DECREASING P53 OVEREXPRESSION IN SEQUENTIAL, RECUR RENT, ORAL SQUAMOUS-CELL CARCINOMAS

Expression of abnormal p53 protein is a widely recognised marker of ma lignancy including oral squamous cell carcinoma, This is a longitudina l study of p53 expression in fixed, paraffin-embedded tissue from 3 pa tients with multiple, recurrent, squamous cell carcinomas of floor of mouth (n = 4, 4, 3), All carcinomas demonstrated increased expression of p53 compared to normal tissues, However, there was reduction in exp ression from primaries to subsequent recurrent tumours in all 3 patien ts, The significance of reduction of expression of p53 in sequential r ecurrences is unclear, but as each of these patients has now survived for at least 5 years this may be a phenomenon indicating a favourable prognosis, As this study relates to only 3 patients, a larger study is needed to confirm this initial observation.