A rapid technique for analysing biopsy samples could allow surgical teams to determine whether they have removed all traces of cancerous tissue while their patient is still on the operating table, according to the technique’s developers at the US Department of Energy’s Oak Ridge National Laboratory (ORNL). The technique is claimed to be able to return a conclusive result in ten minutes, rather than around 30 minutes as is typical with current tests; moreover, it does not require sample preparation or outside labs.
Cancer tests typically depend on being able to identify proteins in a sample that are characteristic of the type of tumour under study; this is known as immunohistochemistry (IHC). The ONRL team combined this technique with another which the instiution has previously developed, an automated droplet-based liquid microjunction surface sampling probe, which allows samples collected during surgey to be subjected to high-performance liquid chromatography to separate out the various molecules so that they can be identified by mass spectroscopy. Other technologies are being developed for rapid cancer diagnosis, but the ORNL team claims that these can only detect small molecules, whereas theirs can identify the larger molecules like peptides and proteins that are necessary to provide accurate diagnoses.
Team leader Vilmos Ketsesz said that the technique has been used sucessfully to identify drug residues and other biological molecules in thin tissue samples and even dried blood, and is capable of spatial resolution, ie determining whereabouts within the sample the molecules were found. “On the basis of the results and the relative simplicity, rapidity and specificity of our method, there is great potential for our technology to assist surgeons in the detection of cancer from tissue biopsy samples,’ he said in a paper in the journal Analytical and Bioanalytical Chemistry. Kertesz hopes to halve the time the test takes in an operating theatre. “Instead of having to cut and mount tissue and wait for a trained pathologist to review the sample under a microscope, a technician might soon perform an equally conclusive test in the operating environment.’ he said.