The digital microfluidic device designed to extract estrogen from clinical samples. The droplets pictured are coloured with dyes. (Courtesy of Aaron Wheeler)

A "lab-on-a-chip" developed in Toronto measures estrogen in blood and breast tissue, a finding that may someday lead to a faster way to determine a woman's risk of breast cancer.

The palm-sized chip can analyze samples thousands of times smaller than those required for conventional screening methods, meaning a needle prick could draw enough to analyze instead of taking a scar-forming biopsy, possibly under general anesthetic.

The chip is Wednesday's cover story in the debut issue of the journal Science Translational Medicine.

The device is a prototype that the team hopes could be used in doctors' offices within five years, instead of the expensive, time-consuming process of sending samples to a lab.

"You don't need a pathology lab, you don't need a clinical lab," said co-principal investigator Aaron Wheeler, a professor of biomedical engineering at the University of Toronto.

"All you need is a physician, a handheld device, a quick and non-invasive sample and you get a clinically relevant answer."

Estrogen droplets

The chip does not diagnose breast cancer itself, but helps show whether estrogen levels are elevated, which can signal a higher risk for the disease.

In the study, researchers looked at blood, serum and cancerous tissue from two breast cancer patients. Using a new technology called digital microfluidics, they were able to determine the amount of estrogen in the tissue from samples the size of a droplet of rain on windshield.

Instead of moving electrons across tiny wires, minute droplets of fluid containing tissue are manipulated electrically on the microchip surface, drawing out the hormone so it can be measured.

The team said the new method may be useful to:

• Screen populations at high risk of breast cancer or prostate cancer.
• Monitor response to therapies, such as anti-estrogen treatments for estrogen-positive breast cancers.
• Monitor hormone levels in infertility treatments.
• Detect illegal doping in athletes.

Breast estrogen is not routinely measured because conventional procedures are costly and painful.

"We know that high levels of [estrogen] can be indicative of breast cancer, so this would be another way of monitoring those women to see if there's an upswing or surge in estrogen," said Dr. Christine Williams, director of research for the Canadian Cancer Society's research institute, which is funding the research.

"They could then go on a preventive or early treatment regimen."

While the research illustrates how many technologies can be integrated on to a lab-in-a-chip device, bringing down the cost given the materials will be a challenge, said Prof. Jon Cooper, an expert on such technologies at the University of Glasgow who was not involved in the study.

With files from The Canadian Press