Research progress on predictive value of immune cells in chemoradiotherapy for rectal cancer

Neoadjuvant chemoradiotherapy (NCRT) is the standard therapeutic strategy for locally advanced rectal cancer (LARC). Due to the different responses of patients to NCRT, the clinical prognosis of patients varies greatly. Therefore, it is important to establish sensitive biomarkers to predict the response of patients to treatments before NCRT. Immune cells in the tumor microenvironment (TME) were closely related to the efficacy of NCRT in patients with LARC. This paper reviewed the research progress on the relationships of cytotoxic T cells, programmed death-ligand 1 (PD-L1), tumor-associated macrophages (TAMs), regulatory T cells (Treg) and neutrophil to lymphocyte ratio (NLR) with chemoradiotherapy sensitivity in rectal cancer, illustrated the potential and limitations of these immune cells in predicting chemoradiotherapy response in rectal cancer, and provided a feasible direction for future researches.