Significance of tumor-infiltrating lymphocytes in tumor regression in breast cancer: A study in a tertiary care cancer center in South India.

Background: Tumor immunology plays a significant role in predicting tumor biology and how a tumor is going to respond to neoadjuvant chemotherapy (NACT). Tumor-infiltrating lymphocytes (TILs) are the easiest and by far the cheapest method of assessing tumor immunity. Many studies have suggested that TILs play an important role in tumor regression in breast cancer.