PROLIFERATION INDEXES - A COMPARISON BETWEEN CUTANEOUS BASAL AND SQUAMOUS-CELL CARCINOMAS

Aims-To compare differences in cell proliferation indexes and apoptoti c indexes between cutaneous basal and squamous cell. carcinomas, in an attempt to suggest an explanation for the differences in their biolog ical behaviour. Methods-Forty cases of cutaneous basal cell carcinoma (BCC) and 40 cases of moderately and well differentiated squamous cell carcinoma (SCC) were retrieved from the archives. Sections, 4 mu m th ick, were cut from formalin fixed, paraffin wax embedded tissue in eac h case and stained with haematoxylin and eosin. These were then examin ed for mitotic and apoptotic figures per 1000 cells. Sections from the same cases were also immunostained with the mouse monoclonal antibody Ki67 (MIB1); positive nuclear staining was counted per 1000 cells. Re sults-No significant differences were found between the mitotic indexe s and apoptotic indexes in these tumours. There was, however, a signif icant difference in Ki67 (MIB1) staining, with greater staining in the squamous cell carcinomas. Conclusion-Estimation of the mitotic and ap optotic indexes did not reveal any differences between these two tumou r types. The proliferation indexes, assessed by Ki67 immunostaining, d id differ. This may be one of the factors underlying the more aggressi ve behaviour of SCC.