Retrospective Analysis of Neutrophil-to-Lymphocyte Ratio in Patients with Melanoma Who Received Ipilimumab Monotherapy or Ipilimumab in Combination with Nivolumab in Japan

Studies have reported an association between elevated neutrophil-to-lymphocyte ratio (NLR) and poor prognosis in patients with melanoma treated with ipilimumab. However, it remains unclear whether NLR is useful in Japanese patients with melanoma, and if so, what is the optimal cut-off value. We retrospectively examined 38 patients who received ipilimumab from August 2015 to November 2021 at Nagoya University Hospital. We divided patients into two groups: 1–2 versus 3–4 cycles of ipilimumab. In univariate analysis, baseline neutrophil count and NLR were significantly higher in patients who discontinued ipilimumab within 2 cycles. With receiver operating characteristic analysis, the optimal NLR cut-off value was found to be 3.4 (area under the curve, 0.75; 95% confidence interval, 0.58–0.92). In multivariate logistic regression analysis, baseline NLR >3.4 was an independent risk factor for ipilimumab discontinuation (odds ratio, 15.6; 95% confidence interval, 3.0–82) that was significantly associated with shorter progression-free survival (PFS) (p=0.003, log-rank test). In conclusion, NLR >3.4 is useful for selecting Japanese patients with melanoma who might have better PFS with ipilimumab-containing treatment. Because the optimal NLR cut-off value in this study was lower than values in American and European studies, it possibly differs by race. Hence, it should be extrapolated to Japanese patients with caution.