New hope in the face of triple-negative breast cancer

A drug already used in the fight against other types of breast cancer could be used against triple-negative breast cancer, a particularly aggressive subtype that is likely to recur, shows work carried out at the McGill University Health Centre and published in Molecular Cancer.Triple-negative breast cancer affects approximately 12% of women who are diagnosed with breast cancer, and especially those under the age of 50. However, there is a lack of targeted therapies to attack it.Triple-negative breast cancer is therefore mainly treated with chemotherapy, surgery, radiotherapy and immunotherapy, but recurrence and mortality rates remain high. Additionally, immunotherapy is only appropriate if the patient has a certain genetic mutation.“Unfortunately, there is often a higher percentage of young women and women of colour who are diagnosed with this type of cancer,” explained one study author, Sophie Poulet, who was a doctoral student at the Cancer Research Program at McGill at the time of the study, led by Dr. Jean-Jacques Lebrun.Revolutionized careResearchers used CRISPR technology to identify genes that predict the effectiveness of palbociclib, a widely used CDK4/6 inhibitor. CDK4/6 inhibitors have revolutionized care for a more common type of cancer, hormone receptor-positive advanced breast cancer, by slowing or even stopping the growth of cancer cells.CDK4/6 inhibitors are currently not offered to people with triple-negative breast cancer because they are not considered effective in this subtype of cancer.However, the work demonstrated that palbociclib could be effective in patients whose TGF(beta)3 gene is overexpressed, and suggests treatment could include administering a drug that accentuates the expression of this gene to obtain a synergistic therapeutic effect with palbociclib.“We used a library that allowed us to test the 20,000 human genes in cells individually,” said Poulet. "We turned them off one by one. Then we looked at which cell was more sensitive or more resistant to drugs once the gene was turned off. And that allowed us to obtain a list of genes responsible for changing or regulating drug sensitivity in cells.”These results could make it possible to personalize the treatment of patients with triple-negative breast cancer or other solid tumours by identifying those who carry genes associated with the effectiveness of CDK4/6 inhibitors.Palbociclib is also easier to administer than other treatments, since it comes in tablet form.The conclusions of this study come from lab experiments, and the authors noted that further preclinical work will be needed before palbociclib can be considered for women with triple-negative breast cancer.Breast cancer accounts for a quarter of all cancer diagnoses in women.

New hope in the face of triple-negative breast cancer

Register for free access or login.

Related Topics