Surveillance, ablation important for management of small renal masses

MIAMI — Despite varying guidelines, surveillance and ablation may have an increasing role in the management of small renal masses, according to a presenter at International Kidney Cancer Symposium.

R. Houston Thompson, MD, professor of urology at Mayo Clinic in Rochester, Minn., compared ASCO, European Association of Urology, American Urological Association and Canadian Urological Association guidelines for the management of small renal masses.

He focused on the quality of data used to make the guidelines, the difference between guidelines and the potential for a unified message.

Using a manual search for the management of small renal masses, the Canadian Urological Association in 2015 recommended the following:

Partial nephrectomy is recommended, including open, laparoscopic or robot;
Lap radical nephrectomy should be reserved for tumors not amenable to partial nephrectomy. Open partial nephrectomy is preferred to laparoscopic radical nephrectomy;
Ablation is an option. A biopsy should be obtained before or during ablation. A laparoscopic approach is unnecessary. There is reduced success for endophytic central tumors; and
Active surveillance is a primary consideration for elderly and infirm patients.

“The Canadian Urological Association stated that there are reduced success rates for endophytic central tumors, and this can be performed without general anesthesia,” Thompson said during his presentation. “I would state that, for patients with endophytic central tumors, general anesthesia allows you to control their bleeding and better treat these central tumors.”

Using the PRISMA literature review for management options, the European Association of Urology in 2015 issued the following guidelines:
Partial nephrectomy is recommended. Surgery is the only curative treatment with high-quality evidence;
Laparoscopic radical nephrectomy is recommended for renal masses that are not treatable by partial nephrectomy;
No recommendation can be made on ablation due to data quality. However, ablation can be offered to elderly/comorbid patients unfit for surgery, as well as those with renal cell carcinoma syndromes, bilateral tumors and solitary kidney with high risk for dialysis. It is not recommended for larger tumors, or those near hilum or ureter; and
Active surveillance can be offered to elderly/comorbid patients.

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Using the BRIDGE-Wiz literature review for the management of renal small masses, ASCO issued a guideline that year that recommended the following:

Active surveillance should be the initial option for patients with limited life expectancy, defined as less than 5 years, or less than 10 years if the mass is less than 1 cm. However, oncologists should consider treatment if there is more than 5 mm in tumor growth per year or the tumor is more than 4 cm in size;
Partial nephrectomy is standard for those who need treatment;
Ablation is an option when complete ablation can be achieved. A biopsy should be obtained before or during ablation. The historical notion that ablation is limited to vulnerable patients is discouraged; and
Radical nephrectomy should be reserved for significant tumor complexity that is not amenable to partial nephrectomy, even at centers with expertise.

ASCO also recommended against biopsies for patients with masses originating in the collecting system. However, Thompson disagreed.

“We have been performing biopsies for a long time at Mayo Clinic and, in fact, for patients with locally advanced urothelial carcinoma of the kidney, I get better results from a percutaneous biopsy,” he said.

Using the AHRQ literature review for management options, the American Urological Association this year issued the following guidelines:

Physicians should prioritize partial nephrectomy when intervention is indicated. Most cT1b/T2 tumors can be considered for partial nephrectomy;
Radical nephrectomy is preferred if there is high tumor complexity, no chronic kidney disease or proteinuria, normal contralateral kidney and the new eGFR after treatment is more than 45. This should be avoided, if possible, for cT1a tumors;
Ablation is an alternate approach if a tumor is less than 3 cm. A percutaneous technique is preferred, and physicians should counsel those with higher risk or local recurrence; and
Active surveillance is an acceptable option, especially for renal masses less than 2 cm. Physicians should consider this intervention if there is more than 5 mm of tumor growth per year or the tumor is greater than 3 cm in size.

“I think we can expand [the use of thermal ablation] to tumors larger than 3 cm. This statement applies to radiofrequency ablation,” Thompson added.

Because the large majority of cT1a renal masses have low metastatic potential, surveillance, ablation and surgery are options that need to be tailored to the individual patient, Thompson added.

“Going forward, surveillance and ablation will have increasing roles as their safe utility is further studied and supported,” he said. by Kristie L. Kahl

Reference:

Thompson RH. Guidelines on managing SRMs: Compare and contrast. Presented at: International Kidney Cancer Symposium; Nov. 3-4, 2017; Miami.

Disclosure: Thompson is a member of the ASCO guideline committee.