NEWS Health News Study Identifies Most Important Genetic Factors in Breast Cancer Risk By Korin Miller Korin Miller Korin Miller is a health and lifestyle journalist who has been published in The Washington Post, Prevention, SELF, Women's Health, The Bump, and Yahoo, among other outlets. Learn about our editorial process Updated on January 25, 2021 Fact checked Verywell Health content is rigorously reviewed by a team of qualified and experienced fact checkers. Fact checkers review articles for factual accuracy, relevance, and timeliness. We rely on the most current and reputable sources, which are cited in the text and listed at the bottom of each article. Content is fact checked after it has been edited and before publication. Learn more. by James Lacy Fact checked by James Lacy LinkedIn James Lacy, MLS, is a fact-checker and researcher. James received a Master of Library Science degree from Dominican University. Learn about our editorial process Share Tweet Email Print seksan Mongkhonkhamsao / Getty Images Key Takeaways A large-scale study has narrowed down important genetic risk factors for breast cancer.While anyone, regardless of gender, can develop breast cancer, there are certain factors that put someone at greater risk of developing the disease, like family history.These findings may help doctors determine what to look out for when determining breast cancer risk through genetic testing. A new, large-scale study has identified the most important genetic factors in a person’s breast cancer risk. The study was conducted by 250 researchers from institutions and universities in more than 25 countries. The study, which was published on January 20 in the New England Journal of Medicine, analyzed data from more than 113,000 women—some who had breast cancer and some without the disease. The researchers specifically looked at 34 genes that are thought to raise a woman’s risk of breast cancer. The risk of developing breast cancer is partially linked with genetics, but figuring out exactly which genes increase the risk is still being explored. Study Supports Genetic Testing for All Breast Cancer Patients After studying the data, the researchers pared down the list of genes that can raise breast cancer risk to nine. Those include: ATMBRCA1BRCA2CHEK2PALB2BARD1RAD51CRAD51DTP53 The importance of each gene varies depending on the type of cancer someone may have. Variations in five genes—ATM, BRCA1, BRCA2, CHEK2, and PALB2—were linked with a higher overall risk of developing breast cancer, while variants in ATM and CHEK2 were more likely to indicate a risk for estrogen receptor-positive breast cancers. How Having a BRCA Mutation Affects Breast Cancer Risk “The results of this study define the genes that are most clinically useful for inclusion on panels for the prediction of breast cancer risk, as well as provide estimates of the risks associated with protein-truncating variants, to guide genetic counseling,” the researchers concluded. What This Means For You Researchers have pared down possible genetic risk factors for breast cancer. If you happen to have one of them, your doctor should be able to recommend any next steps to keep you as healthy as possible. Breast Cancer Risk Breast cancer is the most common cancer for women in the U.S., behind skin cancers, according to the American Cancer Society. The average risk of developing breast cancer for a woman in the U.S. is 13%—or a one in eight chance. While anyone, regardless of gender, can develop breast cancer, there are certain factors that put someone at greater risk of developing the disease, including: Getting olderHaving certain genetic mutationsGetting menstrual periods before age 12 and starting menopause after age 55Having dense breastsA personal history of breast cancer or certain noncancerous breast diseasesA family history of breast or ovarian cancerA previous treatment using radiation therapyHaving previously taken the drug diethylstilbestrol (DES) Impact on Genetic Testing This study “basically confirms what we already know,” Banu Arun, MD, a professor in the Department of Breast Medical Oncology at The University of Texas MD Anderson Cancer Center in Houston, tells Verywell. Doctors already test for these genes when screening patients for breast cancer risk, Arun says. However, she points out, the findings may help doctors home in on how many genes they test for. “I’m hoping this will clarify that maybe there are 50 genes out there that we can test for, but we don’t have to test for all 50,” she says. Genetic Testing for Breast Cancer The study also underscores that certain BRCA gene mutations have a higher risk for developing cancer, Arun says, adding, “this study and others can help give relative risks, so you can determine the significance of someone’s results based on that.” If you do happen to test positive for one of these genes or genetic variants, Arun says you shouldn’t panic. “The ordering physician or genetic counselor will discuss next steps with you,” she says. “There are recommendations and best practices to help.” What Is Genetic Testing for Cancer? 3 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Consortium BCA. Breast cancer risk genes — association analysis in more than 113,000 women. New England Journal of Medicine. doi:10.1056/NEJMoa1913948 American Cancer Society. How common is breast cancer? Centers for Disease Control and Prevention, What are the risk factors for breast cancer? Editorial Process Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit