Bone Marrow Infiltration in Breast Cancer: Diagnostic and Prognostic Perspectives- A Narrative Review

Abstract

Bone marrow infiltration (BMI) by breast cancer cells is an early and critical step in the metastatic cascade that significantly impacts patient prognosis. The bone marrow microenvironment serves as a sanctuary for disseminated tumor cells, allowing them to survive, evade treatment, and potentially lead to disease recurrence. Understanding the mechanisms and clinical significance of BMI is essential for improving detection and therapeutic strategies in breast cancer management. Diagnostic approaches for identifying BMI range from invasive techniques such as bone marrow biopsy with histopathological and immunocytochemical analysis, to emerging molecular assays that increase sensitivity for detecting isolated tumor cells. Conventional imaging modalities provide limited sensitivity for early marrow involvement, underscoring the need for more precise diagnostic tools. Advances in molecular diagnostics and liquid biopsy technologies hold promise for less invasive and more accurate detection of bone marrow micro metastases. The presence of BMI in breast cancer patients is strongly associated with poorer outcomes, including increased risk of relapse and reduced overall survival. As a marker of minimal residual disease, BMI assessment can inform prognosis and guide personalized treatment decisions, including the escalation of adjuvant therapies. Integrating bone marrow evaluation into clinical practice and further elucidating tumor-microenvironment interactions could enhance metastasis prevention and improve long-term patient outcomes. Keywords: Bone marrow infiltration, breast cancer, metastasis, diagnostic methods, prognostic markers