Trends in clinical, operative, and pathologic characteristics of surgically treated renal mass in a Korean center: A surgical series from 1988 through 2015

PURPOSE: To analyze trends over a period of 28 years in the clinical, operative, and pathologic characteristics of patients with a renal mass who underwent surgical resection in Korea. MATERIALS AND METHODS: Consecutive patients (n=6,231) with a renal mass who underwent surgical resection at eight Korean institutions between 1988 and 2015 were reviewed. Patients were assigned to one of three groups according to the date of surgery: group 1, 1988–1999; group 2, 2000–2009; and group 3, 2010–2015. RESULTS: Age at the time of surgery, body mass index, smoking status, incidence of diabetes and hypertension, and the number of incidentally identified renal masses increased significantly over time. The proportion of patients undergoing partial nephrectomy (PN) or minimally invasive surgery (MIS) increased sharply during the last two time periods. From 2010, the rate of robot-assisted nephrectomy rose sharply, occurring in 37.8% of MIS cases. Benign pathology was identified in 1.8% and 5.2% of cases in the middle and last periods, respectively; angiomyolipoma was the most common pathology. In later years, tumors were more often localized, although tumor grade increased. Sub-group analysis of small renal masses ≤4 cm revealed similar trends in operative and pathologic characteristics over time. CONCLUSIONS: Between 1988 and 2015, there was a substantial change in the clinical, operative, and histological characteristics of patients who underwent resection of a renal mass in Korea. The most notable changes were stage migration towards localized disease and widespread use of PN and MIS.