Ki67 is an independent predictor of oncological outcomes in patients with localized clear-cell renal cell carcinoma
Menée sur 401 patients atteints d'un carcinome rénal à cellules claires de stade localisé et traités par néphrectomie radicale ou partielle (âge : 17 à 85 ans ; durée médiane de suivi : 22 mois), cette étude montre que le niveau d'expression tumorale de Ki67 peut, indépendamment des autres facteurs, prédire la survie des patients
Objective : To validate the impact of Ki67 expression on oncological outcomes of patients treated for clinically localized clear-cell renal cell carcinoma (ccRCC).
Patients and Methods : Immunohistochemistry for Ki67 was performed on tissue microarray constructs of patients treated with radical or partial nephrectomy for clinically localized (M0) ccRCC and Ki67 expression >10% was considered abnormal. Clinical and pathological data elements were entered into an institutional review board-approved database. The Kaplan–Meier method and Cox regression models were used to analyse disease-free survival (DFS) and cancer-specific survival (CSS) probabilities.
Results : Of 401 patients, 59.6% were males. The median (range) age was 58 (17–85) years, follow-up was 22 (0–150) months and time to death was 27 (0–150) months. A total of 20.2% of patients had advanced stage (pT3–T4) and 31% had advanced grade (3–4) disease. Abnormal expression of Ki67 was seen in 6.5% of our cohort and was associated with adverse pathological features (P < 0.05). Patients with high expression of Ki67 were found to have 5-year DFS and CSS rates of 67 and 84%, respectively, vs 87 and 95%, respectively, in those with normal expression (P < 0.001 and P < 0.05, respectively). In multivariable analyses, adjusting for stage and grade, abnormal Ki67 expression was an independent predictor of DFS (hazard ratio [HR] 3.77, P = 0.011, 95% confidence interval [CI] 1.35–10.52), but not of CSS (HR 3.51 P = 0.137, 95% CI 0.671–18.35).
Conclusions : Our findings support the role of Ki67 as a powerful independent predictor of inferior oncological outcomes in patients with ccRCC. Further prospective studies are needed to determine the clinical applicability of these findings.
BJU International , résumé, 2012