Can TILs be associated with prognostic factors and survival rates in breast cancer? A retrospective analysis

Introduction: The relationship between the tumor inflammatory infiltrate, also known as tumor-infiltrating lymphocytes (TILs), and invasive breast carcinomas has been extensively studied in recent years to verify its association with prognosis and response to treatment. The goal of this study was to associate the presence of TILs with patient's survival time. Methods: We studied prognostic clinicopathological characteristics already established in the literature and their impact on overall five-year survival time of patients with invasive breast cancer treated at Hospital Santa Casa in Belo Horizonte, Minas Gerais, Brazil, in 2011 (n=290). This was an observational and retrospective study. Results: The presence of TILs was associated with tumors of no special type (p=0.018) and with younger age of the patients (p=0.042). Smaller tumor size (HR: 19.24; 95%CI 4.30­86.15; p<0.001), absence of metastasis to the axillary lymph nodes (HR: 2.80; 95%CI 1.02­7.70; p=0.002), positivity for progesterone receptor (HR: 0.39; 95%CI 0.17­0.87; p=0.022), and presence of TILs (HR: 0.23; 95%CI 0.08­0.65; p=0.005) were associated with longer survival times. Conclusions: This study suggests that the presence of TILs, along with other clinicopathological characteristics, is a prognostic factor in breast cancer