Breast Cancer in Young Women: What to Know

Cancer has long been considered a disease of old age, but a growing number of people are developing it in their 20s, 30s, and 40s. Between 1990 and 2019, the worldwide rate of “early-onset” cancers increased by a staggering 80 percent, and it’s projected to rise another 31 percent in the next ten years.

These cancers don’t affect all young adults equally. Two-thirds of people with early-onset cancer are women, and most of them with breast cancer, says cancer epidemiologist Dr. Mary Beth Terry, executive director of Silent Spring Institute. For decades, Terry has been studying risk factors that lead to the disease.

Early-onset breast cancer is an urgent global problem, she says, and prevention must be a key part of the solution. “We’ve made a lot of progress in treating the disease,” Terry explains. “But, having breast cancer at a young age increases your risk of other health issues like infertility and secondary cancers down the line. We need to focus on reducing the incidence of early-onset breast cancer in the first place.”

Why are more young women getting breast cancer?

There are well-established factors that put women at risk for developing breast cancer. But when it comes to the rise in early-onset, “these factors don’t tell the whole story,” Terry says.

For example, consuming alcohol or having fewer children has been linked with breast cancer, but research shows that early-onset breast cancer is becoming more common even in countries where fertility rates are high and alcohol consumption is rare. Increases and improvements in screening can’t fully explain the situation either, because women generally aren’t screened for breast cancer before age 40.

Evidence for one kind of risk factor, however, is building. “The world has changed a lot in the past several decades. Our environment has become more polluted, plastics and processed foods have become integral to our lives,” Terry says. “We don’t know all the reasons that cancer rates are rising in young people, but harmful chemicals in our food, water, air, and everyday products are emerging as leading culprits.”

Environmental chemicals and breast cancer risk

Studies show that chemicals in our environment can influence the development of breast cancer. Many chemicals do this by altering our hormones. Called endocrine disruptors, these chemicals number in the hundreds and include parabens in lotions and shampoos, phthalates in vinyl, PFAS in food packaging, pesticides, and drinking water contaminants.

For instance, Silent Spring identified more than 900 chemicals that could increase the risk of breast cancer, and other studies by the organization’s scientists have found chemicals associated with cancer in household dust, consumer products, and drinking water.

Scientists are also studying how chemical exposures earlier in life contribute to early-onset. “We’re finding that exposures during ‘windows of susceptibility,’ when the breast tissue is changing, are especially important,” Terry explains. These windows include puberty, pregnancy, and breastfeeding.

As researchers learn more about the chemicals driving early-onset breast cancer, young women won’t be the only ones who benefit: Many breast carcinogens are involved in other types of cancer, as well as chronic conditions such as heart disease and infertility.

“Ultimately, reducing exposure to toxic chemicals helps everyone,” Terry says.

How can I reduce my risk of early-onset breast cancer?

There are a range of ways to protect yourself and others from potential breast carcinogens.

1. Limit your exposure to cooking fumes and car exhaust. Use a fan that vents to the outside when you cook, and support anti-idling regulations and fuel-efficiency standards.
2. Keep dust levels low. Vacuum with a HEPA filter and wipe down surfaces with a damp rag or mop.
3. Be discerning when you buy personal care and household cleaning products. Look for fragrance-free items that don’t contain endocrine disruptors like parabens, phthalates, and benzophenone, and forego chemical hair straighteners and permanent dyes. Check out Silent Spring’s free app, Detox Me, for more guidance. Clearya can also help you interpret product labels.
4. Avoid pesticides. Eat organic as much as possible, and control pests with gels, baits, or sticky traps (rather than sprays).
5. Take action in your community. Join efforts to support a less toxic environment through Toxic-Free Future or the Campaign for Safe Cosmetics.

Resources:

Breast cancer and the environment: Understanding the connection between breast cancer and harmful chemicals in our daily lives—what the science says.

Handout card on environmental chemicals and breast cancer: For healthcare providers and their patients.