Factors Not Linked to an Increased Breast Cancer Risk
Many factors have been studied to see whether or not they increase the risk of breast cancer.
Some of these factors have been shown to be unrelated to breast cancer and are not linked to an increased risk. Some may even be linked to a decreased risk of breast cancer, although these findings are not conclusive.
A full list of factors not related to breast cancer risk is too long to present here. Some, however, deserve mention because they’ve been studied more than most or they’ve gotten a lot of media attention.
Our Breast Cancer Risk Factors Table compares these and other factors by level of risk and strength of evidence.
The factors below are listed alphabetically.
Where do the data come from?
The data in this section come from 2 main types of research studies:
The goal of these studies is to give information that helps support or disprove an idea about a possible link between an exposure (such as alcohol use) and an outcome (such as breast cancer) in people.
Although they have the same goal, observational studies and randomized controlled trials differ in:
- The way they are conducted
- The strength of the conclusions they reach
Learn more about different types of research studies.
Animal studies add to our understanding of how and why some factors may be linked to cancer in people.
However, there are many differences between animals and people, so it makes it hard to translate findings directly from one to the other.
Animal studies are also designed differently. They often look at exposures in larger doses and for shorter periods of time than are suitable for people.
While animal studies can lay the groundwork for research in people, we need human studies to draw conclusions for people.
All the data presented within this section of the website come from studies of people.
Finding information on risk factors
Susan G. Komen® has up-to-date information on many established, probable and possible risk factors for breast cancer. We also have information on many factors shown not to be related to breast cancer.
Some scientific, reputable organizations conduct research and/or prepare detailed evidence-based summary reports on certain factors shown to have a link (or no link) to breast cancer and other types of cancer. These organizations include:
- International Agency for Research on Cancer (IARC)
- Centers for Disease Control and Prevention (CDC)
- National Toxicology Program (NTP)
- U.S. Food and Drug Administration (FDA)
IARC is a part of the World Health Organization. The CDC, NTP and FDA are all part of the U.S. Department of Health and Human Services.
To learn more about the role of the environment in breast cancer, Susan G. Komen® sponsored a study from the National Academies of Sciences, Engineering, and Medicine (formerly the Institute of Medicine), “Breast Cancer and the Environment, a Life Course Approach.”