Approximately one in six patients who had their kidneys removed due to renal cell carcinoma were later found to have a benign renal mass, underscoring the challenge diagnostic imaging faces in distinguishing between benign and malignant renal tumors, according to a study published Aug. 12 in the American Journal of Managed Care.

Increasing use of cross-sectional imaging for nonspecific abdominal complaints has increased early detection of renal cell carcinomas, with more than 70 percent of kidney cancers now being found incidentally at sizes less than 7 cm, according to Aviva G. Asnis-Alibozek, PA-C, of IBA Molecular, Dulles, Va., and colleagues.

Increased incidental findings, however, can also lead to more unnecessarily aggressive treatments, such as radical nephrectomy for benign tumors. Based on the results of the study, more than 10,000 potentially avoidable nephrectomies may be performed annually in the U.S.

“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,” wrote the authors.

To assess the economic impact of kidney removal in the management of renal masses, Asnis-Alibozek and colleagues retrospectively analyzed a cohort of commercial enrollees who underwent nephrectomy based on a diagnosis of renal cell carcinoma between July 1, 2000, and March 30, 2008.

Of the 10,404 patients included in the study, 15.5 percent were subsequently identified as having benign disease, reported the authors.

Median pre-surgical diagnostic expenditures totaled $1,311 per patient, as more than 90 percent underwent at least one diagnostic procedure, most often a CT scan. “Furthermore, we found that approximately one-third of patients underwent two or more CT scans in the preoperative period, suggesting redundant and possibly inefficient use of diagnostic imaging,” wrote the authors. 

Median expenditures for the year following nephrectomy were $26,920 per patient for those with malignant disease, and $23,951 per patient for those who were revealed to have benign disease. Costs varied considerably as a result of postsurgical adverse events, which occurred in 17.5 percent of patients with benign disease. Expenditures in these cases were nearly 50 percent higher than in cases of benign disease where there were no such events following nephrectomy.

“While administrative claims data did not allow for confirmation of the diagnosis nor the necessity for the original nephrectomy, these results reveal that a substantial number of patients might have been spared the inherent morbidity and cost of surgery and postoperative care had better preoperative characterization of their tumor been available,” wrote Asnis-Alibozek and colleagues.

Since the current study was focused on economic impacts of potential surgical overtreatment, the authors called for further research into the effect that current preoperative diagnostic accuracy and subsequent management of renal tumors has on patients’ health-related quality of life.