Active surveillance may be viable option for small renal masses

Active surveillance may be a viable short-term treatment option in select patients with small renal masses, say researchers from Fox Chase Cancer Center, Philadelphia.

With an increase in abdominal imaging over the past decade, there has been an increase in the detection of incidental kidney cancer, which has led to concerns that physicians may be overtreating indolent disease. Thus, clinicians have started to investigate the effectiveness of active surveillance for select patients with small renal masses.

"Kidney cancer is most often a surgically treated disease, so studies such as this one, which help to confirm that active surveillance with curative intent can be an effective strategy for certain patients, are crucial," said co-author Marc Smaldone, MD. "The ability to offer a management strategy that avoids the risks of potentially unnecessary surgery is an attractive concept in contemporary cancer treatment."

To further investigate the risks of cancer progression in patients undergoing active surveillance, Dr. Smaldone, working with Robert G. Uzzo, MD, and colleagues, combined all the available individual data published by institutions examining the observation of small renal masses. The team identified and pooled a total of 18 institutional series. The researchers then examined the pooled experience for trends in radiographic growth rates, tumor size at presentation, and progression to treatment or metastasis.

They found that, of the observed 936 small renal masses in 880 patients, only a very small proportion-2.1% (18 patients)-progressed to metastasis. Pooled analysis of progressors and non-progressors revealed significant trends, including increased age, increased tumor size at presentation, and increased growth rates in the progression group. However, the researchers learned that growth kinetics alone cannot predict a tumor’s natural growth history. Therefore, active surveillance should not be considered an equivalent alternative to definitive surgical therapy, but it can be used as an initial short-term option for select patients who are poor surgical candidates.