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In metastatic renal cell carcinoma (RCC), prognostic factors are important for patient counseling, clinical studies, and selection of different treatments, says Daniel Heng, MD. Heng’s practice uses International mRCC Database Consortium (IMDC) criteria to evaluate prognosis, which involves testing for 6 adverse clinical factors: Karnofsky performance status less than 80%; diagnosis-to-treatment interval less than 1 year; and abnormal levels of hemoglobin, platelets, neutrophils, or calcium.
Patients without any of risk factors have a more favorable risk profile and a medium overall survival of 44 months. Those with 1 or 2 risk factors are at intermediate risk with a medial overall survival of 27 months, and poor risk patients (those with 3 or more risk factors) have a median survival of 8.8 months. Risk stratification then dictates treatment. For example, poor risk patients can receive temsirolimus because its use has been studied in poor risk populations. Brian Rini, MD, adds that he tends to be more aggressive in dose titration in patients with poorer prognoses because this population does not have the comfort of waiting for their physicians to gradually titrate doses.
When making treatment decisions, Janice Dutcher, MD, states she that she considers whether patients are candidates for interleukin-2 (IL-2). When evaluating candidacy, Dutcher notes that she looks at the patient’s performance status; those with Karnofsky scores of 90% to 100% tend to have the best outcomes with IL-2 therapy. IL-2 has been shown to cause durable complete responses, which Dutcher notes is her primary objective. Her secondary goals are to maintain patients on a plateau for as long as possible, which is where she sees the role of tyrosine kinase inhibitors and mTOR inhibitors.
When compared with the interferon era, the IL-2 era has been associated with a doubling of overall survival for each of the low, intermediate, and high risk categories, which Heng points out is a testament to the efficacy of targeted therapies. Rini, however, notes that although research in the past 10 years has focused on biomarkers and genetic variations that might predict response, treatment decisions still predominantly depend on basic clinical factors.