The association of pre-treatment neutrophil to lymphocyte ratio with response rate, progression free survival and overall survival of patients treated with sunitinib for metastatic renal cell carcinoma

Background: Sunitinib is a standard treatment for metastatic renal cell carcinoma (mRCC). The neutrophil to lymphocyte ratio (NLR), an index of systemic inflammation, is associated with outcome in several cancer types. Aims: To study the association of pre-treatment neutrophil to lymphocyte ratio with response rate, progression free survival (PFS) and overall survival (OS) of patients treated with sunitinib for mRCC. Methods: We retrospectively studied an unselected cohort of patients with mRCC, who were treated with sunitinib. Logistic regression model was used to analyse response rate. Cox regression models were fitted to identify risk factors associated with PFS and OS. We investigated how pre-treatment NLR is associated with these clinical outcomes after adjusting for confounding covariates. Regression tree for censored data method was used to find the best NLR cut-off value. Results: Between 2004 and 2011, 133 patients with mRCC were treated with sunitinib. One hundred and nine were included in the NLR analysis, from which were excluded patients without available data on pre-treatment NLR or with comorbidities/recent treatments known to be associated with a change of blood counts. Factors associated with PFS were low NLR ≤ 3 (HR = 0.285, p < 0.001), past nephrectomy (HR = 0.38, p = 0.035), sunitinib dose reduction/treatment interruption (HR = 0.6, p = 0.014) and the use of antiotensin system inhibitors (HR = 0.537, p = 0.008). Low NLR ≤ 3 was associated with OS (HR = 0.3, p = 0.043). Conclusions: In patients with mRCC treated with sunitinib, pre-treatment NLR may be associated with PFS and OS. This should be investigated prospectively, and if validated applied in clinical practice and clinical trials.