NEW ORLEANS – Renal mass biopsy has traditionally played a restricted diagnostic role, but with its improved diagnostic accuracy, it is becoming a viable clinical tool in the modern era, according to Dr. Matthew Maurice.
“We were seeking to understand the current role of biopsy in the management of renal masses, said Dr. Maurice, a urology resident at University Hospitals Case Medical Center in Cleveland. “We used the National Cancer Database and looked at data from 2003 to 2011; what we saw was a rise in renal mass biopsy in the final 3 years of the study. It’s a very small increase, but a statistically significant increase, with people in 2011 having 1.3 times higher odds of being biopsied than they would have had in 2003.”
Dr. Mathew Maurice
Dr. Maurice and his colleagues at Case Medical conducted a study examining renal mass biopsy use in the modern era, and presented their findings in a poster at the annual meeting of the American Urological Association.
Using the National Cancer Database (NCDB), Dr. Maurice and his colleagues identified all patients diagnosed with renal cell carcinoma (RCC) between 2003 and 2011. Patients within the RCC cohort were then classified as having undergone renal biopsy or not. Renal biopsy utilization rates were plotted over time, and patient, disease, provider, and treatment variables were evaluated via univariate and multivariate logistic regression models to determine the predictors of renal biopsy.
Out of 304,583 patients with kidney cancer, 35,942 patients (11.8%) underwent renal mass biopsy. From 2009 to 2011, Dr. Maurice and his coinvestigators observed a significant increase in biopsy use; patients diagnosed with a renal mass in 2011 had 1.3 times higher odds of being biopsied compared with those diagnosed in 2003 (odds radio, 1.3, confidence interval, 1.3-1.4, P < .01).
Eventual treatment was the strongest predictor of biopsy utilization. “Patients receiving observation or thermal ablative therapy (either cryoablation or radiofrequency ablation) were much more likely to receive biopsy than were those who received surgical therapy such as radical or partial nephrectomy,” Dr. Maurice explained. “So it seems like those treatments are driving the use of renal biopsy utilization in contemporary patients.”
Compared to patients treated with partial nephrectomy, patients managed with observation, cryoablation, or radiofrequency ablation had 4.2, 8.0, and 19.1 times the odds of being biopsied, respectively (OR, 4.2, CI, 4.0-4.5, P < .01; OR, 8.0, CI, 8.0-8.1, P < .01; OR, 19.1, CI, 18.4-19.7, P < .01). Patients with other known cancers, bulky lymph node involvement, or small masses ranging from 2 to 4 cm in size were also more likely to be biopsied (P < .01).
“Nonacademic hospitals were more likely to biopsy,” he added. “It could be that these hospitals are using observation and thermal ablative therapies more frequently.” Conversely, wealthier patients, patients treated at academic hospitals, and patients treated in the Northeast were significantly less likely to be biopsied. (P < .01).
On the basis of the data analyzed in this study, Dr. Maurice and his colleagues concluded that there is a trend in use of renal mass biopsy in nonacademic centers in recent years, particularly among patients with small renal masses and in those who eventually undergo observation or focal ablative therapies. Lesser indications predicting the usage of renal mass biopsy include the existence of other primary cancers and bulky lymph nodes.
Dr. Maurice reported no relevant financial relationships.