Clinical application of PBMCs in breast cancer: detection, treatment evaluation and prognosis

Breast cancer (BC) has superseded lung cancer as the most prevalent malignant neoplasm globally, posing a significant threat to human health. Currently, mammography and ultrasonography serve as the primary modalities for early breast cancer screening. However, X-ray examination exhibits low sensitivity, while ultrasonography has a high false positive rate, which can readily lead to overdiagnosis and overtreatment. Peripheral blood mononuclear cells (PBMCs), which are specialized immune cells generated by hematopoietic stem cells (HSCs), actively monitor any indications of infection, foreign invaders, and abnormal or aberrant cells associated with diseases. Given that PBMCs respond to diverse pathophysiological stimuli in the form of immune responses/immune phenotypic changes, the study of the molecular constituents of PBMCs can facilitate a better understanding of the immune process. Simultaneously, as PBMCs can be isolated from peripheral blood and detected in liquid form, they offer a non-invasive and suitable source of biomarkers. The analysis of PBMCs in cancer patients can be utilized for the early screening and diagnosis of breast cancer, as well as for evaluating therapeutic efficacy and prognosis. This article reviews the clinical application of PBMCs in breast cancer, highlighting its advantages and limitations.