PROGNOSTIC INFLUENCE OF p53 EXPRESSION IN GASTRIC CANCER

The presence of the nuclear phosphoprotein p53 was investigated in a series of 120 consecutive gastric carcinomas. This immunohistochemical study on formalin-fixed, paraffin-embedded material found p53 expression in 43 per cent ( n =51) of carcinomas using a monoclonal antibody (DO-1), whereas no immunoreactivity for p53 was present in tumour-associated non-neoplastic gastric mucosa or tumour stroma. There was no statistically significant correlation with known prognostic parameters such as extent of tumour growth (pT state), nodal involvement (pN state), or tumour grade. The same applied for association with patient age and sex or pathological parameters such as tumour size, localization, or growth pattern according to histological classification. Kaplan–Meier analysis revealed marginal statistically significant differences in survival times between patients with p53-positive tumours with more than 35 per cent of p53-positive tumour cells and those with less than 35 per cent of p53-positive tumour cells or p53-negative tumours ( P =0·04). However, by multivariate analysis, p53 immunoreactivity did not turn out as an independent prognostic parameter. p53 expression can easily be detected in a variety of human malignancies including gastric cancer by immunohistochemical methods, but its prognostic significance and possible role as an independent marker of poor prognosis still have to be confirmed by further studies.