What Joan Lunden's Story Can Help Us Understand About Breast Cancer and Dense Breasts

The ultrasound after the clear mammogram

In June 2014 Joan Lunden, who co-hosted Good Morning America from 1980 to 1997, told the public she had breast cancer. She was 63. She announced it in a letter on her own website and then in interviews.

She told CNN that her annual mammogram had come back clear. A precautionary ultrasound the same day found a small spot, and a biopsy followed. Doctors found two small tumors in her right breast. The type was triple-negative breast cancer. She said she had no symptoms and no family history of the disease.

She also told CNN what her doctors had planned: chemotherapy first to shrink the tumor, then a lumpectomy, then radiation. She has since said repeatedly that every breast cancer is different, and that no two plans should be expected to match.

In October 2024 she told ABC7 New York she had been free of cancer for ten years, and that she had spent the decade pressing for women to be told their breast density.

That is what she has made public. The rest of this page is about the disease, not the person.

What breast density is

Breasts hold glandular tissue, which makes milk; fibrous connective tissue, which holds the breast together; and fat. Density is the balance between them on a mammogram. Dense breasts have more glandular and fibrous tissue and less fat.

NCI says dense breasts are common. Close to half of all women aged 40 and over who have a mammogram are found to have them. Density is often inherited, tends to fall with age and after childbirth, and rises with menopausal hormone therapy and a low body mass index.

You cannot feel density. Neither can a doctor doing a breast exam. Only a radiologist reading your mammogram can tell you.

Radiologists sort density into four groups using a system called BI-RADS. About 10% of women have almost entirely fatty tissue and about 40% have scattered dense areas. Another 40% are heterogeneously dense, and about 10% are extremely dense. The last two groups are what "dense breasts" means on a report. Our guide to breast density walks through the wording you may see.

Why it matters for a mammogram

On a mammogram, fat looks dark. Dense tissue looks white. So do calcium deposits and tumors. A white tumor sitting in white tissue is harder to see.

NCI puts it plainly: mammography is less sensitive in women with dense breasts, meaning it is more likely to miss a cancer. Women with dense breasts also get called back for extra pictures more often.

Density is separately a risk factor: women with dense breasts have a higher chance of developing breast cancer than women with fatty breasts. That risk is not the same thing as the reading problem.

The harder question is what to do about it. NCI points to the U.S. Preventive Services Task Force, which has found there is not yet enough evidence to recommend for or against adding ultrasound or MRI for women with dense breasts. So this is a conversation with a clinician rather than a settled rule. Our page on supplemental screening for dense breasts sets out what those extra tests can and cannot do.

What "triple negative" means

Breast cancers are sorted by three markers: the estrogen receptor, the progesterone receptor, and a protein called HER2. Treatment depends heavily on which of the three a tumor carries.

Triple negative means the tumor has none of them. That rules out hormone-blocking drugs and HER2-targeted drugs, so treatment leans on chemotherapy. Our page on triple-negative breast cancer covers the pathology report in more detail.

For stage II and stage III triple-negative disease, NCI's health-professional summary describes giving drug treatment before surgery. In the KEYNOTE-522 trial, patients got chemotherapy plus either the immunotherapy drug pembrolizumab or a placebo. In the first 602 patients, 64.8% on pembrolizumab had no cancer left in the tissue removed at surgery, against 51.2% on placebo. At a median of 39 months, 84.5% of the pembrolizumab group were alive without their disease returning, against 76.8% on placebo. Serious side effects were more common with pembrolizumab: 32.5% versus 19.5%.

The numbers, and what they are not

The American Cancer Society projects 321,910 new US cases of female breast cancer in 2026 and 42,140 deaths, a forecast SEER carries alongside NCI's own measurements. Five-year relative survival across all stages, for cases diagnosed in 2016 through 2022, is 91.9%. The median age at diagnosis is 64.

By how far the cancer had spread at diagnosis: 64% are found while still confined to the breast, with five-year relative survival of 100.0%. For the 27% found in nearby lymph nodes it is 87.5%, and for the 6% found after spread to distant organs it is 33.8%.

These are averages across large groups of people treated in past years. They do not forecast anything for one person, and they do not separate out triple-negative disease.

When to get checked

Do not wait on any of these:

• A new lump or thickening in the breast or armpit that does not settle over a menstrual cycle
• Skin on the breast that dimples, puckers, thickens, or looks like orange peel
• A nipple that turns inward, or crusting and scaling around it
• Clear or bloody discharge from one nipple, without squeezing
• One breast changing shape or size while the other does not

If you have already had a mammogram, ask what it said about your density, and ask what that means for your own plan. Our page on why mammograms miss some cancers explains where the gaps are.

What this does not mean

• Dense breasts are not a diagnosis and are not abnormal. Around half of women who get mammograms have them.
• A clear mammogram does not rule out cancer, and this is not an argument against having one. Mammography is still the test with the strongest evidence behind it.
• Research has found that people with breast cancer who have dense breasts are no more likely to die of it than people with fatty breasts, once other health factors and tumor features are accounted for.
• One person's treatment path is not a template. The three markers, the stage, and the individual all change the plan.

Sources

• CNN, Joan Lunden, former "GMA" host, talks about her breast cancer diagnosis — https://www.cnn.com/2014/06/27/health/joan-lunden-cancer-gma
• ABC7 New York, 10 years cancer-free, Joan Lunden urges women to be aware of breast density — https://abc7ny.com/post/breast-cancer-awareness-month-joan-lunden-reflects-10-years-after-beating-disease-urges-women-aware-density/15379170/
• NCI, Dense Breasts: Answers to Commonly Asked Questions — https://www.cancer.gov/types/breast/breast-changes/dense-breasts
• NCI PDQ, Breast Cancer Treatment (Health Professional Version) — https://www.cancer.gov/types/breast/hp/breast-treatment-pdq
• SEER Cancer Stat Facts, Female Breast Cancer — https://seer.cancer.gov/statfacts/html/breast.html

How this article was prepared

An AI-assisted editorial system helped prepare this page. No named medical reviewer has reviewed it unless one is listed.

The National Cancer Information Foundation publishes Cancer Explained. This page is for learning. It is not medical advice and does not suggest a test or treatment.

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