Selected morphologic features influencing the prognosis of conventional renal cell carcinomas co-expressing P53 and MDM2

Renal cell carcinoma is the most deadly of common urologic malignancies. The classical prognostic factors, including tumor type, grade and stage, as well as performance status of the patient, offer important information, but there is a need for new biomarkers which could improve the quality of prognostication. It has been proposed that tumors co-expressing P53 and MDM2 could represent a specific, more aggressive subgroup. The aim of the study was to explore this hypothesis using tissue microarrays, using two different anti-P53 antibodies. The material analyzed consisted of 470 cases of renal clear cell carcinoma. Reaction for P53 was positive in 15.1 or 13.2% of cases, depending on the antibody used. Reaction for MDM2 was positive in 37.9% of cases; 6.5 or 5.3% of cases coexpressed P53 and MDM2. Both P53-positive and double P53/MDM2-positive cases were higher grade and more likely to contain a sarcomatoid component, but their stage was similar to negative cases. PAb1081 P53-positive MDM2-positive cases were larger than the rest of the tumors (7.6 cm vs. 6.1 cm, p < 0.001). Our data support the hypothesis of prognostic significance of P53, and double P53/MDM2 positivity, yet further studies are needed to clarify the issue.