Cancer Research UK scientists have now discovered why some breast cancers are resistant to the commonly used drug tamoxifen. This drug is given to women after they have been diagnosed with breast cancer to help prevent the disease from coming back, but some patients can develop resistance to the treatment meaning that their cancer is more likely to return.
The health charity scientists have discovered that when a gene called FGFR1 is over stimulated it can cause breast cancer cells to no longer grow rapidly and spread, making tamoxifen and other hormone treatments less effective.
Scientists were able to switch off FGFR1 in cancer cells by adding a drug that blocks its functions. Once the FGFR1 is switched off, hormone treatments were able to perform far more effectively in destroying cancer cells.
Cancer Research UK funded clinician scientist Dr Nick Turner, said –
We have known for some time that breast cancer patients with too much of the FGFR1 gene in their cancer are more likely to have a poor prognosis, but we did not know if FGFR1 was behind this. Understanding how this gene can cause tamoxifen resistance reveals a new drug target for treating breast cancers in patients who would otherwise have a poor outcome. There are a number of drugs in development that stop FGFR1 working, and clinical studies are investigating whether these drugs work against cancers with too many copies of this gene.
The next step is to set up a clinical trial to see whether a drug that blocks the action of this gene can counteract hormone therapy resistance in breast cancer patients. If these trials confirm our lab work we could be on the verge of a potentially exciting new treatment for breast cancer.
With breast cancer being the most common cancer in the UK, these findings are fantastic news in helping to personalise each diagnosis to try to ensure that once breast cancer has been treated, that it doesn’t unnecessarily return.
