RESUMO
BACKGROUND: Limitations of current diagnotic techniques may allow some patients with presumed renal cell carcinoma (RCC) to undergo nephrectomy without definitive confirmation of malignancy. OBJECTIVES: To confirm previous estimates of postnephrectomy renal mass diagnosis and to assess the economic impact of nephrectomy. METHODS: This retrospective cohort analysis identified commercial enrollees who underwent nephrectomy with a diagnosis of RCC between July 1, 2000, and March 30, 2008. Study subjects were stratified based on medical claims for benign or malignant disease after the nephrectomy date. Cohorts were compared on resource utilization before and after nephrectomy, occurrence of postsurgical complications, and associated 1-year costs of care. RESULTS: Of 10,404 patients undergoing nephrectomy for presumed RCC, 1613 (15.5%) were subsequently identified as having benign disease, despite median presurgical diagnostic expenditures of $1311 per patient (interquartile range [IQR], $467-$2606). Median expenditures for the 12 months postnephrectomy were $26,920 per patient (IQR, $16,851-$46,982) for those with malignant disease and $23,951 per patient (IQR, $14,873-$38,190) for those with benign disease (P<.0001). For patients with benign disease, 17.5% experienced a postsurgical adverse event, resulting in a 1.5-fold increase in expenditures (median $31,838 per patient for those with event vs $22,770 per patient for those without event; P<.0001). CONCLUSIONS: In this study, approximately 1 in 6 patients were found to have a benign renal mass postnephrectomy. Given the risk of surgical complications and related economic consequences, methods for better identifying malignant versus benign disease prior to surgery could provide significant benefits to patients and payers.