There are almost 10 million cancer survivors in the United States. Receiving the news that cancer has recurred and spread after having been given a clean bill of health is shocking and bewildering to most, and oftentimes more psychologically devastating than the original cancer diagnosis.
Many people react with fear when given the news about their metastatic cancer, others with anger, and some with a sense of utter hopelessness. When breast, colorectal, or prostate cancer becomes metastatic, it immediately raises numerous concerns and important, questions. What is the best therapy? How do I make the treatment choice? Should I consider joining a clinical trial?
Many recurrent cancer treatment choices are based on how the disease is progressing. To determine this, doctors look for signs, which are traditionally provided by imaging or tumor marker tests at certain points during therapy.
Now there is another option: use of a new technology to measure circulating tumor cells (CTCs) in a sample of blood to aid in the early detection of rogue cancer cells in patients with recurrent cancer. This is a different kind of test that can help people learn how their therapy is working much sooner. The technology allows patients to monitor their progress at any point along their treatment course, and guides the doctor in adjusting therapy as needed.
CTCs are cancer cells that have broken away from an existing tumor cell and have entered the bloodstream. The presence of these cells in the blood can provide valuable insight into the progression of the cancer. Clinical studies of patients with metastatic cancers of the breast, colon/rectum, or prostate have reported that the monitoring and detection of CTCs can actually predict whether a patient’s prognosis is more or less favorable.
This blood test captures, identifies, and counts CTCs in a tube of blood. Using a predetermined cutoff number—5 CTCs for metastatic breast and prostate cancer; 3 CTCs for metastatic colorectal cancer—the test can specifically predict a patient’s probable outcome.
“This technology has enormous promise,” says Daniel F. Hayes, M.D., Clinical Director of the Breast Oncology Program at the University of Michigan Comprehensive Cancer Center in Ann Arbor. “I regularly use it in my clinic. In the end, the benefit of this technology is that it will give us a snapshot of what cancer is doing right now without having to biopsy the patient. That is the real hope and excitement that this test offers.”
Where Are They Now
Circulating tumor cells (CTCs) are cancer cells that have detached from an existing tumor cell and have entered the bloodstream. Measuring CTCs in a sample of blood can facilitate early detection of recurrent cancer in patients who are known to have the disease. This technological advance helps in understanding response to therapy much sooner, allowing patients to monitor their progress at any point along their treatment course, and guiding the doctor in adjusting therapy as needed.
The FDA has approved the use of CTC detection to monitor treatment effects in breast, colorectal, and prostate cancers, while other applications are under active development. A new, FDA approved device has the ability to isolate CTCs of lung, prostate, melanoma and breast cancer, etc. and culture them for more efficient use in drug testing, giving doctors increased knowledge of which drugs will be the most effective for each patient to improve patient outcomes. In a 2016 forecast report, Circulating tumor cell technology is expected to grow to touch a $22 million figure as the prevalence of cancer in a growing population becomes a prominent issue. The detection aspect of CTCs remains the biggest challenge to date as a demand for a technology that detects real metastasis-initiating CTCs remains unfulfilled by the existing technology despite continued development.