Role of nuclear grading in stage I renal cell carcinoma

Through a retrospective histologic analysis of 55 cases of Stage I renal cell carcinoma, we evaluated the usefulness of the nuclear grading system (Fuhrman, Lasky, Limas) in identifying those tumors that will eventually metastasize and kill the patient. The difference in five-year survival rates between patients with combined nuclear grade 1-3 tumors (n = 50, 91%) and grade 4 tumors (n = 5, 9%) was significant (P less than 0.0046). Other predictors of death due to renal cell carcinoma included: tumor size greater than 8 cm (P less than 0.001) and mitoses greater than one per 10 high-power field (P less than 0.01). Within Stage I tumors, therefore, nuclear grade is an important morphologic variable for predicting long-term survival. Identification of nuclear grade 4 neoplasms may become prognostically indispensable to determine the metastatic potential of early-stage tumors and thereby to institute appropriate systemic therapy.