A novel approach to oncologic surveillance after surgical resection for renal cell carcinoma (RCC) that incorporates patient age, Charlson comorbidity index, pathologic tumor stage, and relapse location–specific data, may provide better recommendations for surveillance duration than current guidelines, researchers reported.
“By providing more individualized recommendations and by eliminating oversimplified time thresholds for surveillance, this strategy, we believe, represents an improvement over current guidelines,” wrote Dr. Suzanne Stewart-Merrill of the department of urology, Mayo Clinic, Rochester, Minn., and colleagues (J Clin Oncol. 2015 Sep 7. doi: 10.1200/JCO.2015.61.8009).
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Guidelines suggest surveillance durations based on cumulative incidence of recurrences, but do not account for individual patient risk factors. Adherence to the guidelines could miss up to one-third of all recurrences, the authors noted. The longest surveillance duration advocated by the National Comprehensive Cancer Network or the American Urological Association is 5 years.
Researchers used Weibull models for risk of recurrence, stratified by stage and relapse location, combined with risk estimates for non-RCC death, to estimate the optimum surveillance duration. For example, for patients aged 50-59 years with pT1Nx-0 disease and a Charlson comorbidity index of less than or equal to 1, risk of non-RCC death exceeded the risk of abdominal recurrence at 7 years, marking the recommended surveillance duration for that subgroup. The recommended surveillance duration for patients with similar characteristics aged 60-69 years is 2.5 years, and for patients aged 70-79 years it is 1.5 years.
When taking into account individual risk factors, the method produced a wide range of surveillance durations. For patients under 50 years old with pT1Nx-0 disease and a Charlson comorbidity index less than or equal to 1, the risk of non-RCC death did not exceed the risk of abdominal recurrence for more than 20 years. By contrast, patients with pT1Nx-0 disease and Charlson comorbidity index greater than or equal to 2, had a higher risk of non-RCC death than risk of abdominal recurrence at 30 days after surgery.
The retrospective study of 2,511 patients who underwent surgical resection for M0 sporadic RCC between 1990 and 2008 had a median follow up of 9.0 years (interquartile range 6.4-12.7 years).
The researchers noted that recurrences beyond 5 years are fairly common, with up to 15% of patients, by one study’s estimate, experiencing recurrence during the decade following surgery. Cumulative incidence of recurrence does not capture how a patient’s risk of recurrence changes with time or how comorbid conditions influence risk.
The proposed surveillance method results in shorter surveillance durations for some patients and longer surveillance durations than currently recommended for others. This diversity in stopping points “better reflects the range of disease courses appreciated in patients with RCC on the basis of the interplay that occurs between the risk of recurrence and other competing health factors,” Dr. Stewart-Merrill and associates explained.
Dr. Stewart-Merrill reported having no disclosures.