1789 PREDICTION OF TKI-THERAPY RESPONSE IN PATIENTS WITH METASTATIC RENAL CELL CARCINOMA BY SERUM PROTEOMICS

p44/42 mitogen-activated protein kinase (MAPK) and signal transducers and activation of transcription 3 (STAT3), vascular endothelial growth factor receptor (VEGFR)-1 and -2, and platelet-derived growth factor receptor (PDGFR)and , in primary RCC specimens were measured by immunohistochemical staining. RESULTS: Of several factors examined, tumor grade and the expression level of VEGFR-2 were shown to have significant impact on response to sunitinib in these 60 patients. Progression-free survival (PFS) was significantly associated with the expression levels of VEGFR-2 in addition to tumor grade, performance status, MSKCC risk classification system and c-reactive protein level on univariate analysis. Of these significant factors, only VEGFR-2 expression appeared to be independently related to PFS by multivariate analysis. In fact, the PFS in patients with strong expression of VEGFR-2 was significantly favorable compared with that in those with weak expression of VEGFR-2. CONCLUSIONS: It would be useful to consider expression levels of potential molecular markers, particularly VEGFR-2, as well as conventional parameters to select metastatic RCC patients likely to benefit from treatment with sunitinib.