Researchers have developed a new method of using light to detect if cancer cells are responding to treatment.
The team from Vanderbilt University developed a test which allows them to detect over-expression of human epidermal growth factor receptor 2 (HER2), which is displayed at higher than normal levels in cancer cells.
HER2 is associated with one of the most aggressive forms of breast cancer and in around 30 per cent of cases does not respond to life prolonging drugs. HER2 positive tumours grow more quickly than other types of breast cancer.
Some cancer cells use a different metabolic pathway to normal cells, which the scientists visualised using frequencies of light which caused two different metabolic molecules to fluoresce.
By calculating the difference in light between these two molecules they created an optical redox ratio. Cells with over-expression of HER2 had a higher ratio and in some, but not all cases, this ratio reduced when HER2-blocking drugs were delivered.
However, the decrease was not seen in all cancer cells resistant to the drug and the team believe it could potentially lead to a real-time optical test for if the cancer is responding to drugs.