Histopathologic prognostic indicators for renal cell carcinoma.

Assessment of prognostic markers for renal cell carcinoma (RCC) has produced varying and often conflicting results. There is evidence to indicate that tumor stage is significantly associated with outcome, with extrarenal tumor spread being correlated with poor patient survival. The significance of other staging categories is debated, and the predictive value of tumor size for localized tumors, and infiltration of the renal vein and inferior vena cava is less certain. Numerous studies have investigated the association of tumor grade, based on nuclear or a combination of nuclear and cytoplasmic characteristics, with patient survival for RCC. There is substantial agreement that tumors of high nuclear grade and those with sarcomatoid differentiation are associated with poor patient outcome, whereas the predictive nature of other grading categories is debated. In particular, there is growing evidence to show that in four division grading systems, the upper two grading categories have similar survivals. Of other prognostic parameters tested in various prospective and retrospective studies only assessment of tumor proliferation markers (silver-staining nucleolar organizer regions, proliferating cell nuclear antigen, and Ki-67 antigen) have shown any consistency of association with survival. Tumor angiogenesis, nuclear morphometry, tumor suppressor gene, and growth factor expression have, in some studies, been correlated with survival for patients with RCC; however, contrary findings have been reported, and there is no consensus on the prognostic significance of these parameters for RCC.