RADIOTHERAPY FOR ESOPHAGUS CARCINOMA - THE IMPACT OF P53 ON TREATMENTOUTCOME

Background and purpose: Wildtype p53 protein plays an important role i n the cellular response to ionizing radiation and other DNA damaging a gents and is mutated in many human tumours, We evaluated the relations hip of the immunohistochemically determined p53 protein status and the disease control with radiotherapy alone for carcinoma of the oesophag us. Materials and methods: Immunostaining for p53 protein was performe d on paraffin-embedded specimens from 69 patients with adeno- and squa mous cell carcinoma of the oesophagus, All patients were treated by ra diotherapy exclusively, consisting of a combination of external irradi ation and intraluminal brachytherapy, using two different dose levels. Results: Fifty-four percent (37/69) of the rumours showed overexpress ion of the p53 protein. No difference in pre-treatment parameters for p53-positive and p53-negative cases was detected. In multivariate anal ysis p53 was significantly associated with overall survival (OS) next to weight loss, tumour stage and N-stage. For metastatic-free survival (MFS) p53 status proved to be the sole independent prognostic factor. The influence of p53 on local recurrence-free survival (LRFS), howeve r, was not as strong as on OS and MFS, Conclusions: Immunohistochemica lly detected overexpression of mutated p53 protein in oesophagus carci noma was an independent prognostic factor in a group of patients treat ed with radiotherapy alone. (C) 1998 Elsevier Science Ireland Ltd.