Posts Tagged ‘breast cancer’

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 tumors.

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

Mammography is an imprecise tool. About a third of breast cancer patients treated with surgery or chemotherapy have tumors that are benign or 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.

“We overspend $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 tumors 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 tumor cells, in the blood vessels that feed tumors and in inflamed tissue. By providing specific information on the types of molecules on the surface of the tumor cells, physicians can better distinguish a malignant cancer from a benign tumor.

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 tumor. 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 U.S. alone.

But it’s not easy to design a pill that can carry the dye to the tumor.

“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 tumor. The pharmaceutical company Merck was working on a new treatment for cancer and related diseases. They got as far as phase II clinical trials 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 that fluoresces when it is struck with infrared light to this drug. Then, they gave the drug to mice that had breast cancer, and they saw the tumors light up.

The research is described in a study in the journal Molecular Pharmaceutics, titled, “Oral administration and detection of a near-infrared molecular imaging agent in an orthotopic mouse model for breast cancer screening.”

This work was done in collaboration with David Smith, the John G. Wagner Collegiate Professor of Pharmaceutical Sciences at the U-M College of Pharmacy. It was supported by the Foundation for Studying and Combating Cancer and the National Institutes of Health.
Bhatnagar, S., Verma, K. D., Hu, Y., Khera, E., Priluck, A., Smith, D., & Thurber, G. M. (2018). Oral Administration and Detection of a Near-Infrared Molecular Imaging Agent in an Orthotopic Mouse Model for Breast Cancer Screening. Molecular Pharmaceutics. doi:10.1021/acs.molpharmaceut.7b00994

Advertisements

Researchers at the Karolinska Institute, Sweden, say guidelines that advise people to stay out of the sun unless wearing sunscreen may be harmful, particularly in northern countries which have long, cold winters.

Exposure to ultraviolet radiation from sunlight is often cited as a cause of skin melanoma (malignant tumour of melanocytes) and avoiding overexposure to the sun to prevent all types of skin cancer is recommended by health authorities.

But the new study, which followed nearly 30000 women over 20 years, suggests that women who stay out of the sun are at increased risk of melanomas and are twice as likely to die from any cause, including cancer.

It is thought that a lack of vitamin D may be to blame. Vitamin D is created in the body through exposure to sunshine and a deficiency is known to increase the risk of diabetes, TB, multiple sclerosis and rickets.

Previous studies showed that vitamin D can increase survival rates for women with breast cancer while deficiencies can signal prostate cancer in men.

The study looked at 29518 Swedish women who were recruited from 1990 to 1992 and asked to monitor their sunbathing habits.

After 20 years there had been 2545 deaths and it was found that women who never sunbathed were twice as likely to have died from any cause.

Women who sunbathed in the mild Swedish summer were also 10% less likely to die from skin cancer, although those who sunbathed abroad in sunnier countries were twice as likely to die from melanoma.

Yinka Ebo, senior health information officer at Cancer Research UK, said striking a balance was important.

“The reasons behind higher death rates in women with lower sun exposure are unexplained . overexposure to UV radiation from the sun or sunbeds is the main cause of skin cancer.”

http://www.timeslive.co.za/thetimes/2014/05/09/avoiding-sunshine-could-kill-you-study-finds

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.