane was more frequent (35.9%) in patients who were alive, as compared with that (19.4%) of the patients who died of salivary gland cancer (p=0.03). Similarly, the intactness of the basal membrane was directly related to patient survival. In benign tumours, no such differences were found. In multivariate analysis, collagen IV immunoreactivity was related to the age of the patients (p=0.007) and to tumour diameter > 4.0 cm (p=0.005). Intense tenascin immunoreactivity was found in 45% (46/103) of the carcinomas and in 43% (50/116) of the benign tumours, 55% (57/103) and 57% (66/116) of the cases being entirely tenascin-negative, respectively. Tenascin immunoreactivity was not related to the clinical behaviour of malignant salivary gland tumours. In benign tumours, an intense staining for tenascin was a determinant of recurrent disease (p=0.05). In multivariate analysis, tenascin immunoreactivity was intimately associated with erbB-2 positivity (p=0.03) and weak staining of collagen IV (p=0.02). The results suggest that immunostaining of collagen IV (but not that of tenascin) is of prognostic value in malignant salivary gland tumours.

Key Words:

• collagen IV
• tenascin
• salivary gland tumours
• prognosis