Assessment of the association of FOXP3 positive tumour infiltrating lymphocytes with therapeutic response in triple negative breast cancer. (360G-Wellcome-202144_Z_16_Z)

Tumour infiltrating lymphocytes (TILs) have been shown to be associated with a positive therapeutic response in triple negative breast cancer (TNBC). However TILs can have both pro-tumour and anti-tumour properties. It is thought that FOXP3 expression in TILs can downregulate their ability to target and inhibit tumour cells. In this proposed summer project, we will assess the levels of TILs in a cohort of 383 patients with triple negative breast cancer who specimens are arrayed on a tissue microarray. The cohort includes 100 cases treated with neoadjuvant therapy and 283 with adjuvant therapy. We will further assess the phenotype of the TILs using FOXP3 immunohistochemistry to determine the levels of FOXP3 positive TILs in TNBCs. We will then correlate TILs and FOXP3+TILs with histological subtype, tumour stage at diagnosis, tumour grade at diagnosis using logistic regression and chi square analysis. Additionally we will assess the ability of TILs and FOXP3+TILs to predict response to adjuvant therapy, and assess if tumours with which did not respond to neoadjuvant therapy possess increased levels of FOXP3+TILs.