Predictive Role of Peripheral Blood Lymphocyte And Cytokine Phenotypes in Patients with Operable Breast Cancer And Neoadjuvant Therapy: A Preliminary Study

Background PD-L1 is an indicator for immunotherapy however, the detection is based on biopsy and affected by tumor heterogeneity and patients’ intolerance. This study aimed to explore convenient alternatives for PD-L1 tissue detection. Methods With 134 cases recruitment, the peripheral lymphocyte subtypes and cytokines was detected by flow cytometry and PD-L1 expression in tumor microenvironment (TME) was detected by immunohistochemistry and assessed by two qualified pathologists. Results The patients with positive PD-L1 expression had peripheral CD8 + /CD28 + T lymphocytes 20% higher than those with negative expression ( p = 0.008) with the area under the receiver operating characteristic curve (AUC) being 0.66 ( p = 0.002). Among patients with positive PD-L1 expression and negative neoadjuvant therapy (NAT), peripheral CD8 + /CD28 + T lymphocytes were 54% higher than those with negative expression ( p = 0.003), with the AUC being 0.68 ( p = 0.003). In patients receiving NAT, peripheral TNF-α ( p = 0.010), increased from 0.45pg/ml to 0.64pg/ml in positive PD-L1 group, and the AUC was 0.79 ( p = 0.012). Among breast cancer patients with negative NAT experience, 1% increase of peripheral CD8 + /CD28 + T lymphocytes was associated with a 21% higher probability of positive PD-L1 expression (OR = 1.21, 95%CI = 1.06–1.37) and among patients with NAT, the OR of peripheral TNF-α > 0.5pg/ml was increased to 24.5 for positive TME PD-L1 expression (p = 0.008). Conclusion In breast cancer patients receiving NAT, peripheral TNF-α could be used to predict the TME PD-L1 expression, and in breast cancer patients without NAT, peripheral percentage of CD8 + /CD28 + T lymphocytes could be used to predict the TME PD-L1 expression. These biomarkers should be further implemented in practice to guide the immunotherapy.