Prognostic role of SOX2 and STAT3 expression on circulating T lymphocytes and CD44+/CD24neg cells in the locally advanced and metastatic breast cancer

Background Breast cancer (BC) is associated with a continuous increase in incidence, with high mortality rates in several countries. CD44, STAT3, and SOX2 are related to regulating of somatic cell division, tumorigenesis, and metastasis in BC. Methods A cross‐sectional study was carried out at the Hospital de Cancer de Pernambuco (HCP) between 2017 and 2018. Fifty‐one women with locally advanced (LA) and 14 with metastatic BC were included in the study. Results High CD44+/CD24 neg and CD44+/CD24 neg /SOX2+ levels in Luminal B (LB), HER2+, and triple‐negative breast cancer (TNBC) compared with controls ( p < 0.05). Low CD44+/CD24 neg STAT3+ levels in LB, HER2+, and TNBC compared with controls ( p < 0.05). High T lymphocytes, and low STAT3 + T, and SOX2 + T levels in BC patients ( p < 0.05). High SOX2 + T levels in patients with axillary lymph node‐negative (N0) compared with the axillary lymph node‐positives (N1 and N2 groups; p < 0.05). High SOX2 + T levels in N1 compared to N2 ( p < 0.05). High T lymphocytes and low SOX2 + T levels in the LA tumor compared to metastatic disease ( p = 0.0007 and p = 0.02, respectively). High CD44 + /CD24 neg STAT3+, and T lymphocyte levels in TNBC patients with LA tumor compared to metastatic ( p < 0.05). Low STAT3 + T levels in TBNC patients with LA tumor compared to metastatic ( p = 0.0266). Conclusion SOX2 and STAT3 expression on circulating T lymphocytes and CD44 + /CD24 neg cells in peripheral blood have prognostic roles in breast cancer. SOX2 and STAT3 expression are potential predictive biomarkers of disease progression in breast cancer regardless of tumor subtype.