Clinical factors associated with outcome in patients with metastatic clear-cell renal cell carcinoma treated with vascular endothelial growth factor-targeted therapy.

BACKGROUND

Therapy targeted against the vascular endothelial growth factor (VEGF) pathway is a standard of care for patients with metastatic renal cell carcinoma (RCC). The identification of patients who are more likely to benefit from these agents is warranted.

METHODS

In total, 120 patients with metastatic clear-cell RCC received bevacizumab, sorafenib, sunitinib, or axitinib on 1 of 9 prospective clinical trials at the Cleveland Clinic. Clinical features associated with outcome were identified by univariate analysis; then, a stepwise modeling approach based on Cox proportional hazards regression was used to identify independent prognostic factors and to form a model for progression-free survival (PFS). A bootstrap algorithm was used to provide internal validation.

RESULTS

The overall median PFS was 13.8 months, and the objective response according to the Response Criteria in Solid Tumors was 34%. Multivariate analysis identified time from diagnosis to current treatment <2 years; baseline platelet and neutrophil counts >300 K/microL and >4.5 K/microL, respectively; baseline corrected serum calcium <8.5 mg/dL or >10 mg/dL; and initial Eastern Cooperative Oncology Group performance status >0 as independent, adverse prognostic factors (PF) for PFS. Three prognostic subgroups were formed based on the number of adverse prognostic factors present. The median PFS in patients with 0 or 1 adverse prognostic factor was 20.1 months compared with 13 months in patients with 2 adverse prognostic factors and 3.9 months in patients with >2 adverse prognostic factors.

CONCLUSIONS

Five independent prognostic factors for predicting PFS were identified and were used to categorize patients with metastatic RCC who received VEGF-targeted therapies into 3 risk groups. These prognostic factors can be incorporated into patient care and clinical trials that use such novel, VEGF-targeted agents.