Scientists have developed a method to detect early signs of lung cancer by examining cheek cells in humans.
The technique, known as partial wave spectroscopic (PWS) microscopy, can detect cell features as small as 20 nanometers, which would appear as normal when using a standard microscope.
The PWS-based test makes use of the “field effect,” a biological phenomenon in which cells located some distance from the malignant or pre-malignant tumour undergo changes to their molecular structure.
After testing the technology in a small-scale trial, American researchers focussed their efforts on a group of smokers because smoking is a major risk factor for lung cancer. Of the 135 patients studied, 63 had lung cancer, 37 had chronic obstructive pulmonary disease (COPD) and 22 were non-smokers.
The researchers swabbed the inside of patients’ mouths, and then the cheek cells were applied to a slide, fixed in ethanol and optically scanned using PWS to measure the “disorder strength” of cells. It has been found previously that the increase in the disorder strength of cells is one of the earliest events in the cancer process (carcinogenesis).
The disorder strength of cells in lung cancer patients was more than 50 per cent greater than in smokers without cancer. The test was equally sensitive to cancers of all stages, including early curable cancers.