3-D hydrogel biochips detect bowel cancer at early stages

01/06/2016

Researchers from the Moscow Institute of Physics and Technology (MIPT), the Engelhardt Institute of Molecular Biology (EIMB RAS), the Institute of Bioorganic Chemistry (IBCh) and a number of other Russian research centers have developed a new method of diagnosing colorectal cancer. The results of the study have been published in Cancer Medicine.

Photo: A number of small glass vials in a rack in the lab

Researchers from a number of Russian research centers have developed a new method of diagnosing colorectal cancer. The scientists have created a hydrogel-based biochip to help detect bowel cancer i.e. colorectal cancer; ©MIPT

The scientists have created a hydrogel-based biochip to help detect bowel cancer i.e. colorectal cancer (CRC). CRC is the third most common type of cancer and it develops with minimal clinical symptoms in the early stages. Despite doctors' efforts, the 5-year survival rate does not exceed 36 percent. Treatment is only effective, and patients only have a good chance of recovery, if the cancer is detected early.

Diagnostic methods that are currently in use are not sufficient. Analyses carried out in vitro have low specificity and invasive studies such as colonoscopy are not only traumatic, but they are also not always suitable for an early diagnosis, as they do not give a complete picture of the development and distribution of colorectal cancer.

The method proposed by scientists from EIMB RAS, MIPT, the Russian Scientific Center of Surgery, Sechenov First Moscow State Medical University, the Institute of Bioorganic Chemistry, and Buyanov City Clinical Hospital is based on the simultaneous detection of various substances in patients' blood. These substances are autoantibodies against tumor-associated glycans, which can be found in serum at the early stages of cancer, immunoglobulins of different classes, and oncomarkers, molecules produced by tumor cells.

The researchers developed a model of the test-system which is able to simultaneously measure the concentration of protein-based oncomarkers, the autoantibodies-to-glycans ratio, and immunoglobulins IgG, IgA, and IgM in a patient's blood. Taking into account the fact that most protein-based markers are not specific in terms of the location and type of the tumor, scientists divided them into groups - diagnostic and prognostic signatures, combinations of protein-based oncomarkers and antibodies to glycans etc.

Using the model, the scientists analyzed the sera of 33 patients with colorectal cancer, 69 healthy donors and 27 patients with inflammatory bowel disease. Cases like Crohn's disease and diverticulitis may in the long term lead to colorectal cancer, however, they should not be confused with one another when diagnosing the disease - the laboratory analysis system needs to not only be sensitive, but also precise.

This method surpasses all other existing methods. The model of the test-system based on diagnostic signatures was able to diagnose CRC in 95 percent of cases, compared to 79 percent detected by traditional methods. The sensitivity of CRC detection (in patients with Stage II-IV CRC) was 87 percent versus 21 percent. This increase is clearly a significant achievement. The specificity of the method is 97 percent.

The sensitivity of a diagnostic method is its capacity to detect a disease. The higher the sensitivity, the better the results, but sensitivity on its own is not enough to make a diagnosis. The tests must also be correct in cases of another diagnosis, i.e. if there is no cancer, the results should not say that there is cancer.

"The method developed at EIMB RAS has great potential to be used in diagnosing gastrointestinal diseases. We hope that testing systems based on the method will soon appear in clinical laboratories in Russia," says Zhanna Zubtsova, one of the authors of the new method, Ph.D. in Physics and Mathematics, assistant professor at MIPT.

COMPAMED-tradefair.com; Source: Moscow Institute of Physics and Technology

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