Liquid Biopsy in Cancer: Focus on Lymphoproliferative Disorders

SIMPLE SUMMARY: Liquid biopsy (LBx) is a novel and promising approach in precision medicine, suitable for patient management in a wide range of medical conditions. Its utility in oncology ranges from disease screening to early diagnosis and treatment. LBx has several strengths, such as safeness, quickness of execution, and repeatability, compared to old-fashioned solid biopsy techniques; indeed, LBx requires the collection of a small number of biospecimens. LBx has been proven to be accurate and reliable, as demonstrated in several clinical studies, and it could have a surprising impact on survival and quality of life for cancer patients in the near future. With the present review article, we aim to summarize LBx characteristics, considering both the clinical and the laboratory settings; and to collect the most recent evidence within the oncology field, with a specific focus on blood cancers. ABSTRACT: Within the context of precision medicine, the scientific community is giving particular attention to early diagnosis and intervention, guided by non-invasive methodologies. Liquid biopsy (LBx) is a recent laboratory approach consisting of a non-invasive blood draw, which allows the detection of information about potential prognostic factors, or markers to be used for diagnostic purposes; it might also allow the clinician to establish a treatment regimen and predict a patient’s response. Since the discovery of circulating tumor cells (CTCs) in the nineteenth century, the possibility of integrating LBx into clinical practice has been explored, primarily because of its safeness and easy execution: indeed, compared to solid biopsy, sampling-related risks are less of a concern, and the quickness and repeatability of the process could help confirm a prompt diagnosis or to further corroborate the existence of a metastatic spreading of the disease. LBx’s usefulness has been consolidated in a narrow range of oncological settings, first of all, non-small cell lung carcinoma (NSCLC), and it is now gradually being assessed also in lymphoproliferative diseases, such as acute lymphocytic leukemia (ALL), B-cell lymphomas, and multiple myeloma. The present review aims to summarize LBx’s overall characteristics (such as its advantages and flaws, collection and analysis methodologies, indications, and targets of the test), and to highlight the applications of this technique within the specific field of B-cell malignancies. The perspectives on how such a simple and convenient technique could improve hemato-oncological clinical practice are broadly encouraging, yet far from a complete integration in routine clinical settings.