[Expression of lectin binding sites as a prognostic parameter in mouth mucosa carcinomas]

Normal oral mucosa and invasive squamous cell carcinoma of the oral mucosa and the lips were examined immunoenzymatically for different lectin-binding sites and evaluated semiquantitatively. In 110 patients suffering from invasive squamous cell carcinoma of the oral mucosa or the lips, the course of the disease was examined retrospectively with regard to metastases, recurrence and survival time over a minimum of 60 months and was correlated with cell surface binding to lectins (PNA, WGA, UEA I) of the primary tumor. Normal oral mucosa shows intensive cell surface binding to the lectins PNA, WGA and UEA I, but in more than half of the cases the PNA-defined epitopes are blocked by sialic acid.

The comparison of the cumulated survival rates showed a much better prognosis for primary tumors with lectin-binding sites than for those without. Strong and medium WGA-binding pT2 tumors showed significantly better survival rates than those pT2 tumors with poor WGA-binding sites. Carcinomas without lectin binding showed the highest recurrence risk in the course of the disease. In squamous cell carcinomas without WGA and UEA I bindings, the period of time before a relapse occurred was significantly shortened. Carcinomas expressing UEA I-binding sites showed a considerably lower metastasis rate than UEA I-negative tumors. Squamous cell carcinomas with complete sialic acid-blocked PNA-binding sites had the same lymph node metastasis rate as those without expression of PNA-specific disaccharides. A significantly lower metastasis rate than both these groups was exhibited by tumors without or with only partially blocked PNA-binding sites.

In addition to aiding routine grading, the study of PNA-, WGA- and UEA I-binding patterns can therefore provide further information in cases of oral squamous cell carcinoma regarding the potential for metastasis and tumor prognosis.