Predictive factors for response to treatment in patients with advanced renal cell carcinoma

Introduction The analysis of predictive factors of response may aid in predicting which patients with advanced renal cell carcinoma (RCC) would be good candidates for systemic treatments. Materials and methods The expression of several biomarkers was retrospectively analyzed using immunohistochemistry (IHC), as well as 2 analytical variables in 135 patients with advanced RCC treated with cytokines (CK) and/or new targeted drugs (NTD). Results 67 patients were treated solely with NTD and 68 with CK (23 also received NTD). Univariate analysis: HIF1α did not correlate significantly with response to these drugs. Overexpression of CAIX was associated with more responses (%) to NTD (64.7 vs. 21.1; p = 0.004) and CK (22.6 vs. 0; p = 0.038). PTEN demonstrated predictive value of response to sunitinib (70.8 vs. 34.1; p = 0.005). p21 was associated with a lower response to sunitinib (35.9 vs. 65.4; p = 0.025). Thrombocytosis was not significantly associated with response to NTD, although it was with CK (0 vs. 20; p = 0.017). Neutrophilia correlated with a lower response to NTD (29.6 vs. 57.5; p = 0.045), although not with CK. Multivariate analysis: Overexpression of CAIX was an independent predictor of significantly higher response to NTD and CK; OR = 8.773 (p < 0.001). Conclusions Our findings highlight the usefulness of CAIX in selecting patients with advanced RCC as candidates for systemic treatment. PTEN and p21 may be important in predicting response to sunitinib. Thrombocytosis and neutrophilia correlate well with response to CK and NTD, respectively.