Circulating Cancer Cells: Why We All Have Them and How We Fight Them Off

Circulating tumor cells (CTCs) are cancerous cells that have broken away from a tumor and ejected into the bloodstream. These CTCs can be found in any bodily fluid such as blood, urine, saliva and cerebrospinal fluid. CTCs were first discovered by Dr. John Dick in 1964 when he noticed these cells after injecting mice with leukemia.

Do I Have CTCs?

Everyone has CTCs circulating in our bodies; this means CTCs can be found in cancer patients and those who are perfectly healthy. Our bodies fight off circulating tumor cells by surrounding CTCs with healthy cells that emit a signaling protein called Tumor necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL), which causes CTCs to die.

However, cancerous tumors produce CTCs that often have mutations that help them resist being killed off by circulating immune cells. Thus, CTCs are often linked to cancerous tumors or metastasized cancers as they can indicate how advanced a cancer is or if it has spread throughout the body by traveling through the bloodstream.

CTC testing is a valuable tool for doctors to detect and diagnose various cancers early by examining the CTC count or cell morphology.

How Does the Presence of CTCs Help Diagnose Cancer?

Cancers are often difficult to detect early on because they do not always have symptoms that lead them to be diagnosed until after it has spread or metastasized throughout the body. CTCs allow researchers and doctors to detect cancer earlier than ever before, which may eventually revolutionize how deadly diseases can be treated. CTCs can be found in the blood of cancer patients, and CTC counts are often used as an indicator for how advanced a tumor is or if it has metastasized to other parts of the body. This allows doctors to track patient progress more efficiently than traditional CT scans, MRIs and physical exams, which only allow physicians to detect cancer once the disease is more advanced.

For years, CTC research has been used to detect various cancers, including lung cancer, the most common type of cancer diagnosed using this method. Treatment for CTCs is still being researched, but many experts believe it could lead to an early detection system for detecting cancers before they spread through the body. CTCs are important in research because they can provide vital information on the cancer stage, how fast it spreads and whether treatment is working. CTCs also give researchers a window into what may be lurking undetected in other parts of the body that have yet to become symptomatic.

More than a thousand men and women diagnosed with cancer each year turn to our trusted team of cancer specialists. We encourage you to call us, ask us a question, or consult with us to get a second opinion so you, too, can experience the difference.