Individualized Surveillance Duration Best for Resected RCC Follow-Up

Appropriate follow-up of patients with resected non-metastatic renal cell carcinoma (RCC) should be based on a combination of risk factors for disease recurrence and risk for non-RCC death, according to an analysis published in the Journal of Clinical Oncology.

In the analysis by Igor Frank, MD, of the Mayo Clinic in Rochester, Minnesota, and colleagues, patients were stratified by pathologic stage, relapse location, age, and Charlson Comorbidity Index in order to identify points when risk for non-RCC death exceeded that of risk for disease recurrence.

“This approach eliminates the oversimplified stopping points that are recommended currently and allows a better prediction of a patient’s natural course of disease with RCC as it interacts with their overall health status,” wrote Frank and colleagues.

The researchers were referring to recommendations for surveillance issued by the National Comprehensive Cancer Network (NCCN) and the American Urological Association (AUA). The longest surveillance duration in either set of recommendations is 5 years; however, another recent study found that about one-third of all RCC recurrences would be missed by following the NCCN and AUA guidelines.

In order to attempt to create a more individualized surveillance strategy, Frank and colleagues studied 2,511 patients who underwent surgery for non-metastatic RCC during the 18-year period from 1990 to 2008. The median age of patients was 64 years. The majority of patients underwent follow-up that included physical examinations, laboratory testing, and abdominal and chest imaging quarterly for the first 2 years, semiannually for the next 3 years, and then annually. Parametric models for time-to-failure with Weibull distributions were used to estimate risks of disease recurrence and non-RCC death.

At a median follow-up of 9 years, 676 patients had developed disease recurrence after a median of 1.6 years post surgery. Death from RCC occurred in 435 patients after a median of 1.1 years from recurrence; 615 patients died from non-RCC causes after a median of 6.1 years post surgery.

The researchers found that among patients with pT1Nx-0 disease and a Charlson Comorbidity Index of 1 or less, the risk for non-RCC death was greater than that of abdominal recurrence at 6 months in patients aged 80 or older, which suggests that “routine surveillance beyond this point may be avoided,” according to the researchers.

However, in patients aged 50 to 59 years, the risk for non-RCC death did not begin to exceed that of recurrence until 7 years; for patients 60 to 69 years, 2.5 years; and for patients 70 to 79 years, 1.5 years. In patients aged younger than 50, it took longer than 20 years for the risk of non-RCC death to exceed the risk for abdominal recurrence, suggesting “a potential role for extended surveillance.”

By contrast, patients with pT1Nx-0 disease who had a Charlson Comorbidity Index of 2 or greater, the risk for non-RCC death exceeded that of abdominal recurrence by 30 days after surgery in patients of all ages.

The researchers concluded, “The documented limitations of the NCCN and AUA RCC surveillance guidelines, together with the transition of our health care system into a value-based system, has made the development of more effective follow-up strategies critically important. By using a novel technique that models competing risks factors, we show here how a more individualized RCC surveillance approach can be derived by estimating the time point at which a patient’s risk of non-RCC death exceeds the risk of recurrence.”