A new study by researchers at RCSI University of Medicine and Health Sciences and the Beaumont RCSI Cancer Centre has identified a gene called RET as a crucial factor in the spread of breast cancer to the brain.

The research, published in Journal of the National Cancer Institute, provides valuable insights into how breast cancer cells move and grow in the brain, pointing to potential new treatment avenues for patients. 

Breast cancer brain metastases, where cancer spreads from the breast to form secondary tumours in the brain, pose significant treatment challenges and are often associated with poor prognosis. The research, led by senior authors Professor Leonie Young and Dr Damir Varešlija, with Dr Petra Jagušt as first author, highlights the role of the RET gene in worsening outcomes for hormone receptor-positive breast cancers. 

“By pinpointing RET's role in promoting brain metastases, our research offers hope for developing strategies that can interrupt this process, potentially leading to better outcomes for patients suffering from this devastating complication of breast cancer,” said Professor Young, Scientific Director of the Beaumont RCSI Cancer Centre. 

The research team collaborated with clinicians at the Beaumont RCSI Cancer Centre and compared RET activity between cells from primary breast tumours and secondary brain metastatic tumours. They found that the RET gene, working together with another growth-related gene called EGFR, triggers processes that enable cancer cells to stick together and spread, facilitating the cancer’s aggressive movement to the brain. 

“Our findings show that when the RET gene is overactive in breast cancer cells, it helps them navigate and colonise the brain environment,” explained Dr Petra Jagušt. “Therefore, targeting RET could lead to new treatments for patients with breast cancer that has spread to the brain, who currently have limited treatment options.” 

The research was supported by funding from Breast Cancer Now, Breast Cancer Ireland, and Science Foundation Ireland.