Circulating tumor cells (CTCs)—important markers of distant metastasis1

Tumors metastasize, or spread, when they detach from the primary tumor and enter into the bloodstream, which in turn transports the cells to distant sites, such as bones, liver, brain, and lungs. Tumor cells detected in the blood stream are referred to as CTCs. Once they have traveled to a distant site, some of these cells may establish new tumors in these sites, a process known as metastasis.1

Frequency of CTCs in Healthy Controls vs Patients with Metastatic Breast (mBC), Colorectal (mCRC), and Prostate (mPC)* Cancers2

CTCs are rarely found in healthy people or in people with nonmalignant tumors. Among 295 healthy controls (with or without benign tumors), only 3% had >1 CTC detected in blood samples analyzed by the CELLSEARCH® Circulating Tumor Cell Test.2

Conversely, in patients with metastatic breast, prostate, or colorectal cancer, CTCs were consistently and markedly more prevalent.2

Learn about the clinical relevance of the CELLSEARCH® CTC Test
Review clinical trial data and real-world case studies showing the role of CTC testing in patient management

*Metastatic prostate cancer patients were defined as having two consecutive increases in the serum marker prostate-specific antigen above a reference level, despite standard hormonal management. These patients are commonly described as having androgen-independent, hormone-resistant, or castration-resistant prostate cancer. For more information on the intended use and limitations for the CELLSEARCH® Circulating Tumor Cell Test, please refer to the Instructions for Use which can be found at

  1. Yu M, Stott S, Toner M, Maheswaran S, Habor DA. J Cell Biol. 2011;192(3):373-382.
  2. CELLSEARCH® Circulating Tumor Cell Kit (Epithelial) Instructions for Use. Menarini Silicon Biosystems Inc.