Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 0 0 2026 04 11 1 14 Li Dong Department of General Surgery, Hongqi Hospital Affiliated to Mudanjiang Medical University, Mudanjiang, China Yue Zhao Clinical Laboratory, The Second Affiliated Hospital of Mudanjiang Medical University, Mudanjiang, China Yuqi Sun Clinical Laboratory, The Second Affiliated Hospital of Mudanjiang Medical University, Mudanjiang, China Fuxin Cui Clinical Laboratory, The Second Affiliated Hospital of Mudanjiang Medical University, Mudanjiang, China 2025 06 26 2025 11 24 Breast cancer is a leading malignancy in women. Understanding its clinicopathological traits and microsatellite status is vital for prognosis and treatment planning. This study explored the links between preoperative pan-immune-inflammation value (PIV) and hemoglobin, albumin, lymphocyte, and platelet (HALP) score with breast cancer’s pathological features and microsatellite status and assessed their predictive power for the latter. This retrospective study analyzed data from 260 breast cancer patients who had surgery between 2022 and 2025. Researchers not involved in the patients’ treatment collected and analyzed the data. HALP and PIV were calculated from preoperative blood tests. Patients were grouped based on the median values of these scores. Associations between the scores and clinicopathological characteristics were examined. Patients were also divided into microsatellite stable (MSS) and microsatellite instability-high (MSI-H) groups, and differences in HALP and PIV between these groups were compared. Receiver operating characteristic curves were used to evaluate the predictive accuracy of HALP and PIV for microsatellite status. High PIV was linked to younger age and lower ER positivity. High HALP correlated with older age, a higher proportion of clinical stage I patients, and lower HER2 positivity. MSS patients had lower PIV and higher HALP than MSI-H patients. PIV and HALP showed significant correlations with microsatellite status. Both indicators had high AUC values (PIV: 0.867; HALP: 0.879), with 100% sensitivity, indicating strong predictive capabilities. Preoperative PIV and HALP are closely tied to breast cancer’s pathological features and microsatellite status. They offer high predictive value for microsatellite status, aiding in breast cancer diagnosis and treatment decisions.  https://ijaai.tums.ac.ir/index.php/ijaai/article/view/4497 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/4497/2319