Precise Cancer Diagnosis from Blood with a Wearable Device

Capturing circulating tumor cells or DNA fragments in blood is one of the most important goals of precision oncology . In recent years, microchips in particular have been used in efforts to capture cancer cells. In this context, in April 2019, Nature published a study announcing the development of a wearable chip capable of capturing circulating tumor cells and screening the entire blood flow.

As is known, tissue biopsies are the method providing the most accurate results in detecting cancer. Biopsies are usually invasive (interventional) and can compromise patient comfort. Recently, as an alternative to tissue biopsies, the concept of liquid biopsy has emerged. Liquid biopsies are a heavily researched subject in oncology. They work by capturing cancer cells or cancer-related DNA fragments from a blood sample. In recent years, 3-dimensional smart microchips have been designed to capture these cancer cells in blood. Capturing such cells is particularly useful for understanding tumor biology and planning treatment. However, many problems with these smart microchips remain. A single blood sample is not sufficient to capture cancer cells.

To overcome this, researchers at the University of Michigan in the United States developed a wearable device that screens all the blood. Its features are quite different from previously developed microchips. Because this device is wearable, it can screen the entire blood flow .

The device is approximately 2.54 cm in size. As it will be implanted in the body, it is highly sterile and safe. It also contains a system to prevent blood clotting as blood passes through it. Blood entering the analysis mixes with heparin (a molecule that prevents clotting), preventing coagulation. The device’s filtration system contains graphene oxide and antibodies capable of capturing cancer cells. These specially designed antibodies can capture 80 percent of cancer cells.

To test the device, human cancer cells were injected into healthy dogs. It is important to emphasize that it was ensured that injecting cancer cells would have no long-term health effects in these animals. Because of tissue incompatibility, the dogs’ immune systems would eliminate the human cancer cells within a few hours of injection. Under standard conditions, the dogs were given sedatives (calming medications), and the devices were fitted after cancer-cell injection. Blood samples were also taken from the dogs every 20 minutes, and cancer cells in these samples were analyzed with the same device in the laboratory. This enabled comparison of the wearable chip with the laboratory chip. The wearable device was found to capture 3.5 times more cancer cells per milliliter than the same microchip in vitro (in the laboratory).

What Does This Study Mean for Us?

• A wearable device capable of capturing cancer cells circulating in blood was developed. This may be an important step for precision medicine and early cancer diagnosis .
• Most cancer cells cannot survive for long after entering the bloodstream. The few that survive in blood settle in other tissues, forming metastatic tumors. Therefore, capturing cancer cells in blood as early as possible is important for appropriate treatment planning and preventing spread to other tissues and organs. This device has significant potential for capturing such cells. 
• It is important to emphasize that this device is still being tested in the laboratory. A period of around 5 years is needed before human clinical trials can begin.
• LIQUID BIOPSIES IN CANCER for Those Who Want to Know More