Locally advanced rectal cancer, Neoadjuvant chemotherapy, Overall survival, Prognosis, Tertiary lymphoid structures, Surgery, RD1-811, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282

Abstract Background The tertiary lymphoid structures (TLSs) are positively correlated with the prognosis of many solid tumors, including colorectal cancer. However, their prognostic significance in patients with locally advanced rectal cancer (LARC) after neoadjuvant chemotherapy remains unclear. This study aimed to explore the correlation between TLS parameters and the prognosis of LARC patients receiving neoadjuvant chemotherapy. Methods This retrospective study included patients with LARC treated at the Harbin Medical University Cancer Hospital from 2012 to 2021. The quantity, area, and density of TLSs in the tumor, normal, and total tissues from surgical specimens were determined. Overall survival (OS) was calculated from surgery to death from any cause. The correlation between TLS parameters and prognosis was assessed using Kaplan-Meier survival analysis and Cox regression analysis. Multiplex immunofluorescence (mIF) staining was used to analyze TLS maturity and immune composition. Results This study included 114 patients, of whom 46.5% were over 60 years old, and 70.2% were male. TLS parameters in tumor region were smaller than those in normal and total regions (P