Expression of the cell-cell adhesion molecule E-cadherin in tongue carcinoma cell lines.

A reduction in cell adhesiveness and cell invasion are essential steps in tumour progression. In the present study six tongue carcinoma cell lines were compared with regard to their invasive potential in two in vitro invasion assay systems and for their patterns of expression of the cell-cell adhesion molecule E-cadherin. The three cell lines negative for E-cadherin expression were invasive in both assays. One cell line with strong E-cadherin expression was strongly invasive and one weakly invasive. One cell line with reduced E-cadherin expression was weakly invasive. There was no significant pattern to these findings (chi 2 = 0.375; p = 0.54). This supports previous studies from this group that suggest that E-cadherin is only one of the presumably many molecules involved in tumour progression in squamous cell carcinoma of the tongue.

Has the cellular proliferation marker Ki67 any clinical relevance in squamous cell carcinoma of the head and neck?

Over the years many laboratory factors have been studied with a view to predicting the course of head and neck cancer. The lack of success prompted the application of various measures of cell kinetics to this topic. The present study includes 79 patients with a proven squamous cell carcinoma of the head and neck at various sites and having various treatments. Ki67 staining was carried out using the avidin-biotin complex method and counts recorded per 1000 tumour cells. The patients' mean age was 61 years and the 5 year survival was 54% (95% CI, 29-73%). The median Ki67 index was 278 representing the number of cells stained positively per 1000 tumour cells. The minimum staining was 82 and the maximum 808 with a lower quartile of 95 and an upper quartile of 452. The Ki67 index failed to correlate with any host or tumour factors. In addition, median Ki67 values were not significantly different between irradiated tissue and non-irradiated tissue, between sites nor between patients who did and did not later develop lymph-node metastases. Of particular relevance is that Ki67 value did not correlate with survival. Data was further analysed using Cox's proportional hazards model for survival. Ki67 had no significant effect on survival. It is concluded that Ki67 index is of no value in predicting the course of squamous cell carcinoma of the head and neck.

Expression of the cell-cell adhesion molecule E-cadherin in squamous cell carcinoma of the head and neck.

The expression of the cell-cell adhesion molecule E-cadherin has previously been shown to be reduced in poorly differentiated squamous cell carcinoma of the head and neck and absent in nodal metastases. Twenty-eight patients with previously untreated squamous cell carcinoma of the head and neck, 22 of whom had nodal metastases at presentation, were investigated for E-cadherin expression using the monoclonal antibody 6F9, specific for human E-cadherin. Reduced expression was seen in the poorly differentiated primary tumours, compared with well differentiated tumours, but this trend was not statistically significant. E-cadherin expression was present at a reduced level in nodal metastases. It was also noted that, where both the primary tumour and corresponding nodal metastasis were investigated, E-cadherin expression was identical for both samples. The degree of E-cadherin expression did not correlate with survival. These data confirm a reduction in E-cadherin expression in poorly differentiated tumours. There was no correlation between E-cadherin expression and any of the host, tumour and treatment factors associated with malignancies of the head and neck region.