Study identifies promising treatment for kidney cancers

A study of patients with kidney cancer has shown that radiofrequency ablation, a minimally invasive, kidney-sparing procedure, can be a successful treatment option for patients whose cancer has not spread beyond the kidney, report researchers at Wake Forest Baptist Medical Center.

Results from the three year study, which evaluated 22 patients who received the treatment, are published in the July issue of the American Journal of Roentgenology. The treatment uses computed tomography to guide the placement of a special needle-shaped electrode into the tumor. A radiofrequency current is then passed through the electrode to heat the tumor tissue and ablate – or eliminate – it.

Complete tumor ablation was achieved after a single treatment in 83 percent of the patients; an additional eight percent had complete tumor ablation after two or more treatments. None of the patients had long-term or serious complications. “These results are significant and encouraging because the incidence of kidney cancer in the United States has increased by 126 percent over the past 50 years,” said Ronald J. Zagoria, professor of radiologic sciences at Wake Forest Baptist and principal investigator of the study.

For the past 50 years, the standard of care for kidney cancer has been radical nephrectomy – removal of the kidney. More recently, partial nephrectomy has been shown to have equivalent results for curing small low-stage renal cancers, indicating that kidney-sparing procedures can be curative. However, nephrectomy is not ideal for many patients, such as those who cannot tolerate surgery because of other health-related conditions.

Advances in imaging techniques have resulted in detecting the tumors when they are much smaller, often in patients who show no symptoms. The success of radiofrequency ablation in treating kidney cancer is largely dependent on tumor size.

In this study, tumors smaller than 3 cm in diameter were completely ablated with a single treatment. Residual tumor was found only in patients with tumors greater than 3.1 cm, suggesting that larger tumors are more difficult to eradicate completely with radiofrequency ablation.

“Radiofrequency ablation offers us another potentially curative option for appropriate patients,” said Zagoria. While additional studies are needed to determine its long-term success, it could prove to be a useful treatment for patients who are not ideal surgical candidates. In addition, the length of hospital stay, cost and risk of complications for radiofrequency ablation are projected to be less than for nephrectomy.