The absolute lymphocyte count can predict the overall survival of patients with non-small cell lung cancer on nivolumab: a clinical study

IntroductionThe neutrophil-to-lymphocyte (ANC/ALC) ratio is associated with worse prognosis in patients with NSCLC on immunotherapies, but the role of ALC remains unclear. The previous radiation therapy causes lymphopenia, and given approaches of combining radiation with immunotherapies, it is critical to better understand the impact of peripheral lymphocytes.Patients and methodsWe evaluated retrospectively 22 patients with advanced NSCLC treated with nivolumab at Boston Medical Center from January 2014 to September 2016 and correlated the peripheral blood counts with the overall survival (OS) and overall time on treatment. We assessed the effect of the previous radiation on peripheral blood counts and clinical outcomes.ResultsBaseline ALC and ANC/ALC ratios are positively and negatively correlated, respectively, with the OS on nivolumab. The ALC and ALC/WBC ratios at 6weeks on treatment are positively associated with the OS. Kaplan-Meier analysis at baseline and at 6weeks showed significantly increased OS in the group of patients with the highest ALC. The previous radiation therapy was positively correlated with the ANC and negatively correlated with the ALC/WBC ratio at 8weeks after the initiation of nivolumab.ConclusionOur finding that ALC at baseline and at 6weeks on treatment is positively correlated with the OS provides an easily obtained predictive marker. Our result that the previous radiation is associated with higher ANC and lower ALC during treatment supports that the combination of radiation therapy with immunotherapy should be carefully applied and potentially peripheral blood counts can be utilized to stratify patients for this approach.