October 14, 2019

Everything you need to know about mammograms

Confused about breast cancer screening and mammograms? You’re not alone.

Breast cancer screening guidelines are constantly evolving as researchers learn more about the disease. Today, mammograms are still considered the gold standard for screening, but recommended screening schedules vary depending on each woman’s individual breast cancer risk.

Here are answers to some of the most commonly asked questions about mammograms.

What is a mammogram?

A mammogram is an X-ray of the breast used to screen for breast cancer. Mammograms can detect tumors that are too small for you or your doctor to feel and can catch some breast cancers early, when they may be more easily treated.

Are mammograms safe?

Each time you get a mammogram, you are briefly exposed to a very small amount of radiation. While the risk from being exposed to such small amounts is low, some people have concerns.

Alison Sandberg, MD, a breast radiologist at Kaiser Permanente, uses a comparison to put things in perspective for her patients. “I tell them that it takes 3 years of mammograms to reach the average amount of background radiation they get in just one year by living in the United States.”

When should I start getting mammograms, and how often should I get them?

There’s no one-size-fits-all answer. Start by having a conversation with your doctor to determine your individual breast cancer risk. He or she will ask you about your personal and reproductive history and the history of breast cancer in your family.

“This is especially important for women of African American or Ashkenazi Jewish descent, who may be at higher risk,” said Dr. Sandberg.

At Kaiser Permanente, women with average breast cancer risk have the option of beginning annual mammograms anytime in their 40s. For women with above-average risk, recommended screening schedules vary. Talk to your doctor about the benefits and risks specific to your situation.

For women ages 50 to 75 with average breast cancer risk, Kaiser Permanente recommends mammograms every 1 to 2 years. For women ages 75 and up, mammograms are offered in the context of shared decision-making between the woman and her physician.

My mammogram report says that I have dense breasts. Does that increase my breast cancer risk?

All breasts contain glandular, connective, and fatty tissue. Dense breasts have higher amounts of glandular and connective tissue and lower amounts of fatty tissue. Only a mammogram can show if a woman has dense breasts — it can’t be felt in an exam.

Nearly half of all women 40 and older who get mammograms are found to have dense breasts. Dense breasts can make it harder for doctors to evaluate mammogram results and may also be associated with a slightly increased breast cancer risk.

If you have dense breasts, talk to your doctor about any recommended changes to your breast cancer screenings.

Does mammography work?

Yes. Multiple studies have shown a reduction in breast cancer deaths ranging from 20% to 40% with mammogram.

“Mammogram screening works,” said Dr. Sandberg. “What we're doing is saving lives.”

Learn more about breast cancer prevention at Kaiser Permanente.

Graph showing Kaiser Permanente average annual breast cancer screening rate is 84%, compared with the national average of 71%.