Association of p53 Expression with Tumor-Infiltrating Lymphocytes in Invasive Breast Carcinoma: An Immunohistochemical Study

Abstract

Objective: Breast carcinoma is one of the most common malignancies affecting women worldwide. Tumor-infiltrating lymphocytes (TILs) represent an important component of the tumor microenvironment and have been associated with prognosis and therapeutic response in breast cancer. The tumor suppressor protein p53 plays a crucial role in cell cycle regulation, apoptosis, and genomic stability. The present study aimed to evaluate p53 expression in invasive breast carcinoma and determine its association with stromal tumor-infiltrating lymphocytes. Methods: This retrospective study included 30 cases of invasive breast carcinoma of no special type. Immunohistochemical staining for p53 (Clone DO-7, DAKO) was performed and graded based on the percentage of positive tumor nuclei. Stromal TILs were assessed on hematoxylin and eosin-stained sections according to the recommendations of the International Immuno-Oncology Biomarker Working Group and categorized into three grades based on the percentage of stromal involvement. Statistical analysis was performed using Pearson’s chi-square test, with p<0.05 considered statistically significant. Results: Among the 30 cases, p53 expression was Grade 2 in 19 cases (63.3%), Grade 1 in 10 cases (33.3%), and Grade 0 in 1 case (3.3%). Stromal TILs were Grade 3 in 10 cases (33.3%), Grade 2 in 14 cases (46.7%), and Grade 1 in 6 cases (20%). A statistically significant association was observed between increased p53 expression and stromal TIL grade (p = 0.0297). Conclusion: The study demonstrates a significant association between p53 expression and stromal TIL levels in invasive breast carcinoma, suggesting a relationship between TP53-related tumor biology and the host immune response. Further studies with larger sample sizes are warranted to validate these findings.