K. E. Zorn1, W. P. Christensen1, V. Margulis3, T. M. Bauman1, C. G. Wood2, E. J. Abel1 1University Of Wisconsin,Urology,Madison, WI, USA 2University Of Texas MD Anderson Cancer Center,Urology,Houston, TX, USA 3University Of Texas Southwestern Medical Center,Urology,Dallas, TX, USA
Introduction: In approximately 10% of renal cell carcinoma (RCC) patients, tumor extends beyond the kidney into the venous system, increasing the risk of postoperative recurrence. Anemia is known to predict worse survival in patients with metastatic RCC, but the prognostic ability of preoperative anemia has not been studied in non-metastatic high risk RCC patients. The purpose of this study was to evaluate whether patients with preoperative anemia had worse postoperative cancer outcomes using a multi-institutional contemporary series of non-metastatic RCC patients with venous involvement.
Methods: A comprehensive review of clinical and pathological risk factors was performed for consecutive RCC patients with thrombus treated between 2000 and 2012 at three separate institutions. Univariate and multivariate Cox proportional hazards analysis was used to evaluate association of anemia or other common risk factors for cancer specific survival (CSS) and recurrence free survival (RFS).
Results: A total of 470 non-metastatic patients were treated surgically for RCC with venous thrombus invasion from 2000-2012 at participating centers. Thrombus extended into the renal vein in 259 (55.1%) patients, into the IVC <2cm in 65 (13.8%) patients, into the IVC >2cm but below hepatic veins in 81 (17.2%) patients, and within the IVC above the hepatic veins in 65 (13.8%) patients.
Median follow-up was 28.4 months (IQR 12.2-54.9) and 188 (40.0%) patients developed recurrent disease within the follow-up period. Of patients that developed recurrent disease, initial site of recurrent disease was solitary for 128 (68.1%) patients while 60 (31.9%) patients presented initially with multiple sites of metastatic disease. Preoperative hemoglobin was independently predictive of recurrence with a hazard ratio of 1.727 (95% CI: 1.251-2.385, p=0.0009). Other independent predictors of recurrence included BMI ≤20, perinephric fat invasion by tumor, non-clear cell histology and tumor width.
Median CSS was 136.6 (IQR 43.8-NR) months and 112 (23.8%) patients died of RCC within the follow-up period. BMI, systemic symptoms, IVC thrombus level above the hepatic veins, and estimated blood loss were associated with CSS on univariate analysis. On multivariate analysis, only preoperative hemoglobin less than lower limit of normal (HR 2.051, p=0.02) and tumor width per cm (HR 1.078, p=0.02) were independently predictive of CSS.
Conclusion: In non-metastatic RCC patients with venous invasion, preoperative anemia and tumor diameter were independent predictors of recurrence and cancer mortality.
