Early detection

A NorthwesternUniversitybiomedical engineer has developed an optical instrument that could be used for the early detection of colon cancer.

To conduct further studies on the instrument, Vadim Backman, professor of biomedical engineering at Northwestern’s McCormick School of Engineering and Applied Science, has received a $7.5 million grant over five years from the National Cancer Institute (NCI).

Colon cancer is the second-leading cause of cancer deaths in the United States; more than 50,000 die each year of the disease. Colon cancer, however, can be easily treated if detected early. But no existing population-wide screening test can accurately predict the presence of the disease with adequate sensitivity.

Prof Backman believes the technology he has developed could lead to the first such test. A major part of the NCI grant is to validate the technology and prepare it for commercialisation.

In the future, it is possible that the simple test would be conducted by a physician during an annual exam. Only patients with abnormal results would go on to have the more invasive and expensive colonoscopy.

‘Our hope is that similar to how the routine pap smear drastically reduced deaths from cervical cancer, this new technology could do the same when it comes to colon cancer,’ said Prof Backman.

His optical technique takes advantage of certain light-scattering effects of tissue and is minimally invasive. The method can detect abnormal changes in cells lining the colon long before those changes can be seen under a microscope and even before polyps form.

The technique involves inserting a simple fibre-optic probe roughly the size of a pen into the rectum. Light shines on the tissue at the base of the colon, scatters and some of that light bounces back to sensors in the probe. A computer analyses the pattern of light scattering, looking for a ‘fingerprint’ of carcinogenesis in the nanoarchitecture of the cells.

The method combines two complementary technologies developed by Prof Backman and colleagues in his lab: four-dimensional elastic light-scattering fingerprinting and low-coherence enhanced backscattering spectroscopy.