April 15, 2017
Active Surveillance for Renal Cell Cancer
MILAN, Italy—Criteria for withholding aggressive therapies early in the course of renal cell cancer were updated at the 2016 European Multidisciplinary Meeting on Urological Cancers (EMUC) by Phillip M Pierorazio MD, Assistant Professor of Urology and Oncology at Johns Hopkins University, Baltimore MD.
“In clinically localized small masses—four centimeters or smaller—the first-line option is non-surgical management—active surveillance—for many patients,” he said, and he went on to discuss the latest evidence on minimizing the risk of unnecessary treatment emerging from his group’s registry of patients with renal tumors.
While there has been much encouraging news about new treatments for advanced and resistant renal cancer there was need to reassure many patients that they do not need to treat early stages of the disease urgently, Pierorazio said. Most patients could take time to allow teams to gather the clinical data needed to make considered decisions based on risk/benefit assessment.
Many Tumors Not Dangerous
“What we try to impart is that most small renal masses are not dangerous. In fact upwards of 20 to 30 percent are benign. The majority of the cancers are low-grade indolent tumors or not dangerous cancers,” he said.
He recognized that some patients particularly wanted to avoid surgery and—for them—an active surveillance management strategy was viewed as a completely safe option—at least in the short term.
Pierorazio said there were penalties for proceeding with active therapy.
“No kidney surgery is without risk. The kidney is a very vascular organ. It gets a quarter of the body’s blood-flow per minute. So temporarily stopping blood-flow, removing tumors [and] reconstructing kidneys subjects patients to risks that they may not necessarily need.”
During surveillance, however, there were triggers for intervention, he said.
“We image every six months for two years then annually thereafter. Historically the biggest trigger for intervention has been a growth rate of greater than half a centimeter per year. But that’s probably not the right trigger.”
He highlighted, instead, the importance of overall tumor size, pointing out that a marked upswing of risk that a patient will have a serious cancer—from below one percent to the order of two to three percent—typically began at around a diameter of four centimeters. So he regarded monitoring tumor size as a key factor in decision-making.
When he was asked about outcomes following active surveillance as compared with more aggressive approaches he said that in his group’s registry study of patients with early renal cancer only two out of 500 patients died of kidney cancer, both of whom had up-front surgery.
“None of the patients in the active surveillance cohort has developed metastatic disease or died of kidney cancer. 30 per cent of them “progressed”—meaning their tumors grew, but only about 15 percent of them crossed over into intervention,” he said.
Best Candidates for Active Surveillance?
“We know that tumors of less than two centimeters are really indolent,” said Pierorazio. “We do not miss a window of opportunity for treatment or cure if we allow them to grow and keep an eye on them, and most of them will not grow or change.”
Although teams have traditionally regarded older patients who have comorbidities as candidates for active surveillance there was, in fact, another distinct group. “Any patient with a small tumor is certainly eligible for active surveillance,” he said.
“Active surveillance is a safe option for all patients with clinical T1A tumors—four centimeters or less. It really should be our first-line management for patients who are older with co-morbidities, but it can be considered first-line management for any patient with a tumor less than two centimeters.”