Background: While programmed cell death protein 1 (PD-1) inhibitors benefit breast cancer patients, simple predictors of their efficacy are lacking. Objectives: This study aimed to evaluate inflammatory markers as prognostic indicators for advanced breast cancer (ABC) patients receiving immunotherapy. Design: This is a single-center retrospective study of ABC patients treated with PD-1 inhibitors between January 2016 and June 2022. Methods: Clinicopathological parameters, tumor-infiltrating lymphocytes (TILs) levels, and inflammatory markers—C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), and lymphocyte-to-monocyte ratio (LMR)—were collected from 116 ABC patients at baseline and after three cycles of immunotherapy (CRP3, NLR3, LMR3). Optimal cut-offs were defined using R software and associations with progression-free survival (PFS), overall survival (OS), and objective response rate were assessed. Results: Low baseline CRP, low NLR, and high LMR were significantly associated with improved PFS and OS (all p < 0.05) by Kaplan–Meier analysis. On multivariate analysis, low NLR3 and a reduced CRP3/CRP ratio independently predicted prolonged PFS ( p < 0.05). Patients with low CRP, reduced CRP3/CRP ratio, low NLR, and low NLR3 achieved better OS ( p < 0.05). Combining inflammatory markers with TIL status improved prognostic classification: TIL-deficient patients with high NLR3 (median PFS (mPFS): 2.89 months) or high CRP3/CRP ratio (mPFS: 1.90 months) had the poorest survival ( p < 0.05). Conclusion: CRP and NLR are promising biomarkers for predicting outcomes of PD-1 inhibitor therapy in ABC, with potential utility in individualizing immunotherapy strategies.
Wang et al. (Fri,) studied this question.