Scientists are hoping to get closer to developing personalized treatment for breast cancer. Results from the largest study to date of the genomes of breast cancers uncovered five new genes associated with the disease.
Led by Dr. Serena Nik-Zainal of the Wellcome Trust Sanger Institute in England, researchers sequenced 560 breast cancer genomes of patients from the U.S., Europe and Asia. Their conclusion: Breast cancer genomes are highly individual in people.
A closer look at personal cancer genomes
By examining the cancer genome of a person, researchers get a complete historical account of the genetic changes that have occurred during that person's life. From egg to adulthood, the DNA in an individual's cells goes through genetic changes. That’s because DNA is constantly being damaged by things in the environment or simply by wear and tear in the cell.
In addition to the discovery of the five new genes associated with tumors, the researchers identified 13 gene mutation patterns referred to as mutational signatures. These signatures map where biological processes go wrong in cells that become cancerous. Putting all of the data from the genes and mutation patterns together enables scientists to look for hints to the cause of a person’s cancer.
Scientists already know that women who carry the BRCA1 or BRCA2 gene have a higher risk of developing breast and ovarian cancer. Researchers on Dr. Nik-Zainal’s team found that the cancer genome profiles of these women in the study were highly distinctive from each other and from other breast cancers. This discovery could be used to classify patients more accurately for treatment.
Using the genomic data to test drugs in clinical trials is the logical next step for the researchers. "In the future, we'd like to be able to profile individual cancer genomes so that we can identify the treatment most likely to be successful for a woman or man diagnosed with breast cancer,” said Dr. Nik-Zainal. “It is a step closer to personalized health care for cancer."
FAQs about breast cancer
Here are a few common questions and answers about breast cancer.
1. Does inheriting a harmful mutation in the BRCA1 or BRCA2 gene mean you will develop breast cancer?
No, but the risk does go up. Women who inherit a harmful gene mutation are about five times more likely to develop breast cancer than women who don’t. They also are at increased risk for ovarian cancer. These women should talk to their health care providers about genetic counseling.
2. Is there an optimal time to perform a monthly breast self-exam?
Yes. Young women should perform a breast self-exam seven to 10 days after their period starts. This is when breasts tend to be the least tender and lumpy. Women who are in menopause or older should perform a breast self-exam on the same day every month.
3. Does a family history of breast cancer put you at higher risk?
Yes. Having a mother, sister or daughter with breast cancer does raise the risk. But most women who have breast cancer – more than 85 percent – have no family history.
4. How often should I see my doctor for a breast exam or screening, such as a mammogram?
Experts aren’t in total agreement on the answer to this question. See the American Cancer Society’s recommendations here.
Talk to your health care provider for guidance on breast screenings. If you have a family history of cancer, also discuss whether genetic testing is an option for you.
Don’t have a provider? Find a Providence provider here.