• Most U.S. women know physical activity reduces breast cancer risk, but only one-quarter meet recommended levels.
• A majority know alcohol raises cancer risk, but two-thirds consume alcohol to some extent.

Most U.S. women are aware of modifiable risk factors for breast cancer but far fewer incorporate that understanding into everyday actions that could reduce their chances of developing the disease, according to survey results.

“There definitely is a gap between the level of knowledge and the level of action,” Alpa V. Patel, PhD, senior vice president of population science at American Cancer Society, told Healio.

One in eight women in the United States will develop breast cancer in their lifetime.

Family history, age, sex, race, ethnicity, breast tissue density and genetic factors all affect a person’s risk. However, approximately 30% of cases can be attributed to modifiable risk factors, such as physical inactivity, excess body weight and alcohol consumption.

The ongoing Cancer Prevention Study-3 (CPS-3) — led by the cancer society — is prospectively evaluating the genetic, environmental and lifestyle factors that may cause or prevent cancer.

“We have followed this study population for more than a decade, and levels of certain behavior patterns that help reduce risk for breast cancer have been lower than what we want to see,” Patel said. “We wanted to understand whether people don’t know certain behaviors lower risk for breast cancer, or if they are aware but they either are not able or choose not to engage in those activities.”

Researchers administered a survey to 33,000 women participating in CPS-3 to assess their awareness of modifiable breast cancer risk factors, and the extent to which they are meeting American Cancer Society recommendations for prevention and risk reduction.

Results showed:

• 99% of women are aware that family history of cancer places them at higher risk;
• 91% know physical inactivity increases cancer risk; however, only 27% meet recommended weekly activity levels;
• 85% know alcohol consumption increases cancer risk; however, 69% indicated they drink alcohol to at least some extent; and
• 55% know breastfeeding can help reduce cancer risk.

The fact that all survey respondents have been engaged in the cancer society’s long-term research study likely explains why their awareness of cancer risk factors is higher than what would be expected in the general population, Patel said.

Healthcare professionals play an important role in the effort to ensure more U.S. women develop that same knowledge and increase the proportion who act on it, Patel said.

“Many women think that, because no one in their family has had breast cancer, they don’t need to worry about it,” Patel said. “But 85% of breast cancers are diagnosed in women who have no family history. The clinical community is essential as a trusted source of information about how factors such as exercise, nutrition, body weight, alcohol and tobacco affect cancer risk.”

The greatest opportunity to close the gap between awareness and action may be through promoting physical activity, Patel said.

“Physical activity is a wonder drug. Beyond cancer prevention, it is beneficial for heart health, diabetes, mental health, and so many other aspects of quality and quantity of life,” she said. “I have friends who say, ‘I know your research shows I need to be exercising, but I’m not doing anything and it feels overwhelming.’ Simple messaging from clinicians can emphasize that no one needs to be perfect, and that something is better than nothing. They can help patients pick one action that feels achievable and hopefully they can build from there. Even small changes in your everyday life will offer benefits.”

A similar approach toward alcohol consumption also could pay dividends, Patel said.

Results of a separate survey released earlier this year showed middle-aged women — those aged 35 to 54 years — have more problematic alcohol consumption patterns but lower awareness about the substance’s effects on breast cancer risk than women of other ages, suggesting this group could benefit from education or other interventions.

Discussions about the cancer-protective benefits of breastfeeding may require more nuance, Patel said.

“This is one area where increased awareness is really important,” she said. “However, it is important that we remember some women — even if they want to breastfeed — are unable to. We need to have the conversation in a way that is sensitive to that. Women should know this is another tool that could lower their cancer risk, but it should not be tied to any guilt or shame if they are unable to do so.”

ACS Cancer Risk 360, a risk assessment tool on the cancer society’s website, is designed to help adults learn what factors — both modifiable and nonmodifiable — may affect their individual cancer risk, as well as the steps they can take to reduce it.

“That is a great starting point to help people understand what they can begin working on, and then clinicians will be critical in helping to push that message,” Patel said.

Alpa V. Patel, PhD, can be reached at alpa.patel@cancer.org.