MP25-17 NEUTROPHIL- AND PLATELET-TO-LYMPHOCYTE RATIOS AS PROGNOSTIC FACTORS OF DISEASE-FREE SURVIVAL IN HIGH-RISK RENAL CELL CARCINOMA

Abstract

INTRODUCTION AND OBJECTIVES: Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are reported to predict clinical outcomes in patients with metastatic renal cell carcinoma (mRCC). Adjuvant sunitinib (SU) significantly improved disease-free survival (DFS) vs placebo (PBO) in patients with locoregional RCC at high risk of recurrence post nephrectomy (S-TRAC trial). This study aimed to evaluate NLR and PLR as potential prognostic factors in high-risk loco-regional non-metastatic RCC. METHODS: Post-hoc exploratory analysis of the high-risk STRAC trial patients. Kaplan-Meier estimates and Cox proportional analyses were performed on baseline and change from baseline at Week 4 NLR and PLR to assess their association with DFS. P-values were two-sided and based on an unstratified log-rank test. RESULTS: 609/615 patients had NLR and PLR baseline values; 574 patients had paired values at both baseline and at Week 4. Cut-off values were defined as NLR <3 vs ≥3 and PLR <140 vs ≥140, based on ROC curves. The significantly shorter DFS of baseline NLR <3 vs NLR ≥3 in PBO patients (HR 0.63, P=0.04), was eliminated by SU treatment (HR 0.91, P=0.67). SU Patients with baseline NLR <3 had significantly longer DFS vs PBO (median DFS 7.1 vs 4.7 years; HR 0.71, P=0.02); however, DFS was similar regardless of treatment for baseline NLR ≥3 (HR 1.03, P=0.91). No statistically significant differences in DFS were observed for baseline PLR (<140 vs ≥140) in the overall (HR 0.91, P=0.45), SU (HR=0.83, P=0.33) or PBO (HR=0.97, P=0.87) population; however, there was a trend toward longer DFS in SU patients with baseline PLR <140. Overall, a ≥25% decrease in NLR or PLR at Week 4 was associated with longer DFS vs no change (NLR, HR 0.71 [P=0.01]; PLR, HR 0.76 [P=0.05]). A greater proportion of patients had a ≥25% decrease in NLR or PLR at Week 4 when treated with SU (NLR, n=200 [71.2%]; PLR, n=175 [62.3%]) vs PBO (NLR, n=51 [17.4%]; PLR, n=43 [14.7%]). Patients with ≥25% decrease in NLR or PLR at Week 4 continued on to receive a higher median cumulative dose of SU (NLR 10137.5 mg; PLR 9856.3 mg) vs those with no change (NLR 8168.8 mg; PLR 9418.8 mg) or ≥25% increase (NLR 6712.5 mg; PLR 6425.0 mg). CONCLUSIONS: Low baseline NLR, and a ≥25% decrease in NLR or PLR after 4 weeks, could both be early predictors of those highrisk patients most likely to benefit from adjuvant SU. NLR and PLR changes at Week 4 appeared to separate those most likely to tolerate and respond to adjuvant SU, eliminating potential toxicity risk in those least likely to benefit.