Serum level of vascular endothelial growth factor (VEGF) as an independent prognostic factor in metastatic renal cell carcinoma (MRCC)

Abstract

5044 Background: The French Immunotherapy Group previously showed that circulating interleukin-6 (IL-6) and VEGF correlate with survival in MRCC patients (pts) (Négrier JCO 2004). We aimed to confirm the prognostic value of IL-6 and VEGF, and to test that of macrophage colony-stimulating factor (M-CSF) and macrophage inflammatory protein 3-alpha (MIP-3a) for survival in MRCC pts of good and intermediate prognoses. Patients and Methods: Pre-treatment samples were obtained from 302 MRCC pts enrolled in 2 parallel multicenter randomized cytokine trials. Baseline serum levels of IL-6, M-CSF, VEGF, and MIP3a were determined by immunoassays; their prognostic value for progression-free survival (PFS) and overall survival (OS) was tested. Characteristics of pts with a 0.15 significance level in univariate analysis (ECOG PS, prior therapy, metastatic sites and biological parameters) were entered in a multivariate Cox model. A backward stepwise procedure discriminated non-influential variables at 0.05 level. Results: Median IL6, VEGF, M-CSF and MIP3a levels were respectively 7.3 (range 0–392 pg/mL), 0.5 (0–2.3 ng/mL), 406 (0–4,785 pg/mL) and 0 (0–1,705 ng/mL). IL6 or M-CSF and VEGF (p<0.0001), or IL6 and M-CSF (p=0.0005) were significantly correlated. Death occurred in 192/302 pts, with 20.9 month median OS. OS was highly correlated with IL6, VEGF and M-CSF (p <0.001) but not with MIP3a (p=0.06) in univariate analysis. Only VEGF remained independently prognostic for OS in multivariate analysis (39% increased probability of death if VEGF level doubled) after adjustment on PS, time from diagnosis to metastasis, number of metastatic sites, pleural metastasis, abnormal sedimentation rate, haemoglobin and LDH levels. Similar results were found for PFS, with a hazard ratio of 1.19 for a 2-fold VEGF increase. Conclusions: The independent prognostic value of serum IL6 level is not confirmed in our cohort that excluded pts with poor outcome, but serum VEGF level appears as an independent prognostic factor, thus supporting the therapeutic interest for these pts of newly available drugs targeting VEGF receptors. No significant financial relationships to disclose.