Background:There are no validated markers that predict response in metastatic renal cell cancer (RCC) patients treated with sunitinib. We aim to study the impact of single-nucleotide polymorphisms (SNPs) that have recently been proposed as predictors of outcome to anti-VEGF-targeted therapy in metastatic RCC in an independent cohort of patients.Methods:We genotyped 16 key SNPs in 10 genes involved in sunitinib pharmacokinetics, pharmacodynamics and VEGF-independent angiogenesis in patients with metastatic clear-cell RCC treated with sunitinib as the first-line targeted therapy. Association between SNPs, progression-free survival (PFS) and overall survival (OS) were studied by multivariate Cox regression using relevant clinical factors associated with PFS and OS as covariates.Results:In a series of 88 patients, both PFS and OS were associated significantly with SNP rs1128503 in ABCB1 (P=0.027 and P=0.025), rs4073054 in NR1/3 (P=0.025 and P=0.035) and rs307821 in VEGFR3 (P=0.032 and P=0.011). Progression-free survival alone was associated with rs2981582 in FGFR2 (P=0.031) and rs2276707 in NR1/2 (P=0.047), whereas OS alone was associated with rs2307424 in NR1/3 (P=0.048) and rs307826 in VEGFR3 (P=0.013).Conclusion:Our results confirm former communications regarding the association between SNPs in ABCB1, NR1/2, NR1/3 and VEGFR3 and sunitinib outcome in clear-cell RCC. Prospective validation of these SNPs is now required.

Neoadjuvant TMT appears to have limited effects on renal tumor thrombi. This retrospective study failed to demonstrate a significant impact of neoadjuvant TMT on surgical management of clear cell renal cell carcinoma with inferior vena cava tumor thrombi.

p75NTR, a member of TNF receptor family, is the low affinity receptor common to several mature neurotrophins and the high affinity receptor for pro-neurotrophins. Brain-Derived Neurotrophic Factor (BDNF), a member of neurotrophin family has been described to play an important role in development and progression of several cancers, through its binding to a high affinity tyrosine kinase receptor B (TrkB) and/or p75NTR. However, the functions of these two receptors in renal cell carcinoma (RCC) have never been investigated. An overexpression of p75NTR, pro-BDNF, and to a lesser extent for TrkB and sortilin, was detected by immunohistochemistry in a cohort of 83 clear cell RCC tumors. p75NTR, mainly expressed in tumor tissues, was significantly associated with higher Fuhrman grade in multivariate analysis. In two derived-RCC lines, 786-O and ACHN cells, we demonstrated that pro-BDNF induced cell survival and migration, through p75NTR as provided by p75NTR RNA silencing or blocking anti-p75NTR antibody. This mechanism is independent of TrkB activation as demonstrated by k252a, a tyrosine kinase inhibitor for Trk neurotrophin receptors. Taken together, these data highlight for the first time an important role for p75NTR in renal cancer and indicate a putative novel target therapy in RCC.

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(2014) Efflux pump ABCB1 single nucleotide polymorphisms and dose reductions in patients with metastatic renal cell carcinoma treated with sunitinib,