Scientists seek breast cancer biomarkers in a drop of blood

Breast cancer diagnosis in the form of mammography can be costly and uncomfortable, and can miss early cancers. Needle and surgical biopsies are invasive, ultrasound can lead to false positives, and single-biomarker tests, such as carcinoembryonic antigen (CEA), can be imprecise. So, that leaves a big "area of unmet need" as companies often say. The ideal diagnostic would be a simple drop of blood in a handheld test looking at a range of biomarkers, and researchers at McGill University in Canada have announced this as their goal.

The number of proteins they can measure simultaneously limits existing assay technologies. According to David Juncker, the research team's principal investigator, "no reliable set of biomarkers has been found [for breast cancer], and no such test is available today. Our goal is to find a way around this."

So, the team set to work. They analyzed existing protein target analysis technologies and built on these to create a microfluidics-based microarray designed to test larger numbers of proteins and minimize false positives and negatives. They used this to screen for 32 proteins in healthy volunteers and women with estrogen receptor-positive breast cancer, and found 6 proteins that could differentiate between the patients and healthy controls.

"While this study needs to be repeated with additional markers and a greater diversity of patients and cancer subsets before such a test can be applied to clinical diagnosis, these results nonetheless underscore the exciting potential of this new technology," Juncker said.

With up to one in 8 women developing breast cancer in her lifetime, and early diagnosis and treatment having a close link with better outcomes, a simple blood spot test could help physicians diagnose, treat and support women, and even reduce dependence on mammography with its attendant radiation exposure risks for both patients and healthcare professionals.

It's still early, and the researchers know that these studies need to be repeated in larger groups and in more cancer subtypes, but they are keeping their goal in sight and are currently moving toward a handheld test with improved sensitivity that could allow detection in earlier stage cancers.

- read the press release
- see the abstract