A study that used data from a community breast imaging facility over an 11-year period found that nearly 1 in 4 breast-cancer diagnoses were in women younger than 50.
The study, presented at the Radiological Society of North America annual meeting, highlights how many younger women with breast cancer may be going undiagnosed.
“Younger women consistently make up a considerable volume of the women diagnosed with breast cancer in our practice, a group for whom there are no screening guidelines at this time,” says the lead author, Stamatia Destounis, MD, a breast imaging specialist at Elizabeth Wende Breast Care in Rochester, New York.
Many Cancers Were Found in Women With No Symptoms
The purpose of the study was to look at trends in breast cancer in younger women, as well as how often this cancer is detected and the types of tumors. The researchers gathered the data from women who visited a community breast-imaging practice consisting of seven outpatient facilities over a 200-mile radius in Western New York.
Researchers found:
- A total of almost 1,800 breast cancers were diagnosed in almost 1,300 women ages 18 to 49 years old between 2014 and 2024.
- Between 20 and 24 percent of all breast cancers diagnosed were in women under 50 years old.
- About 2 in 5 of the cancers (41 percent) were found on routine screening mammograms in women who had no breast cancer symptoms or concerns.
- Close to 3 in 5 (59 percent) were found during diagnostic exams, performed in response to symptoms such as a lump.
Other key findings:
- More than 80 percent of breast cancers were invasive, meaning the cancer had spread beyond its original location in the milk ducts or lobules and begun to invade surrounding breast tissue.
- About one-third were high-grade tumors, meaning they were faster-growing cancers that were more likely to spread.
- Nearly 9 percent were triple-negative breast cancers, an aggressive type of invasive breast cancer that tends to grow faster and spread more than other types of invasive breast cancer. There are fewer treatment options for this kind of breast cancer and typically worse outcomes.
Unfortunately, these findings aren’t surprising, says Destounis.
Mary Beth Terry, PhD, a professor of epidemiology and environmental sciences at Columbia University in New York City, agrees that the findings align with national and global data.
The takeaway from these findings is that “you’re not too young to have breast cancer,” says Dr. Terry, who wasn’t involved in this research, but has coauthored numerous studies on the rise of cancer in younger people, particularly younger women.
Why Breast Cancer Is Increasing in Younger Women
Recent studies have found that early-onset cancer diagnoses in younger people, including breast cancer, have been increasing over the last three to four decades — especially in women.
Destounis points to a number of overlapping causative factors:
- Family history or genetic risk
- Hormonal and reproductive changes, including earlier puberty and later pregnancies
- Increases in body weight and obesity
- Alcohol use
- Early-life factors, such as childhood diet, physical inactivity, infections, antibiotic use, and chemical exposures
- Environmental exposures, including endocrine-disrupting chemicals commonly found in plastics, cosmetics, and cleaning products
“We have been studying a number of endocrine disrupting chemicals (EDCs), and scientists at Silent Spring Institute have identified over 900 chemicals in commonly used products that are relevant to breast cancer causation,” says Terry.
Terry is the executive director of the Silent Spring Institute, a nonprofit research organization dedicated to uncovering the environmental causes of breast cancer.
Findings Make a Case for Personalized Screening in Younger Women
These findings are striking because they show that younger patients make up a substantial share of the women diagnosed with breast cancer, consistently over the study period, and their tumors are often aggressive, says Destounis.
“That combination — steady incidence plus disproportionately aggressive biology — directly challenges age-based screening cutoffs and strengthens the case for earlier, risk-tailored screening approaches,” she says.
This data demonstrate that women under 50, especially those under 40, shouldn’t be seen as low risk by default and can absolutely benefit from risk assessment being performed as early as possible, says Destounis.
Who Should Consider Earlier Breast Cancer Screening?
The American Cancer Society advises starting annual screening mammograms by age 45, with the choice to start between ages 40 and 44.
Factors include:
- A strong family history of breast cancer
- A known genetic mutation such as BRCA1 or BRCA2 or a first-degree relative (such as a parent, brother, sister, or child) with a BRCA1 or BRCA2 gene mutation and no genetic testing themselves
- A lifetime breast cancer risk of 20 to 25 percent or higher
- A history of chest radiation before age 30
- Li-Fraumeni syndrome, Cowden syndrome, or Bannayan-Riley-Ruvalcaba syndrome, or first-degree relatives with one of these syndromes
Symptoms Younger Women Should Watch For
Women should be educated about changes to look for in their breasts that could signal an issue, says Destounis.
- A new lump or thickening in the breast or underarm
- Changes in breast size or shape
- A nipple that turns inward
- Persistent breast pain
- Skin changes such as redness, swelling, or dimpling; in people with brown and Black skin, the breast skin may look darker than other skin on the chest or it may look red or purple
- Peeling, scaling, crusting, or flaking of the skin on the breast
What Experts Want Younger Women to Know
Destounis emphasizes that breast cancer in younger women should not be considered rare or unlikely, and that age shouldn’t be the only factor to consider when deciding when to get screened.
“Paying closer attention to personal and family history, and possibly screening earlier for some women, could help detect these cancers sooner,” she says.