Breast cancer screening

Mammograms can find breast cancer early, often before a lump can be felt.

Rosa: Hi, I'm Rosa. Mammograms can find breast cancer early, often before you can feel a lump. Let's go over when to start and what to expect.

A mammogram is an X-ray of the breast. The breast is pressed between two plates for a few seconds to get a clear picture. This can be uncomfortable, but it is quick. Many centers now use 3D mammograms, also called tomosynthesis, which take pictures from several angles.

The U.S. Preventive Services Task Force (2024) recommends a mammogram every 2 years for women ages 40 to 74 at average risk. Average risk means no strong family history, no known inherited gene change, and no past chest radiation.

The American Cancer Society gives slightly different advice. Women 40 to 44 can choose to start yearly mammograms. Women 45 to 54 should get a mammogram every year. Women 55 and older can switch to every 2 years or keep going every year. Screening should go on as long as a woman is in good health. Talk with your doctor about which plan fits you.

Some people have dense breasts. This means the breast has more firm tissue and less fat. Dense breasts are common and normal. They can make cancer harder to see on a mammogram. Your report may say if your breasts are dense. Ask your doctor whether you need any other tests, like an ultrasound or MRI (magnetic resonance imaging).

Some people are at higher risk. This includes people with a strong family history, an inherited gene change like BRCA1 or BRCA2, or radiation to the chest at a young age. They may need to start earlier and add a yearly breast MRI. Transgender and nonbinary people should ask their doctor what screening fits their body and history.

Being called back after a mammogram is common. Most callbacks do not mean cancer. You may need more pictures or an ultrasound.

Mammogram

An X-ray picture of the breast used to look for cancer.

3D mammogram

A mammogram that takes pictures from several angles. It is also called tomosynthesis.

Callback

A request to come back for more pictures. Most callbacks turn out to be normal.

Dense breasts

Breasts with more firm tissue. This is common, but it can hide cancer on a mammogram.

Breast MRI

A scan that uses magnets instead of X-rays. It is added for some people at high risk.

Know your normal

Tell your doctor about any lump, skin change, nipple change, or discharge, even if your last mammogram was normal.

• Ask your doctor when to start and how often to go.
• Tell your doctor about breast or ovarian cancer in your family.
• Ask if your breasts are dense and what that means for you.
• If you move or change clinics, have your old mammograms sent to the new place.
• Wear a two-piece outfit and skip deodorant or powder on the day of your mammogram.

Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.