Researchers at the University of Michigan are shining some light on breast cancer, the second most common cancer in American women. This year, it is expected that more than 246,000 women will be diagnosed with a form of the disease.

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 because the screening method is unable to distinguish between benign and cancerous tumors. These false positives often lead to unnecessary, aggressive treatments in patients who don't need them.

Now, a team of scientists have created a pill containing a fluorescent imaging agent that, when swallowed, can bind to cancer cells or tumor-specific blood vessels. Under near-infrared lamps, anycancerous tumors will, for all intents and purposes, light up.

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.

The team notes that, normally, near-infrared light would only be able to identify fluorescent tumors that are around 1 to 2 centimeters deep. But because of the elasticity of breast tissue, combining near-infrared light with ultrasound should 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.

While it is likely to be a while before the pill enters human clinical trials, 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.