These images show how the oral pill lit up breast cancer tumors of mice 1, 24 and 48 hours after administration.
Image credit: Thurber Lab
While the number of women affected by breast cancer remains high, rates of the disease have been falling since 1989, which is partly attributed to early detection as a result of increased breast cancer screening.
Screening for breast cancer involves a mammogram, which is an X-ray of the breasts that enables detection of tumors that cannot be felt.
While breast cancer screening leads to early diagnosis for some patients, there are some potential downfalls to the method.
Mammograms can yield false-positive results - where a mammogram appears abnormal but there is no cancer present - because the screening method is unable to distinguish between benign and cancerous tumors.
"Screening can potentially catch the disease early in some patients, but false-positives can lead to unnecessary, aggressive treatments in patients who don't need them," explains study researcher Greg Thurber, PhD, of the University of Michigan. "We don't know how to select the right patients to treat. Our work could help change that."
Dye in pill binds to cancer cells, fluorescing under near-infrared light
Thurber and colleagues have created an oral pill containing a fluorescent imaging agent that, when swallowed, can bind to cancer cells or tumor-specific blood vessels. Once attached, the imaging agent fluoresces under near-infrared light, highlighting only the cancerous tumors.
The researchers tested their pill on mice with breast cancer tumors and found that around 50-60% of the imaging agent was absorbed into the rodents' bloodstream.
Fast facts about breast cancer
- Around 1 in 8 women in the US will be diagnosed with invasive breast cancer in their lifetime
- This year, more than 40,000 American women will die from breast cancer
- There are more than 2.8 million breast cancer survivors in the US.
Furthermore, the agent was found to effectively target and bind to breast cancer cells of the mice, and the fluorescent signal from their tumors was much stronger than that of the surrounding tissue, making them clear to see.
The researchers say this latter finding would benefit women with dense breast tissue, whose mammograms can be difficult to interpret.
The team notes that, normally, near-infrared light would only be able to identify fluorescent tumors that are around 1-2 cm deep. However, Thurber says that because of the elasticity of breast tissue, combining near-infrared light with ultrasound would enable the detection of most cancers.
Next, the researchers hope to develop a pill that is suitable for humans; they plan to formulate the pill so it has the ability to distinguish aggressive tumors from slow-growing, non-invasive breast cancers, such as ductal carcinoma in situ.
While it is likely to be a while before the pill enters human clinical trials, Thurber notes that the dye they used has already been approved for a number of clinical applications in some European countries, which could hasten its approval in the US.
Earlier this month, Medical News Today reported on a study that found a combination of two cancer drugs completely eradicated breast cancer tumors in 11 days.