Doctors should resample patient tissue should cancer spread, rather than relying on the initial biopsy, according to research focused on estrogen-positive breast cancer.
[O]ur results suggest tumours switch different genes on and off as they progress, and can fundamentally change their ‘appearance’. Therefore if a tumour becomes more aggressive, and spreads around the body, we would advise always taking a second biopsy. The cancer might have changed significantly in this time, and would respond to different treatments. Although taking a second biopsy when a patient’s cancer relapses is becoming much more common, it’s still not happening all the time.
This research showed that “cancer cells are much more reliant on Yin Yang1 than normal cells and that it may drive breast cancer growth.” Yin Yang1 is a type of molecule (a transcription factor) which helps turn genes in a cell on-or-off; each cell contains about 25,000 genes.
Aggressive cancer that has spread may have a different epigenetic profile due to Yin Yang1 activity, affecting how the cancer responds to treatment.
It was a small study – 34 patients patients whose cancer had not spread around the body and 13 patients with more advanced breast cancer – but it revealed that Yin Yang1 turned on SLC9A3R1, “might help cancer cells grow and evade treatment.”
Next steps are to analyze more patients and investigate triple negative breast cancer.
The international research team included the European Institute of Oncology in Milan, the University of Liverpool and Case Western Reserve University in Cleveland.