Liquid biopsy in blood cancer

In recent years, liquid biopsy using cell-free DNA (cfDNA) has gained significant traction in the field of oncology, especially in malignant hematology. This chapter provides a historical review of cfDNA analysis and describes the biology of cfDNA and concepts in the technical evaluation of cfDNA in cancer. In the second part of the chapter, we focus on cfDNA analysis in specific hematologic malignancies, including acute lymphoblastic and myeloid leukemias, classical Hodgkin and non-Hodgkin lymphomas, and multiple myeloma. Cell-free DNA consists of tiny fragments of DNA present in the peripheral blood through active and passive processes. It has a short half-life, and only a minute amount is present in the peripheral blood. Due to its unique characteristics, multiple technical considerations must be addressed, including collection, processing, storage, and sample analysis. Various polymerase chain reaction and next generation sequencing methods can be used for cfDNA analysis, and each method has its advantages and limitations. A liquid biopsy can be easily obtained through a routine venipuncture, making it an attractive tool in diagnosis, prognostication, and minimal residual disease monitoring of hematolymphoid malignancies.