Breast Cancer Stem Cell Research
Breast cancer stem cells were discovered in 2003 by scientists at the U-M Comprehensive Cancer CenterIn the fight against breast cancer, there is good news and bad news. The good news is that, since 1990, there has been a steady decline in the death rate from breast cancer. Earlier detection and better treatments are bringing hope to people with both early and advanced disease.
The bad news is that more than 40,000 people die from breast cancer every year in the United States alone. It is still the second-leading cause of deaths from cancer in women. The survival rate for those with advanced, metastatic breast cancer has not changed significantly for decades. In spite of more effective therapies, many patients still experience recurrences of breast cancer after treatment.
We believe that conventional therapies for advanced breast cancer are limited because they target the wrong cells. These therapies were designed to shrink cancers by killing all the cells in a tumor. We believe therapies could be more effective, and cause fewer side effects, if they were aimed specifically at a small group of cells within the tumor called cancer stem cells.
Breast cancer stem cells - the first to be identified in a solid tumor - were discovered in 2003 by scientists at the U-M Comprehensive Cancer Center. U-M scientists found that just a few cancer stem cells are responsible for the growth and spread of breast cancer. Unless the cancer stem cells are destroyed, the tumor is likely to come back and spread malignant cells to other parts of the body, a process called metastasis.
Because cancer stem cells are resistant to traditional chemotherapy and radiation, we need new treatments that can be targeted directly at these deadly cells. U-M Cancer Center scientists are studying breast cancer stem cells to learn more about them and to determine the type of therapy most likely to destroy the cells. The world's first clinical study of a treatment targeted at stem cells in breast cancer was conducted at the U-M Cancer Center and other clinical studies are currently in development.
How do scientists identify breast cancer stem cells?All cells have a unique pattern of proteins, like a fingerprint, on their surface membranes. All breast cancer stem cells have a surface protein marker called CD44, along with very low levels or no levels of two markers called CD24 and lin. Using specialized equipment and techniques, scientists can separate cells with this combination of protein markers from millions of other cells in a tumor sample. U-M scientists also have identified a protein called ALDH, which is produced by cancer stem cells and can be detected in biopsies of patient tumors. Both genetic and non-genetic factors -- including age, radiation exposure, menstrual history and number of pregnancies -- are involved in the development of breast cancer.