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May 12, 2008

Accurate biochips for comprehensive disease screening


Biochips contain grids of small wells or "dots," each of which contains a protein, antibody or nucleic acid that can bind to a target antigen or DNA sequence.

New biochips can detect cancers and other diseases accurately before symptoms develop.

Why does this matter ? Early detection can have a large impact on survival rates. Breast cancer detected at stage 0 has a 100% survival rate after 5 years. Those who are detected at stage 4 have a 20% survival rate after 5 years. So if everyone had good and accurate and regular disease screening then no one would die of breast cancer even if treatments do not improve. We can already save everyone who has stage 0 breast cancer. This would save 502,000 lives worldwide every year.

Lung cancer five year survival rates
Stage 0 70-80%
Stage I 50%
Stage II 30%
Stage III 5-15%
Stage IV <2%

Detecting everyone at Stage 0 instead of later stages would reduce 1.3 million deaths per year from lung cancer by nearly 1 million people.

Stomach cancer has similar survival statistics as lung cancer

For liver cancer it drops from 30-60% for early detection down to less than 5%

The 2-D fractionation process creates 960 separate protein fractions, which are then arranged in a single biochip containing 96-well grids. Eprogen scientists then probe the microarrays with known serum or plasma "auto-antibodies" produced by the immune systems of cancer patients. By using cancer patients' own auto-antibodies as a diagnostic tool, doctors could potentially tailor treatments based on their personal autoantibody profile

Though the analysis of a sample on a biochip can take 30 minutes, scientists can have much more confidence in the accuracy of the diagnosis, according to Schabacker. "Biochips give us the ability to run a test that allows your doctor to figure out exactly what you're suffering from during the time that you're in his or her office," he said. By adding just a few more drops to the chip's array, Schabacker claimed, lab technicians could test for a whole slate of biotoxins and especially virulent diseases from the plague to smallpox to anthrax. Other infections, such as those caused by Multidrug-Resistant Tuberculosis (MDR-TB) and the often deadly Methicillin-resistant Staphylococcus aureus (MRSA), can be quickly diagnosed with biochips like Akonni's TruArray assay, according to Daitch.

"The unique advantage offered by the TruArray platform lies in the fact that we can screen a single sample for multiple viral and bacterial infections at the same time," said Charles Daitch, Akonni's president and CEO. "Soon, doctors will no longer need to order as many expensive and time-consuming tests, and can instead obtain accurate diagnoses that will enable them to quickly provide their patients with targeted treatment strategies."



Computer algorithms decode the dot pattern produced by the biochip, calculate the statistical likelihood of each possible infection and provide this information to the doctor.


FURTHER READING
Cancer deaths in the USA dropped to 553,888 in 2004, down from 556,902 in 2003 and 557,271 in 2002, the Cancer Society found.

In 2005, 7.6 million people died of cancer worldwide according to the World Health Organization.

Cancer is a generic term for a group of more than 100 diseases that can affect any part of the body. Other terms used are malignant tumours and neoplasms.

40% of cancer can be prevented (by a healthy diet, physical activity and not using tobacco).

One-fifth of cancers worldwide are due to chronic infections, mainly from hepatitis B viruses HBV (causing liver), human papilloma viruses HPV (causing cervix), Helicobacter pylori (causing stomach), schistosomes (causing bladder), the liver fluke (bile duct) and human immunodeficiency virus HIV (Kaposi sarcoma and lymphomas).

lung (1.3 million deaths/year);
Stomach (almost 1 million deaths/year);
Liver (662,000 deaths/year);
Colon (655,000 deaths/year) and
Breast (502,000 deaths/year)

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