Differential expression of prognostic markers in histological subtypes of papillary renal cell carcinoma

OBJECTIVE To assess the expression of the tumour markers stromelysin 3, MUC1, p53 and cytokeratin-7 in papillary renal cell carcinoma (pRCC, for which two histological subtypes are distinguished, i.e. type 1 and type 2, the latter appearing to be associated with a poorer prognosis) and to determine whether any of these markers might be of prognostic value. PATIENTS AND METHODS In a retrospective study of 50 patients, the type and nuclear grade of tumours was determined by histological analyses, the presence of microvascular emboli detected, and the markers assessed by immunohistochemical analysis using anti-stromelysin 3, anti-MUC1, anti-p53 and anti-cytokeratin-7 antibodies. RESULTS Twenty-five patients each had a type 1 or type 2 tumour. MUC1 and cytokeratin-7 were principally expressed in type 1 tumours, being detected in 76% and 84%, respectively. By contrast, p53 accumulated principally in type 2 tumours (36%); the accumulation of p53 was also associated with poorer survival. In patients with type 2 tumours with a more unfavourable development, stromelysin-3 expression was associated with a more advanced stage and a higher risk of metastases. CONCLUSION Subtyping pRCC according to the recommended morphological criteria appears to be worthwhile, and can be reinforced by immunohistochemical tests capable of detecting cytokeratin-7 and MUC1 expression. Immunohistochemical detection of p53 is of prognostic value, as accumulation of this factor is associated with poorer survival.