Clinical impact of the presence of the worst nucleolar grade in renal cell carcinoma specimens

Objective: Renal cell carcinoma (RCC) with a high-nucleolar-grade component is considered to be an aggressive type of tumor. In the present study, we evaluated the impact of the presence of the worst-nucleolar-grade component and also tried to determine predictors for recurrence and prognosis in patients with the worst grade component. Methods: We evaluated 314 patients with RCC. A three-graded system was used for nucleolar grading, the patients were classified into four groups according to the presence of the worst nucleolar grade (Grade 3) and the occupancy of each grade, and clinicopathological factors and clinical outcomes were compared. In patients of Grade 3 components (Groups 1 and 2), factors influencing on prognosis and recurrence were evaluated by multivariate analysis. Results: There was no significant difference in clinicopathological factors between Group 1 (with Grade 3-dominant tumors) and Group 2 (with tumors in which Grade 1 or 2 was dominant and there were Grade 3 components). Neither did cause-specific survival or recurrence-free survival differ significantly between those two groups. In multivariate analysis, only distant metastasis was an independent predictor for prognosis in all patients with Grade 3 components. Moreover, an elevated C-reactive protein (CRP) level (≥1 mg/dl) was the only independent predictor of recurrence in NOMO patients. Conclusions: Regardless of dominancy, the presence of the worst grade component has a significant clinical impact in RCC patients. NOMO patients whose RCC has worst-grade components but whose CRP levels are <1 are expected to have longer recurrence-free intervals and to survive longer than those whose CRP levels are higher.