3D hydrogel biochips offer better diagnosis of early-stage bowel cancer
Early detection is paramount to survival from bowel cancer, but doing so is difficult because most symptoms don't present until the cancer matures. Worse, existing diagnostic tests tend to be invasive and traumatic. Russian scientists hope to change this with a new biochip technology that can gather better, more precise data for diagnostic analysis. The scientists report that their new method far outstrips traditional methods of diagnosing bowel cancer.
Bowel cancer, which is also known as colorectal cancer, is the third most common cancer in the world, and the fourth most deadly. It is treatable, but survival rates drop dramatically with each stage of the disease. In the scientists' native Russia, the five-year survival rate for people diagnosed with the disease is just 41 percent, while worldwide it was greater than 60 percent in only 22 countries between 2005 and 2009.
In an effort to improve the chances of early diagnosis, scientists from several Russian research centers proposed a new method that detects autoantibodies – antibodies that form automatically at the early stages of cancer and that target and damage specific tissues or cells.
They are specifically interested in autoantibodies against tumor-associated glycans, which are sugary compounds like chitin and cellulose. Glycans are essential for building and maintaining cells, as well as in enabling communication between cells. Cancerous glycans spread the disease, and the immune system produces specific autoantibodies to fight against these.
The researchers created 3D (hemispherical) hydrogel-based biochips, 3D cells made of a special gel that contains the molecular probes needed to gather data from blood serum. By opting for a 3D biochip structure rather than a flat one, they could get equal distribution of probes and thereby make a more accurate reading.
They tested their system on the sera of 129 people, 33 patients with colorectal cancer, 27 with inflammatory bowel disease, and the rest healthy donors. The biochip method was able to diagnose colorectal cancer in 95 percent of cases, compared to 79 percent with traditional methods. And it had a sensitivity reading of 88 percent versus just 21 percent for detecting the cancer in stage II or later patients (which means it more accurately determined who still had the cancer).
The scientists hope this new screening and early detection method could provide a more reliable and cheaper alternative than existing techniques such as colonoscopy, which lean more into cancer prevention than cancer detection and which are also more invasive than the biochip method.
They now plan to verify their findings with further investigation.
A paper describing the study was published in the journal Cancer Medicine.