National trends and economic impact of surgical treatment for benign kidney tumors.

OBJECTIVES: Kidney masses suspicious for malignancy are frequently detected by cross-sectional imaging; however, little is known about the burden of surgical treatment for tumors found to be benign following excision. MATERIAL AND METHODS: We queried the National Inpatient Sample to identify records of individuals who received surgical treatment for renal neoplasms between 2004 and 2014. We characterized temporal treatment trends, patient demographics, treatment related complications, and charges. RESULTS: We identified 7,099 (8.5%) and 76,892 (91.5%) patients who were treated for benign and malignant tumors, respectively. Benign masses accounted for 14.8% of partial and 5.5% of radical nephrectomies. The rates of surgery for benign tumors have remained steady (P = 0.058). The frequency of inpatient death was higher in those with malignant disease (0.63% vs. 0.18%, P < 0.0001). Median length of stay was longer for individuals with malignant renal tumors (4.86 vs. 4.12 days, P < 0.0001). The total discharge bill adjusting for inflation for benign or malignant renal surgery increased each year (R2 = 0.428, R2 = 0.719, P = 0.001, P = 0.0311, respectively). As of 2014, the estimated national inpatient cost of management for benign renal tumors was $153 million dollars ($55,573/individual). CONCLUSIONS: 8.5% of inpatient renal surgical admissions are performed for benign masses. There has been a trend toward decreased operative management for benign renal tumors over time. Surgical management remains a significant economic burden. Efforts to prospectively evaluate modalities for pretreatment identification should be further pursued.