Nuclear Morphometry and Ki67 Proliferative Marker in Renal Clear Cell Carcinoma

Bachground and purpose: Different grading systems for renal cell carcinoma (RCC) were proposed to assess patients’ outcome. Interobserver variability interfere with the widespread acceptance. Study of the tumor proliferative activity could provide another parameter for predicting biologic aggression and subsequent prognosis. Patients and Methods: Twenty patients who underwent radical nephrectomy for RCC were selected for histopathologic study. Normal tissue beneath the neoplasm in 5 specimen was used as control. Nuclear morphometry was carried by using CAS 200 image analysis system. Cellular proliferation was examined by immunohistochemistry, using Ki67 (MIB-1) monoclonal antibody on paraffin embedded tissue. All data were subjected to statistical evaluation. Results: The mean nuclear area was significantly increased versus normal nuclei (p = 0.0001). It was significant in relation to patients’ survival. There was significant increased nuclear area with advancing stages (means = 51.85±14.3 μm2, 75.50±12.8 μm2 and 116.35±7.16 μm2) and grade III tumors (mean = 116.27±7.08 μm2). There was an insignificant difference between grades I and II (59.96±17.16 μm2 and 62.34±20.22 μm2 respectively). The mean nuclear diameter was significantly increased with stage IIIa while no difference was noticed between stage I and II (20.29±0.92 μm, 14.31±2.44 μm and 15.33±1.54 μm respectively). Tumor grading was significant in relation to the mean nuclear diameter (14.3±2.44 μm, 15.33±1.45 μm and 20.29±0.92 μm). The mean Ki67 (MIB1) proliferative index (PI) was significantly increased in the tumor versus control region (p = 0.0001). Ki67 PI was significant in relation to stage (9.2±8.89%, 45.98±4.43% and 58.67±6.23%), (p = 0.0001). However, PI was significantly increased with grade III tumors without a significant difference between grade I and II (p = 0.02). Conclusion: Morphometric nuclear area and Ki67 proliferation index could provide reliable information that complements the other parameter to assess tumor prognosis and patients’ survival.