Breast cancer normally develops either in the ducts – the tiny tubes that carry milk to the nipple – or the lobules that are the milk-producing glands. For a malignant breast tumour to grow it needs nourishment that is provided by new blood formation in a process known as angiogenesis. These changes to both the anatomical structure and physiological function of the breast provide an ideal opportunity to use medical imaging for early diagnosis of cancer. One of the challenges faced by radiologists is that mammography – an X-ray of the breast – only reveals the underlying anatomy and so cannot readily distinguish between benign and malignant tumours.
Greg Thurber (above right) is a young assistant professor of chemical engineering at the University of Michigan who has just been awarded a prestigious Career Development Award by the National Science Foundation. His research group, which has a growing list of publications in important journals, focuses on the development of imaging molecules to facilitate screening, diagnosis, intra-operative imaging and monitoring of treatment. Ten days ago, the American Chemical Society, the world’s largest scientific society with more than 150,000 members, held its annual meeting in San Diego.
Thurber presented his group’s latest findings at the meeting and his paper, entitled “Disease screening pill for breast cancer”, was featured in a press release published on YouTube. He explained how they created a pill that can be taken orally and contains an imaging agent that fluoresces when exposed to near-infrared light. After being swallowed, the pill passes through the gastro-intestinal tract into the blood stream and the imaging agent then selectively binds to cancer cells or the blood vessels feeding the tumour.
As seen in the image at left (© Thurber Lab), the pill was successfully tested in mice where the fluorescent signal from the tumour was far greater than the signal from the surrounding tissues. One of the potential limitations of the system is that near-infrared light can only penetrate through 1 to 2 centimetres of tissue – and some breast cancers can be considerably deeper than this – although Thurber was optimistic his technique can be paired with ultrasound to overcome the problem. He also acknowledged the challenge of scaling the pill from small animals to humans.
Thurber concluded: “The high image contrast should bode well for women with dense breast tissue whose mammograms are difficult to read. We are also designing the agent to specifically seek out aggressive tumours and distinguish them from slow-growing cancers, such as ductal carcinoma in situ.”
Finding beast cancer early is the name of the game, but this is easier said than done!
“We are also designing the agent to specifically seek out aggressive tumours, and distinguish them from slow-growing cancers, such as ductal carcinoma in situ.”
This will be a giant leat forward! While all this is going on, finding breast cancers using a combo of ultrasound and a 3D X-ray machine is what will really save so many more women’s lives.
Ian Grant-Whyte, MD
The pill approach seems to be an new trial to improve the “historical” Thermographie – a method of good sensitivity in detecting suspect breast lesions, but with an insufficient specificity.
A more modern approach was the Color-Doppler 2-ore 3 D sonographic imaging: This method could`t improve sensitivity in detecting lesions, but was able to reduce false positive results of conventional structural B-mode imaging. So we are looking forward to see true progress.
Of “mice and men”. In the Netherlands, organised from Utrecht we (Amsterdam) cooperated in a phase 1 trial. Philips made a real human fluorescence scanner for human use (with cups, prone position etc).
A picture can be found: Biomed. Opt. 17(7), 076022 (Jul 17, 2012). doi:10.1117/1.JBO.17.7.076022.
It appeared that humans reacted to the dye different than mice. Project was stopped after one year. We never included a patient because of the disappointing results and the machine was removed.
Hopefully these results will be useful for others.