Prognostic value of histological and biological markers in pharyngeal squamous cell carcinoma: a case-control study.

Between 1980 and 1985, 914 patients with head and neck squamous cell carcinoma underwent lymph node dissection in our institution. The prognostic value of clinical factors has already been reported (Mamelle et al, 1994, Am J Surg 168: 494-498). We present here a comparison of biological characteristics of pharyngeal tumours in patients who developed distant metastasis and in patients without metastasis, matched on tumour site, node site and size, and year of diagnosis. Tumour differentiation, keratinization, vascular emboli, immunohistochemical expression of p53, c-erb-B2, Rb and bcl2 were first assessed in 31 pairs of patients. Factors of potential interest were then determined in 32 additional pairs of patients. Statistical analysis showed that the risk of distant metastasis was halved in patients with tumours expressing c-erb-B2 compared with patients with c-erb-B2-negative tumours (P = 0.05). The significance of c-erb-B2 expression and its potential value as a prognostic factor is discussed.