Breast cancer screening could become less invasive

A team of Toronto-based scientists is hoping to revolutionize how quickly breast cancer is diagnosed and treated using a technique that evaluates teeny-tiny fluid samples, thereby significantly reducing the invasiveness of conventional methods.

Scientists at the University of Toronto are employing a technology called digital microfluidics -- where minute droplets of fluid are manipulated electrically on the surface of a microchip -- to quantify hormone samples "1,000 times smaller" than those currently analyzed.

Sometimes referred to as "lab-on-a-chip" technology, the fluid samples pass through a device that can fit into the palm of a hand.

Lab director and chemist Aaron Wheeler said the research team was successful in analyzing hormones in blood, serum and breast tissue samples over the two-year study period.

"This is relatively new and hasn't been applied to much yet; certainly not applied to anything like what we've done here," said Wheeler. "It ends up being a perfect format for working with messy clinical samples." The idea is to translate the practice to monitor estrogen levels in fluids extracted from breast tissue using a simple needle.

Higher concentrations of estrogen are found in the breast tissue of women with breast cancer than of healthy women, and is therefore believed to be linked to disease risk.

But most women are not routinely screened for this because conventional procedures are so invasive.

Estrogen levels in breast tissue are currently measured using a 500-milligram biopsy extracted from a piece of breast tissue about the size of a Tootsie Roll. Screened patients must undergo anesthesia and the procedure carries the risk of scarring.

"Up until now, there hasn't been a good way to measure estrogen in the breast, because you needed quite a lot of breast tissue in order to extract (enough) estrogen," said Dr. Robert Casper, an endocrinologist and one of the principal investigators on the project.

"Most women wouldn't volunteer to give up a chunk of their breast for an estrogen measurement."

With this technique, however, Casper said all that's needed is "a drop of fluid" the size of a pinhead.

"I think the clinical implications could be quite significant," he said. "We think we can actually prevent breast cancer, or at least identify people who are at high risk for breast cancer, which would allow us to take steps to reduce their risk."

The technique has yet to be tested using breast-tissue fluids extracted by needle, but Casper said screening for test subjects is currently underway for that study and definite results would be ready within a year.

Wheeler added it would likely take five to 10 years before initial results of the study are translated into the practice -- dependent on funding -- he said the technology could be used "immediately" for infertility treatment and to detect illegal doping in athletes. The research is featured as the cover story in the inaugural edition of Science Translational Medicine, a health-focused journal launched Wednesday.