Context: Breast cancer constitutes nearly one third of cancers among women. Immune responses caused by neoplastic cells lead to the accumulation of inflammatory cells like mast cells (MCs), macrophages, lymphocytes, and plasma cells around the tumor tissue forming the tumor microenvironment.
Aim: The study aims at quantifying the role of MCs in different grades of invasive carcinoma of breast with respect to estrogen receptor (ER), progesterone receptor (PR), and Human Epidermal growth factor Receptor 2 (HER2/neu).
Materials and methods: This study included 60 cases of invasive carcinoma of breast. Toluidine blue staining was used for quantitative MC analysis and correlated with immunohistochemistry analysis for hormonal markers' positivity-ER, PR and HER2/neu.
Results: The mean age was 52 years (range: 25-75 years). The average number of MCs in Grade I, II, and III were 24.05, 18.4, and 7.9, respectively, with a significant P value. ER, PR, and HER2/neu positivity was found in 60%, 55%, and 32% of the cases, respectively. ER positivity with mean MC count of 23.55 was found in 36 cases, and 33 cases were positive for PR with a mean MC count of 24.18 and a significant P value. HER2 positive cases were 28 with a mean MC count of 20.82.
Conclusion: The presence of MCs in breast cancer is inversely proportional to the grade of tumor, i.e., a maximum number of MCs were seen in low grade tumors. In addition, there is a positive correlation between ER and PR receptor positivity with the presence of MCs in the stroma of breast cancer.
Keywords: Breast cancer; invasive ductal carcinoma; mast cell; toluidine blue; tumor microenvironment.