A circulating tumor cell (CTC) is a cell that has shed into the
vasculature or
lymphatics from a primary
tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
and is carried around the body in the
blood circulation
The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...
. CTCs can
extravasate and become ''seeds'' for the subsequent growth of additional tumors (
metastases
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, the ...
) in distant organs, a mechanism that is responsible for the vast majority of cancer-related deaths. The detection and analysis of CTCs can assist early patient prognoses and determine appropriate tailored treatments.
Currently, there is one FDA-approved method for CTC detection, CellSearch, which is used to diagnose
breast
The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues.
In females, it serves as the mammary gland, which produces and s ...
,
colorectal
The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the digestive system in tetrapods. Water is absorbed here and the remaining waste material is stored in the rectum as feces before being rem ...
and
prostate
The prostate is both an accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found only in some mammals. It differs between species anatomically, chemically, and phys ...
cancer.
The detection of CTCs, or
liquid biopsy, presents several advantages over traditional tissue biopsies. They are non-invasive, can be used repeatedly, and provide more useful information on metastatic risk, disease pro