Blood tests predict the therapeutic prognosis of anti-PD-1 in advanced biliary tract cancer.

Predictive prognostic markers for immunotherapy are crucial and desperately required for clinical precise medicine. This retrospective study aimed to assess the efficacy of anti-PD-1 (programmed cell death protein 1) treatment and find the therapeutic prognostic biomarkers in advanced biliary tract cancer (BTC). A total of 60 patients of advanced BTC who received at least one dose of anti-PD-1 therapy between June 2016 and October 2019 were recruited and followed up till April 2020. Systemic immune-inflammation index (SII) and neutrophils-to-lymphocytes ration (NLR) were obtained from the routine circulating hematologic analysis before treatment. Serum 45-Plex Panel cytokines were detected using multiplexed bead immunoassays. Logistic regression nomogram was used to construct the algorithm model for prognosis prediction. Of the 60 patients, the overall benefit rate (OBR) was 38.3%, the median progression free survival (PFS), and overall survival (OS) were 4.0 mo (95% confidence interval [CI]: 2.28-5.72) and 13.0 mo (95% CI: 8.05-17.95), respectively. High levels of SII (≥720), NLR (≥4.3) and cytokine IFN-inducible protein-10 (IP-10; ≥45 pg/ml) indicated worse OS. Those with high SII (≥720) and high IP-10 (≥45 pg/ml) also had shorter PFS. The nomogram algorithm combining above three independent factors (SII, IP-10, and macrophage inflammatory protein-1β) had better efficacy in predicting OBR. Our study offers a simple, affordable, and noninvasive method to help physicians predict therapeutic response in BTC patients receiving anti-PD-1 antibody treatment.