In a randomized phase III trial, sunitinib was associated with significantly superior progression-free survival when compared with interferon alfa as first-line therapy in patients with metastatic renal cell carcinoma. This article investigates whether baseline quality of life and demographic and clinical variables were predictive for progression-free survival.
In a randomized phase III trial, sunitinib was associated with significantly superior progression-free survival (PFS) when compared with interferon alfa (IFN-α) as first-line therapy in patients with metastatic renal cell carcinoma. We investigated whether baseline quality-of-life (QOL) and demographic and clinical variables were predictive for PFS.
Patients were randomly assigned to receive sunitinib or IFN-α at a ratio of one to one. QOL was measured using the Functional Assessment of Cancer Therapy–General scale (FACT-G), the FACT–Kidney Symptom Index–Disease-Related Symptoms subscale (FKSI-DRS), and the EuroQol (EQ) Group's visual analog scale (EQ-VAS; Rotterdam, the Netherlands). In all scales, higher scores indicate better QOL or fewer symptoms. Controlling for other baseline demographic and clinical variables, Cox proportional hazards models—one for each QOL variable—were used to test if difference in baseline QOL scores predicted PFS.
The superior treatment effect on PFS of sunitinib versus IFN-α remained robust (hazard ratio [HR], 0.34, 0.33, and 0.33 for each model, respectively; P < .0001 for each model). Higher baseline FACT-G, FKSI-DRS, and EQ-VAS scores were associated with longer PFS (HR, 0.93, 0.89, and 0.91, respectively; P ≤ .001, P ≤ .001, and P = .008, respectively). Presence of liver metastases (HR, 1.59 to 1.71; P = .0009 to .0044) and number of Memorial Sloan-Kettering Cancer Center (MSKCC; New York, NY) risk factors (HR, 1.52 to 1.60; P < .0001 for each) were significant negative predictors of PFS, independent of other variables.
Sunitinib conferred significantly superior PFS compared with IFN-α, irrespective of baseline QOL or clinical characteristics. Higher baseline QOL correlated with longer PFS, whereas the presence of liver metastases and more MSKCC risk factors at baseline correlated with shorter PFS. This remains an area for future study.