Abstract
BACKGROUND: Microscopic hematuria is associated with various urinary system diseases and is commonly used for the diagnosis of these conditions. Its prognostic role in non-metastatic renal cell carcinoma (RCC) patients who underwent nephrectomy remains unclear. PATIENTS AND METHODS: A retrospective analysis of non-metastatic RCC patients who underwent nephrectomy in West China Hospital of Sichuan University from 2011 to 2013 was performed. Significant microscopic hematuria (SMH), defined as a threshold with a significant impact on disease-free survival (DFS) and overall survival (OS), was determined by Kaplan-Meier curves and the Maximally Selected Log-Rank Statistic. Kaplan-Meier curves were then used to estimate patients' DFS and OS, and the log-rank test was used to examine statistical significance. Logistic regression was utilized to identify clinical-pathological factors associated with SMH, while Cox regression was employed to determine independent factors of survival. RESULTS: A total of 773 patients were included, and 20 red blood cells per high-power field was identified as the cutoff of SMH, of which 90 patients had preoperative SMH (11.6%) and 683 patients (88.4%) did not. Larger tumor size (OR = 1.10 [per cm], 95% CI 1.01-1.19, p = 0.036) and higher Fuhrman grade (grade 3 vs. grade 1-2, OR = 1.76, 95% CI 1.09-2.83, p = 0.02; grade 4 vs. grade 1-2, OR = 2.15, 95% CI 0.73-6.31, p = 0.164) were predictors of SMH. Compared to non-SMH patients, SMH patients had poorer DFS (HR = 3.16, 95% CI 2.07-4.83, p < 0.001) and OS (HR = 2.11, 95% CI 1.34-3.32, p = 0.001). CONCLUSION: In summary, preoperative SMH is associated with larger tumor size and higher Fuhrman grade, and it is also independently correlated with poorer DFS and OS in non-metastatic RCC patients who underwent nephrectomy.