Relevance between lymphocyte infiltration in breast cancer and prognosis

Abstract

Globally breast cancer is the most common cancer, and the second most common cause of death just behind lung cancer in women and the most common cause of death in women ages 45-55 years. Tumor-infiltrating lymphocytes (TILs) play an essential role in mediating response to chemotherapy and improving clinical outcomes which opens the possibility for new treatment options through modulation of immune response. TILs have been shown to provide prognostic and potentially predictive value, particularly in triple-negative and human epidermal growth factor receptor 2-overexpressing breast cancer but their role and the effect of TILs on prognosis in luminal breast cancer is less clear. We therefore evaluated relationship between TILs and clinical outcome in patient with all subtypes of breast cancer. The primary clinical outcome was defined as disease-free survival(DFS) and overall survival. Methods and materials: Paraffin blocks (biopsies) from patients with primary breast cancer except for metastatic cases who have been operated and confirmed by pathology were included and assessed by H&E staining for number of TILs. Clinical information, status of hormone receptor (Estrogen Receptor and Progesterone Receptor), HER2 and disease stage using TNM method assessed and collected. The patients DFS and OS in all subtypes of breast cancer were evaluated. We used these data in invariable and multivariable statistical models to assess the relevance between TILs DFS and OS. Results: A total of 228 patients with breast cancer except for metastatic cases in the period of 10 years (2009 – 2019) who were followed by October 2022 were enrolled. 134 patients (58.8%) had TILs (TILs positive). The mean of TILs were 23.29% +-15.77%. TILs connection with the age and stage was not statistically significant. P-value was respectively 0.613 and 0.272. TILs connection with the subtype of breast cancer was statistically meaningful (P-value <o.oo1). The effect of the TILs on DFS and OS was reviewed and did not see a meaningful relevance. The effect of the TILs on DFS and OS was investigated in breast cancer subtypes and no significant relevance was observed in any subgroups. Survival of 2, 5 and 10 years for DFS was estimated. The values were respectively 99.6% , 94% and 80.1% . Survival of 2, 5 and 10 years for OS was estimated. The values were respectively 99.6%, 97.6% and 82.9%. In subgroups of TILs, age , subtype and stage DFS and OS survival also calculated and compared which was not significantly different in the data in any of subgroups.