A new test capable of detecting a single cancer cell among a billion healthy cells in a small sample of blood is under development. Veridex, a Johnson and Johnson company, and Ortho Biotech Oncology Research & Development (ORD), a unit of Johnson & Johnson Pharmaceutical R & D have partnered with researchers at Massachusetts General Hospital (MGH, Boston, MA) to work on bringing the test to the market.
The initial prototype was developed by a team of doctors, engineers, and biologists led by Dr. Daniel Haber and Memhet Toner at Massachusetts General Hospital was first reported in 2007. The test detects circulating tumor cells (CTCs), cancer cells that break off from the tumor and get carried away in the blood stream. These CTCs are extremely rare, one may be detected for every billion normal healthy blood cells screened.
Haber and Toner have designed a CTC-chip that contains thousands of miniature pillars coated with antibodies that bind to CTCs. When a sample of blood is passed over the chip, the normal cells go through, but the CTCs stick. Specials stains then allow investigators to count the number of CTCs in a patient’s blood sample.
This test may be used to help doctors quickly make decisions about how to proceed when treating a patient’s cancer. If a doctor gives a particular drug and the number of cancer cells in the patient’s blood drops, then the doctor will stick with this treatment. If the number of cancer cells circulating in the blood increase or remain the same, the doctor can switch to another drug and which might work better at killing the cancer.
For example, doctors can give a drug or radiation treatment and then do a CT scan months later to see if the patient’s tumor has decreased in size. A patient may not live through more than a few rounds of treatment adjustment if they must wait to see if a change in tumor size can be detected. While the CT scan is a full body X-ray, the CTC-chip is simpler and only requires a few teaspoons of blood and can gauge whether the treatment was successful sooner.
The CTC-chip has been tested experimentally in approximately 200 cancer patients. A $15 million grant provided by the American Association for Cancer Research (AACR) Stand Up to Cancer telethon will enable investigators at four major research institutions to study the test in more cancer patients. These institutes include: Massachusetts General Hospital (Boston, MA), University of Texas M.D. Anderson Cancer Center (Houston, TX), Dana-Farber Cancer Institute (Boston, MA), and Memorial Sloan-Kettering Cancer Center (New York, NY).
Right now the chip is expensive (approximately $500) and requires expertise to use. The collaboration with Johnson and Johnson will help MGH investigators find ways to make the chip faster, cheaper, more sensitive, and easier to use by physicians. Hopes are high. This chip may change the way cancer is diagnosed and treated in the near future.