Biomarkers in hematological malignancies: A narrative review of diagnostic, prognostic, and predictive applications

Hematological malignancies represent a significant challenge in both diagnosis and treatment, constituting a substantial portion of global cancer cases. The integration of biomarkers into the diagnostic and therapeutic processes is essential but remains underexplored in the context of precision medicine. This review synthesizes the current literature on established and emerging biomarkers, including monoclonal immunoglobulins, beta-2 microglobulin, cytogenetic and molecular markers, and liquid-biopsy-based markers, and their diagnostic, prognostic, and predictive applications across leukemia, lymphoma, and multiple myeloma. We describe how these biomarkers are used in current clinical practice to support diagnosis, risk stratification, and treatment selection, based on the published evidence base for each marker. Overall, validated biomarkers have improved diagnostic accuracy, risk stratification, and therapeutic decision-making, while emerging biomarkers require further clinical validation. Although several biomarkers are now incorporated into routine clinical care, ongoing validation of emerging biomarkers will be critical for expanding precision oncology approaches in hematologic malignancies.