Beating breast cancer: The latest on prevention and screening

There’s good news on the breast cancer front: Advances in medicine are helping more women than ever survive a breast cancer diagnosis.

Death rates for the disease have been declining for nearly 30 years thanks to better screening and advances in treatment. The survival rate for women diagnosed with breast cancer is now around 90 percent, and even higher when it is detected in the earliest stages.

Patient care is improving, too, with oncologists now often able to personalize a breast cancer diagnosis and its treatment.

Yet the incidence of breast cancer remains stubbornly consistent. Roughly 1 in 8 women will develop the disease over the course of her lifetime. Men also can contract the disease. So how best to protect yourself? For Breast Cancer Awareness Month, we checked with experts across the University of California for the latest advice.

Healthy habits help

Scientists still don’t know the exact causes of breast cancer, but it’s becoming clear that multiple factors often interact to contribute to the disease.

Some of the biggest risk factors are ones you can’t control, like genetics or age. But there are plenty of ways you can take action to reduce your risk:

  • Avoid alcohol and tobacco products: An analysis of data from 53 studies found that for each alcoholic drink consumed per day, the relative risk of breast cancer increased by about 7 percent; women who had two to three alcoholic drinks per day had a 20 percent higher risk of breast cancer;
  • Get regular exercise: In one study from the Women’s Health Initiative, as little as 1.25 to 2.5 hours per week of brisk walking reduced a woman’s breast cancer risk by 18 percent; the American Cancer Society recommends that adults get at least 150 minutes of moderate intensity or 75 minutes of vigorous intensity activity each week; and
  • Maintain a healthy body weight: Women who are overweight or obese after menopause have a 30 to 60 percent higher breast cancer risk.

Want to know more? Check out this interactive breast cancer causation model created by a UC San Francisco team led by Robert Hiatt and funded through UC’s California Breast Cancer Research Program. It illustrates the various factors that influence breast cancer risk.

Surprising factors

Some surprising research over the past year points to other ways to limit breast cancer risk, including limiting late night snacking and avoiding personal care products that contain hormone-disrupting chemicals.

A decrease in the amount of time spent eating each day and an increase in overnight fasting reduces glucose levels and appears to also reduce the risk of breast cancer among women, UC San Diego researchers reported.

Another step: Try to avoid personal care products that contain chemicals such as phthalates, parabens, triclosan and oxybenzone. These chemicals are widely used in personal care products, including cosmetics, fragrance, hair products, soaps and sunscreens, and have been shown in animal studies to interfere with the body’s endocrine system.

“Teen girls may be at particular risk since it’s a time of rapid reproductive development, and research has suggested that they use more personal care products per day than the average adult woman,” said UC Berkeley researcher Kim Harley, lead author of a study on the subject.

Pregnant women also should limit exposure to certain chemicals. It’s not just their own health at risk but that of their children, and even grandchildren, according to the groundbreaking Three Generations Study (3Gs). Funded by the California Breast Cancer Research Program, the ongoing study is analyzing the role of fetal exposure to pesticides, household cleaners and other pollutants in developing breast cancer as an adult. Initial findings show a relationship between pesticide exposure in the womb and developing breast cancer later in life. This is the first study to substantiate the theory that the chemicals a pregnant woman is exposed to can lead to cancer in her daughter, or even her granddaughter, years later.

Screening guidance

Regular breast cancer screening is another good prevention measure, but lately the news has gotten more confusing about how often women should have mammograms.

A new UC Davis report, done in partnership with the state Department of Public Health, found that too few Californians are getting screened for breast cancer and other types of cancer.

“As a result, many persons are not being diagnosed until their cancers have progressed to an advanced stage,” said senior author Kenneth Kizer of UC Davis. “We need to increase cancer screening efforts to save lives.”

Oncologists now recommend that women tailor their screening decision to their own specific circumstances by talking with their doctor about their family history and their breast tissue density (which can make imaging techniques, like mammograms, less effective.)

A study co-led by UCSF researchers found that women at high risk who also have dense breast tissue may benefit from annual screenings — more frequent than current guidelines, which call for mammograms every two years. Women at average risk with low breast density would be best served by screenings every three years. And women with average risk and high breast density would do equally well with screenings every two or three years.

To assist women and their providers in determining breast cancer risk, the Breast Cancer Surveillance Consortium has developed a risk calculator, which is the only calculator that also incorporates a clinical measure of breast density – a key screening determinant in this study.

“Our whole goal is to tailor breast cancer screening,” said UCSF’s Karla Kerlikowske, co-first author of the National Cancer Institute-funded study.


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