Objective To explore the predictive value of neutrophil-to-lymphocyte ratio (NLR) on the therapeutic effects of immunotherapy in advanced cancer patients who can not detect PD-L1 expression levels, tumor mutation burden (TMB), and microsatellite instability-high (MSI-H).

Methods The data of 48 advanced cancer patients treated with PD-1 antibodies but cannot detect PD-L1, TMB, MSI-H in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from January 2020 to December 2021 were collected. Logistic regression was used to analyze the correlation between age, gender, primary tumor site, type of anti-PD-1 therapy, NLR and early efficacy. The optimal cut-off value of NLR predicting the disease control status was obtained by ROC curve. Patients were divided into NLR high-level group (n＝28) and NLR low-level group (n＝20) based on cut-off value of NLR. The early treatment efficacy between the two groups were compared.

Results Multivariate logistic regression analysis showed a significant correlation between baseline NLR and early treatment efficacy (P＝0.009). The optimal cut-off value of NLR for DCR was 3.54. Objective response rate (ORR) was 20.0% and 7.1% (P＝0.003) and disease control rate (DCR) was 85.0% and 35.7% (P＝0.001) in patients of the low NLR group and high NLR group, respectively.

Conclusions Baseline NLR has potential predictive value for early efficacy in advanced cancer patients treated with PD-1 monoclonal antibody therapy.