New blood test could 'transform' cancer treatment: B.C. research

A new study out of the University of British Columbia has found that more personalized cancer treatments can be developed by drawing just a few drops of blood from a patient.

In a news release last week, researchers at BC Cancer and the Vancouver Prostate Centre said they've developed a new blood test that provides "unprecedented" insight into a patient's cancer make-up.

"The first-of-its-kind blood test analyzes the DNA that metastatic cancers shed into the bloodstream, known as circulating tumour DNA or ctDNA," researchers said.

The test then helps to reveal characteristics that are unique to each patient's cancer, which gives physicians new tools to develop more personalized treatment plans.

"With only a few drops of blood, we can uncover critical information about a person's overall disease and how best to manage their cancer," said lead author and UBC professor Dr. Alexander Wyatt in the release.

"This test has the potential to help clinicians choose better tailored treatment options and to more efficiently detect treatment resistance, allowing clinicians to adjust clinical care as needed."

The study analyzed ctDNA samples collected from patients who have metastatic prostate cancer.

"Metastatic cancer — cancer that has spread to other organs in the body — is not often curable, and chemotherapy and newer targeted therapies may not work for all patients," researchers said.

"Biopsies to help determine the best treatments for this type of cancer are rarely performed due to their invasive nature and the high risk of complications."

However, researchers found that whole genome sequencing of ctDNA provides a host of information about the different metastases spread throughout the body.

"Metastatic cancers are complex and our understanding of them has been limited," said Wyatt. "Whereas traditional biopsies only provide a small snapshot of the disease, this new test is able to paint a more complete picture of metastases throughout the body, all from a simple and easy-to-perform blood test."

Researchers added that this information can also be used to help predict which treatments will be effective or ineffective in each patient.

"Every cancer is unique and every patient responds differently to treatment," said Wyatt. "This new generation of ctDNA tests can help clinicians choose the treatment option that is most likely to benefit a patient."

The study also provided new insights into treatment resistance, which researchers said occurs when treatments stop working.

"Drug resistance can develop over time as cancer cells accumulate molecular changes that make them less sensitive to a particular drug or treatment," researchers said.

By collecting multiple ctDNA samples over time, researchers said they were able to learn how metastatic prostate cancer evolves in response to treatment.

"This technology can be applied across other types of cancer to understand how those tumours metastasize and how they eventually evade treatment," said Wyatt.

"It will also help us design the next generation of cancer therapies that more effectively target resistant disease."

Researchers said this minimally-invasive technology is now being deployed across large clinical trials at BC Cancer and the Vancouver Prostate Centre.