Radiofrequency ablation (RFA) may be an effective treatment option for select patients with small renal cancer masses, such as those who are elderly, have comorbidities, or have other active malignancies, according to a study presented at the 2010 Genitourinary (GU) Cancers Symposium in San Francisco.1 However, RFA needs to be applied very carefully; and for those patients whose tumors do not involute, it's advisable to perform follow-up biopsies, according to researchers at The University of Texas M. D. Anderson Cancer Center.

"You can't rely on CT or MRI to claim success based on lack of enhancement," said senior author Surena Matin, MD, Associate Professor of Urology at M. D. Anderson. The Symposium was cosponsored by ASCO, the American Society for Therapeutic Radiology and Oncology, and the Society of Urologic Oncology.

Survival Rates

In the single-institution study at M. D. Anderson, the cases of 124 patients who did not qualify or were unable to undergo surgery and who received RFA were retrospectively reviewed. The median age of patients was 70, and the median tumor size was 2.8 cm. The 1- and 3-year local recurrence-free survival rates were 99% and 94.6%, and the 1-, 3-, and 5-year overall survival rates were 92.4%, 84.5%, and 70.8%, respectively. Two patients had incomplete ablation and their tumors were reablated. In 29 patients, however, the tumors failed to involute, and biopsies were performed at a median time of 23 months postablation. Three of these patients had residual disease, although they showed no tumor enhancement on imaging, and they were retreated with either RFA or partial nephrectomy. Complications such as gross hematuria, acute hypertension, and pneumothorax affected 21 patients. Those with larger tumors were more likely to suffer complications, according to lead author Jose Karam, MD, a Urologic Oncology Fellow at M. D. Anderson.

"Radiofrequency ablation is a feasible and safe alternative to surgery that we can offer those who cannot undergo or tolerate surgery-but is not something we would offer to young, healthy patients," Dr. Karam said.

Need for Follow-up Biopsies

While other researchers have found that RFA can result in up to a 30% to 40% rate of residual disease, the M. D. Anderson data indicated a far higher success rate, noted Dr. Matin. These data, however, support the need for follow-up biopsies in patients whose tumors do not involute-and the importance of careful patient selection, he added. Biopsies should be considered in patients whose tumors do not involute 6 months or later after treatment, he said.

"For those with underlying medical conditions or who are too sick for surgery, radiofrequency ablation may be the preferred approach," commented Nicholas Vogelzang, MD, Chair and Medical Director of the Developmental Therapeutics Committee of US Oncology, and Vice Chair of the genitourinary committee of the Southwest Oncology Group. "It's an evolving technology, but people need to be aware that you can't always expect complete eradication of the tumor, and these patients need to be watched quite carefully," he said.

Reference

1. Karam JA, Ahar K, Jonasch E, et al: Radiofrequency ablation (RFA) of renal tumors: Clinical, radiographic and pathologic results from a tertiary care center. 2010 Genitourinary Cancers Symposium. Abstract 316. Presented March 7, 2010.