Researchers use non-invasive ‘diagnostic pill’ to detect breast cancer in mice.
Cancer therapy has been rapidly advancing toward molecular characterization, however, screening technology such as mammograms can be painful and generally rely on anatomical differences that have several limitations. These include the lack of molecular information to identify aggressive tumors versus those that pose no mortality risk and the lack of contrast in dense breast tissue that carries increased risk, particularly prevalent in younger women. These limitations have led to an estimated $4 billion being overspent on false-positives and over diagnosis. Now, a study from researchers at the University of Michigan develops a pill which makes tumors light up when exposed to infrared light in mice. The team state that their new pill could also catch cancers that would have previously gone undetected. The opensource study is published in the journal Molecular Pharmaceutics.
Previous studies show that mammograms are imprecise; about a third of breast cancer patients treated with surgery or chemotherapy that have tumors which are benign or would never have become life-threatening. In women, dense breast tissue hides the presence of lumps and results in deaths from treatable cancers. All that, and mammograms are notoriously uncomfortable, with $4 billion per year spent on the diagnosis and treatment of cancers that women would never die from. Thus molecular imaging is highly desirable in this area as it can provide precise spatial information on disease-associated biomarkers, something neither blood tests nor anatomical imaging can achieve. However, the high cost and risks of ionizing radiation for several molecular imaging modalities have prevented a feasible and scalable approach for screening. The current study develops a disease screening approach for breast cancer using oral administration of a molecular imaging agent.
The current study demonstrates that negatively charged sulfate groups, commonly used to improve solubility of near-infrared fluorophores, enable sufficient oral absorption and targeting of fluorescent molecular imaging agents for completely noninvasive detection of diseased tissue such as breast cancer. These functional groups improve the pharmacokinetic properties of affinity ligands to achieve targeting efficiencies compatible with clinical imaging devices using safe, non-ionizing radiation (near-infrared light).
The team state that together, the aforementioned enables development of a ‘disease screening pill’ capable of oral absorption and systemic availability, target binding, background clearance, and imaging at clinically relevant depths for breast cancer screening. They go on to add that, to their knowledge, this is the first demonstration of a disease screening approach using oral administration of a molecular imaging agent, and these mechanisms should be applicable to additional agents and disease targets for developing a series of molecular imaging agents for noninvasive screening.
The team surmise they have developed a cheap diagnostic pill which binds to breast cancer tumors in mice, and fluoresce when it is struck with infrared light to identify cancerous breast tissue; and could distinguish aggressive tumors from benign, preventing unnecessary breast cancer treatments. For the future, the researchers state that this approach should be adaptable to other molecular targets and diseases for use as a new class of screening agents.
Source: University of Michigan