Background: Breast cancer (BC) is the most common cancer worldwide and is the main cause of cancer related death in women. Forkhead boxp3(FOXP3) is a transcription factor that plays an important role in the development and function of immune regulatory T cells (Tregs). A strong relation between the COX-2/PGE2 pathway and FOXP3-positive Tregs has been proposed.
Objective: We implemented this study to evaluate the prognostic significance of FOXP3 and COX-2 expression and relation with overall survival in BC patients.
Patients and Methods: This study was conducted on archival cases of 66 BC patients. Tumor infiltrating lymphocytes was evaluated in H&E slides whether peri-tumoral or intra-tumoral and were classified as absent, low, moderate, and high infiltration. Sections from each case were stained for FOXP3 and Cyclo-oxygenase 2(COX2). Expression of FOXP3 was assessed in malignant epithelial tissues and in tumor infiltrating lymphocytes (intra-tumoral and peri-tumoral). Expression of COX-2 was assigned in tumor epithelial cells and correlated with overall survival.
Results: Higher FOXP3 H. scores in epithelial cells were associated with younger age, low grade tumors, non-triple negative group. Higher FOXP3 H. scores in peri-tumoral lymphocytes were significantly associated with young age. Higher H. scores of COX2 expression was associated with PR negative cases. OS was improved in patients with high infiltration by peri-tumoral infiltrating lymphocytes and high FOXP3 positive intra-tumoral lymphocytes scores.
Conclusions: Dense TILs as well as high FOXP3 expression are considered as good prognostic factors. On the other hand, COX2 might be considered to have poor prognostic role.