Stem cells have the ability to develop into many different types of cells. One healthy stem cell can grow and develop into a group of liver cells or blood cells or nerve cells -- just about any specialized cell in the body. Genetic mistakes can create abnormal stem cells. An abnormal stem cell can develop into a group of abnormal cells, such as breast cancer cells, which can then grow and spread.
A study found that HER2-positive breast cancers seem to have a large number of abnormal, cancerous stem cells. These cancerous stem cells appear to make HER2-positive breast cancers grow and spread. The researchers found a much lower number of cancerous stem cells in HER2-negative breast cancers.
HER2-positive breast cancers have extra HER2 genes and make too many HER2 protein receptors. About 1 out of every 4 breast cancers is HER2-positive. HER2-positive breast cancers tend to be more aggressive than HER2-negative breast cancers. This study suggests that cancerous stem cells may be the reason why HER2-positive breast cancers are more aggressive. The researchers think that the extra HER2 genes and proteins help abnormal stem cells develop.
Herceptin (chemical name: trastuzumab) is a targeted therapy medicine used to treat HER2-positive breast cancers. This study found that Herceptin lowered the number of abnormal stem cells in HER2-positive breast cancers by 80%. The researchers think that Herceptin works by targeting abnormal stem cells.
While this research won't have an immediate effect on treatment, it helps doctors better understand how breast cancers develop and spread and may lead to even better ways to treat breast cancer. Stay tuned to Breastcancer.org for the latest news on research to prevent, diagnose, and treat breast cancer.