Liquid Biopsy for Cancer: Review and Implications for the Radiologist

Abstract

R adiologists play a pivotal role in cancer care through imaging for the purposes of screening, diagnosis, treatment planning, and surveillance. Additionally, image-guided tissue biopsies performed by radiologists allow for more specific diagnosis and the ability to molecularly characterize tumor cells. Radiologists are also involved in cancer treatment as interventional radiologists deliver minimally invasive local-regional therapies and nuclear medicine physicians administer radionuclide therapy. As discussed by Hricak (1), there are many exciting developing advancements in the field of radiology in the context of precision oncology. Although characterizing physiologic and molecular features of tumors through imaging has traditionally been limited to enhancement characteristics and metabolism, deeper tumor characterization is now possible through molecular imaging for treatment selection, dose finding, and data acquisition on tumor metabolism through nuclear medicine and MR spectroscopy. These innovations, combined with the integration of artificial intelligence and the emerging fields of theranostics and radiomics, are just a few of the ways that radiologists are expanding their contributions and adding value to the care of the patient with cancer (1,2).The emergence of precision medicine and personalized cancer treatment based on genetic analysis of tumor tissue over the past few decades has resulted in more specific treatment options. While tumor cell receptors, driver mutations, and treatment-susceptible alterations allow for tailored treatment selection, cancers continue to adapt through genetic and epigenetic alterations and acquire resistance to therapy (3). Intratumor heterogeneity

Identification of a Two-MicroRNA Signature in Plasma as a Novel Biomarker for Very Early Diagnosis of Breast Cancer

“…Recent studies proposed liquid biopsy as a valuable procedure for cancer detection that might complement current clinical tools, improving not only diagnosis but also treatment monitoring [ 28 ]. The most studied biomarkers present in the bloodstream by cancer cells are circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), circulating miRNAs, extracellular vesicles (EVs), and exosomes [ 29 ].…”

Enhanced Lipid Metabolism Induces the Sensitivity of Dormant Cancer Cells to 5-aminolevulinic acid-based Photodynamic Therapy

“…These ndings suggest that lipid metabolism in tumors may be predictive of ALA-PDT e cacy. Biopsy is a standard method for con rming cancer cells in tumors [44,45]. Immunostaining of ACSs or other lipid metabolism-related gene in biopsied specimens could have predictive utility.…”

Do we still need breast cancer screening in the era of targeted therapies and precision medicine?

“…Dedicated algorithms will focus on personalised risk prediction and prognosis [81] and machine/deep learning software has already shown high performance in interpreting screening mammography. Finally, the availability of molecular analyses on liquid biopsy could represent another promising option [82,83].…”