Breast Cancer Is on the Rise Among Young Women, Worrying Doctors

Women in their 40s are getting breast cancer in higher numbers, but new mammography guidelines and genetic testing could reverse the trend.

Leslie Grullon (left) and her mother, Merlise Diaz,
Leslie Grullon (left) and her mother, Merlise Diaz, both battled breast cancer. They are now cancer free. Photo: Courtesy of Merlise Diaz/Little Llama Dreams Photography

Merlise Diaz was 43 when she was diagnosed with breast cancer in 2018. Luckily, her treatment (lumpectomy, chemotherapy and radiation) was successful, and she’s been cancer free for six years. Also reassuring was that her daughter apparently wasn’t at elevated risk—her type of cancer wasn’t considered hereditary, genetic testing was negative, and she wasn’t aware of any family history of the disease. “I breathed a sigh of relief,” says Diaz. “I figured my cancer was just a fluke.”

But four years later, her daughter, Leslie Grullon, 29, started experiencing night sweats and a shooting pain in her breast. She was diagnosed with a different type of cancer than her mother’s and required a double mastectomy. “I thought, This can’t be happening,” says Diaz. “‘Lightning doesn’t strike twice.’” Her daughter endured five breast-reconstruction surgeries, but has been cancer free for three years. Despite struggling with anxiety following her ordeal, she plans to pursue a career in nursing.

Alarming jump

While this mother-daughter story is, thankfully, quite unusual, it does reflect a disturbing trend: The incidence of breast cancer in young women is rising. According to the U.S. Preventive Services Task Force, the number of women in their 40s diagnosed with breast cancer increased by 2 percent a year between 2015 and 2019. Doctors like Bonni Lee Guerin, a hematologist and oncologist who is director of the Breast Cancer Treatment and Prevention Program at Overlook Medical Center in Summit, are particularly alarmed by the increase among Black women in their 20s. “Their chances of getting breast cancer has jumped to double what it was just 5 or 10 years ago,” she says. “That’s mind-blowing.”

Why the numbers are rising for younger women is “the million dollar question,” says Guerin. “The truth is that nobody knows.” Some of the increase may simply be because more women are getting mammograms as there’s more awareness of their importance, so more cancers are being detected, says Dr. Arnold Baskies, past chairman of the national board of directors of the American Cancer Society and a clinical professor of surgery at Rowan University School of Medicine in Stratford. In addition, he says, during the pandemic, many women deferred having mammograms, which could account for a post-pandemic bump in cases.

Obesity’s role

For her part, Guerin believes that childhood obesity, which has jumped in the past 20 years, largely drives the early-age onset of breast cancer. “Women in their 20s are the first cohort of women that experienced the prevalence of childhood obesity,” she says. “We get some estrogen from adipose tissue; the larger your fat cells, the higher your estrogen level. And we absolutely know there is a strong link between obesity and breast cancer; unopposed, relentless, long-term estrogen increases your risk. “

The rise among young Black women is also “a puzzle,” she says. Deepening the mystery is the fact that, while a Black woman in her 20s has twice the risk of a white woman, by the time she’s 40, her risk is equal to her white peers. “Why would it be that, not only would a Black woman have an earlier onset of breast cancer, or we’d see it earlier, but why is it in the 20s and then it seems to dwindle away by the time she’s in her 40s?” asks Guerin.

With breast cancer the second most common cause of cancer deaths among U.S. women, making up 30 percent of all new cases according to the American Cancer Society, any increase is cause for concern. The group estimates that one in eight women will develop the disease in the course of their lives.

Also troubling is the fact that young women diagnosed with breast cancer tend to have poorer prognoses than older women, says Guerin. The absence and shortcomings of mammography in younger women likely play a part. “Younger women may not be getting mammograms as routinely as they should and so can be diagnosed at a later stage, when tumors are bigger. Also, tumors in younger women are generally worse, more estrogen negative, which tend to have poorer prognoses and are more likely to be involved with the lymph nodes.” In recent years, screening mammography had only been recommended for women age 50 and older.

Even if a woman in her 40s or younger does get a screening mammogram, detecting early evidence of cancer on mammograms is more difficult in younger women, who tend to have dense breast tissue. (Dense breast tissue shows up as white on mammograms, as do cancerous growths, so it can be hard for radiologists to distinguish between the two.) For the same reason, mammography readings are also less useful for diagnostic purposes in younger women. And since they don’t have previous mammograms to compare them to, detection and diagnosis are further hampered.

Mammograms matter

Fortunately, due to these concerns, the age recommendations for screening mammograms have changed. In April 2024, the U.S. Preventive Services Task Force, which many primary care doctors rely on for testing guidelines, began advising that women get screening mammograms every other year beginning at age 40, rather than 50. Other groups, including the American Cancer Society, also lowered their starting age to 40-45, with yearly mammograms.

Though there is some discrepancy in the recommendations, the important point is to discuss your family history with your health care provider by around age 40 and have annual mammograms by at least age 45, says Baskies. The conversation should be ongoing, since family histories change, says Guerin. “Young women are not thinking about their family trees, nor are the physicians. But it’s an opportunity to find out if you’re a carrier of a breast-cancer gene. And among younger women, there’s a higher chance a breast cancer is linked to a genetic mutation.”

The most common genetic mutation, the BRCA1 gene, puts carriers at very high risk of developing breast cancer. If your family history indicates that a genetic test is warranted and you discover you are a carrier, most insurance carriers will pay for a breast MRI along with your mammogram, which is much better than mammography alone at picking up early signs of cancer.

Illustration of woman reaching for just out-of-reach pink ribbon symbolizing breast-cancer awareness

Illustration: The Brave Union

Going back in time

When researching your family history, go back three generations—even a grandmother or great aunt with breast cancer increases your risk, says Guerin. Third-degree relatives, such as first cousins, also count. And don’t focus exclusively on female relatives or breast cancer. Pancreas, prostate and uterine cancer, for example, share risk genes with breast cancer. Ethnic background, such as being an Ashkenazi Jew or of Eastern European descent, also elevates your risk of developing breast cancer.

In the new recommendations, there is no mention of monthly breast self-exam. According to the American Cancer Society, research has not shown a clear benefit to regular physical breast exams done by either health professionals or by women themselves. But that doesn’t mean they’re not an important preventive tool. In fact, the society adds that, “most often, when breast cancer is detected because of symptoms (such as a lump in the breast), a woman discovers it during activities such as bathing or dressing. Women should be familiar with how their breasts normally look and feel and should report any changes to a health care provider right away.”

Merlise Diaz and her daughter both credit familiarity with their breasts, gained from self-exams during showers, with helping them recognize a difference when lumps developed. “I recommend to all my very young patients to do breast exams, not because I think they’re going to find something, but because it helps keep breast health on the forefront of their minds,” says Guerin.

The news about breast cancer is not all bleak. Although the incidence of the disease is increasing, far fewer women now die from the disease. In 1975, for example, the five-year survival rate was 75 percent; it is now about 93 percent. Baskies attributes this to improved detection techniques, surgery, and drugs. For instance, doctors can now analyze the genetic material from a biopsy to determine the most effective treatment. “It’s pretty amazing,” he says. “We used to think what was important was the size of the tumor or whether it had spread to the lymph nodes. But what kills a woman is if the disease spreads beyond the breast. This test actually tells you whether or not it has the potential to do that. It’s the answer we’ve been looking for.”

REDUCE YOUR RISK

A healthy lifestyle can decrease your risk of getting breast cancer, and improve your outlook if you do, at any age. Here’s the latest research-based advice from the American Cancer Society:

Don’t drink

Drinking alcohol is clearly linked to an increased risk of breast cancer. The risk increases with the amount of alcohol consumed. One drink a day has a 7-10 percent increase in risk; two to three drinks a day, about a 20 percent higher risk. Limit yourself to one drink a day at most.

Maintain a healthy weight

Having more fat tissue increases the amount of estrogen your body makes, which raises your risk. Women who are overweight also tend to have higher levels of insulin, which has also been linked to breast cancer.

Stay physically active

Exercising and limiting sedentary behavior reduces breast cancer risk. Aim for at least 150-300 minutes of moderate intensity or 75-150 minutes of vigorous activity each week.

Eat a healthy diet

Include a variety of vegetables, especially leafy greens, beans, fruit and whole grains. Limit red and processed meats, sweetened beverages, processed foods, and refined grain products.


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