Pill for breast cancer diagnosis may outperform mammograms

Sunday, May 20, 2018

Print this page Email A Friend!


AS many as one in three women treated for breast cancer undergo unnecessary procedures, but a new method for diagnosing it could do a better job distinguishing between benign and aggressive tumours.

Researchers at the University of Michigan are developing a pill that makes tumours light up when exposed to infrared light, and they have demonstrated that the concept works in mice.

Mammography is an imprecise tool, a recent release said. About a third of breast cancer patients treated with surgery or chemotherapy have tumours that are benign or are so slow-growing that they would never have become life-threatening, according to a study out of Denmark last year.

In other women, dense breast tissue hides the presence of lumps and results in deaths from treatable cancers. All that, and mammograms are notoriously uncomfortable, the release said.

“We overspend US$4 billion per year on the diagnosis and treatment of cancers that women would never die from,” said Greg Thurber, U-M assistant professor of chemical engineering and biomedical engineering, who led the team. “If we go to molecular imaging we can see which tumours need to be treated.”

The move could also catch cancers that would have gone undetected. Thurber's team uses a dye that responds to infrared light to tag a molecule commonly found on tumour cells, in the blood vessels that feed tumours and in inflamed tissue. By providing specific information on the types of molecules on the surface of the tumour cells, physicians can better distinguish a malignant cancer from a benign tumour.

Compared to visible light, infrared light penetrates the body easily — it can get to all depths of the breast without an X-ray's tiny risk of disrupting DNA and seeding a new tumour. Using a dye delivered orally rather than directly into a vein also improves the safety of screening, as a few patients in 10,000 can have severe reactions to intravenous dyes. These small risks turn out to be significant when tens of millions of women are screened every year in the US alone.

But it's not easy to design a pill that can carry the dye to the tumour.

“To get a molecule absorbed into the bloodstream it needs to be small and greasy, but an imaging agent needs to be larger and water-soluble- so you need exact opposite properties,” Thurber said.

Fortunately, they weren't the only people looking for a molecule that could get from the digestive system to a tumour. The pharmaceutical company Merck was working on a new treatment for cancer and related diseases. They got as far as phase II clinical trials in demonstrating its safety but, unfortunately, it wasn't effective.

“It's actually based on a failed drug,” Thurber said. “It binds to the target, but it doesn't do anything, which makes it perfect for imaging.”

The targeting molecule has already been shown to make it through the stomach unscathed and the liver also gives it a pass, so it can travel through the bloodstream. The team attached a molecule to this drug that fluoresces when it is struck with infrared light. Then, they gave the drug to mice that had breast cancer, and they saw the tumours light up.

ADVERTISEMENT




POST A COMMENT

HOUSE RULES

1. We welcome reader comments on the top stories of the day. Some comments may be republished on the website or in the newspaper � email addresses will not be published.

2. Please understand that comments are moderated and it is not always possible to publish all that have been submitted. We will, however, try to publish comments that are representative of all received.

3. We ask that comments are civil and free of libellous or hateful material. Also please stick to the topic under discussion.

4. Please do not write in block capitals since this makes your comment hard to read.

5. Please don't use the comments to advertise. However, our advertising department can be more than accommodating if emailed: advertising@jamaicaobserver.com.

6. If readers wish to report offensive comments, suggest a correction or share a story then please email: community@jamaicaobserver.com.

7. Lastly, read our Terms and Conditions and Privacy Policy



comments powered by Disqus
ADVERTISEMENT

Poll

ADVERTISEMENT
ADVERTISEMENT

Today's Cartoon

Click image to view full size editorial cartoon
ADVERTISEMENT