Liquid Biopsy: New Kid on the Block

Abstract

Cancers have historically been diagnosed by gold-standard invasive procedures, such as an open biopsy, CT, or US guided needle biopsy. These procedures provide pathologists with adequate tissue specimens to conduct routine histopathology (H&E stain), specialized tests such as immunohistochemistry and submit tissue for genetic analysis, molecular studies, and flow cytometry. This has translated into a need for larger specimens. Over the past years, there has been an emerging need for less invasive or minimally invasive procedures in surgical and oncologic specialties. This has resulted in the much acclaimed, revolutionary, noninvasive, or minimally invasive technique, Liquid Biopsy, a boon to oncologists much appreciated by the patient population. In this era of “precision,” “personalized,” or “point of care” medicine, there are major advancements in not only diagnostic methodologies but also in prognostic and therapeutic modalities. This allows the treating physicians to work with less material obtained by a non-invasive or minimally invasive procedure. However, it is important to note that this innovative testing modality does not replace the gold standard tissue diagnosis. Liquid Biopsy, however, provides an excellent practical, complement, or on occasion an alternative, procedure for obtaining sequential samples for molecular testing. It allows for real-time monitoring of the cancers as it provides a snapshot of the primary and/or metastatic tumor, allowing for personalized treatment options. Liquid Biopsy can change the prognostic and predictive landscape for cancer genotyping, impacting patient management. In this review article, the authors will provide a simplified overview of the various aspects of Liquid Biopsy, including its pros, cons, clinical applications, current role, and future potential in healthcare. We hope to provide new insights that will enhance the current understanding of Liquid Biopsy as it stands today and how it may shape future patient care.