The Role of Tumor-Associated Neutrophils in Early Luminal HER2-Negative Breast Cancer Progression.

OBJECTIVES

To study the predictive role of tumor-associated neutrophils in early luminal HER2-negative breast cancer.

MATERIALS AND METHODS

This is a retrospective study conducted on 60 women cases aged from 31 to 79 years underwent surgery for luminal HER2-negative ductal breast cancer in tertiary care cancer centre. We first estimated basic morphological signs: tumor size, tumor grade (by Nottingham Histologic Score), tumor infiltrating lymphocytes (TILs), Lymphovascular invasion, hormonal receptors status, proliferative index, and regional lymph nodes metastasis. The expression of intratumoral neutrophils was studied by CD15 immunohistochemistry which was performed using tissue microarrays. The total number of intratumoral neutrophils, were counted in 5 high-power fields.

RESULTS

According to the Nottingham histologic score system, grade I cases were detected in 10 cases (16%), grade II in 34 cases (57%), and grade III in 16 cases (27%). Lymphovascular invasion was determined in 23 cases (38%), and perineural invasion in 14 cases (23%). Number of TILs varied from 0 to 14 (counted in 5 HPF) and averaged 4.2±0.5. Luminal A tumor phenotype was detected in 35 cases (58%), and luminal B HER2-negative in 25 cases (42%). Nineteen (32%) women had metastases in regional lymph nodes (N+). The number of tumor microenvironment neutrophils in luminal HER2-negative breast carcinomas ranged from 1 to 10 (counted in 5 HPF) with an average value of 2.7±0.4. High tumor-associated neutrophils concentration significantly correlated with tumor size (<5mm and >20mm) with p=0.05, high grade (p=0.01), high proliferative index ((r=0.67; p=0.05), TILs (p=0.05), Lymphovascular space invasion (p=0.01)and positive regional lymph nodes metastasis (p=0.001), but not perineural invasion (p=0.1) and also, did not correlate with the expression of estrogen (r=0.18) and progesterone (r=0.14) receptors.

CONCLUSION

Tumor-associated neutrophils strongly predict a worse prognosis in early luminal HER2-negative breast cancer.