All posts by : Tetiana Borysenko

For decades, cancer was largely thought of as something that happened to older adults. But that assumption is being challenged — not just by statistics, but by the doctors treating patients every day.

Oncologists across the country are reporting something that would have seemed unusual a generation ago: more of their patients are in their 30s and 40s. More are working. More are raising young children. And more are facing a diagnosis they never expected to receive so soon.

So what’s going on?

The Numbers Are Clear — Even If the Cause Isn’t

According to the American Cancer Society, the number of early-onset cancer cases — defined as cancer diagnosed in adults under 50 — is climbing by roughly 1 to 2 percent every year. A global health data analysis published in the journal BMJ Oncology projects that early-onset cancers will increase by around 30 percent between 2019 and 2030.

Oncologists at the University of Chicago Medicine say they’re seeing this shift directly in their clinics. More patients in their 30s and 40s are being treated for breast cancer, colorectal cancer, and head and neck cancers than in previous years.

High-profile cases have brought public attention to the trend — but behind the headlines, researchers are still working to understand why it’s happening.

What Might Be Driving the Rise?

There is no single confirmed cause. As oncologist Dr. Adam DuVall of UChicago Medicine has noted, the increase is likely the result of multiple factors working together — possibly lifestyle-related, environmental, or both. Current research points to four key areas:

Chronic inflammation The body’s inflammatory response — triggered by low physical activity, obesity, chronic stress, prolonged infections, or ongoing exposure to toxins — may be creating conditions that allow cancer cells to develop and spread more easily.

Gut microbiome disruption The trillions of bacteria living in the human gut play a critical role in regulating immunity and digestion. When that balance is disturbed — potentially by processed foods, microplastics, or other modern exposures — tumors may find it easier to take hold.

Reproductive and hormonal factors Trends toward having children later in life and having fewer children are associated with a modestly higher risk for certain hormone-sensitive cancers, including breast, ovarian, and endometrial cancers.

Healthcare disparities Unequal access to care, nutritious food, and timely medical treatment means that for many people, cancer is more likely to be caught late — or not at all until it has progressed.

The Screening Gap: A Problem That Goes Unnoticed

One of the most overlooked dimensions of this trend is what experts call the screening gap. Standard cancer screening guidelines were built around older populations. Colonoscopies are typically recommended starting at 45. Many other screenings have similar age thresholds.

That means a 38-year-old with early-stage colorectal cancer may have no routine test scheduled to catch it. By the time symptoms appear, the disease may have already advanced.

Dr. Nita Karnik Lee, a gynecologic oncologist at UChicago Medicine, emphasizes that people of all ages should be proactive. If something feels wrong, don’t wait. If cancer runs in your family, talk to your doctor about earlier screening. Symptoms that seem minor — unexplained fatigue, unexpected weight changes, persistent bloating, unusual lumps — deserve medical attention, not dismissal.

“It’s important to identify those warning symptoms and give them attention as soon as possible,” Dr. Lee has said. “If you have a family history of cancer, you may need to get screened sooner. We want patients to advocate for themselves.”

What You Can Do Right Now

While researchers continue to study the causes, there are meaningful steps every adult under 50 can take today:

• Know your family history. Hereditary cancer risk is real. If a parent, sibling, or close relative was diagnosed — especially at a young age — share that information with your doctor.
• Don’t ignore symptoms. Persistent, unexplained changes in your body are worth investigating. Early detection consistently leads to better outcomes.
• Ask about earlier screening. If you have risk factors, you don’t have to wait until the standard screening age. Ask your physician whether earlier testing makes sense for you.
• Consider a multi-cancer early detection test. Tools designed to screen for multiple cancer types from a single test are becoming an important part of proactive healthcare for adults of all ages.

Early Cancer Risk Detection Is the Difference

The rising rate of cancer in young adults is a signal worth taking seriously. But it doesn’t have to be a reason for fear. For the vast majority of cancers, outcomes are significantly better when the disease is found early — before symptoms appear, before it spreads, and while treatment options are most effective.

That’s the principle behind OneTest. A single test designed to detect early cancer risk across multiple cancer types — because cancer doesn’t wait, and neither should you.

Learn more at onetestforcancer.com

Source: UChicago Medicine, “Why are more young people getting cancer? What to know as cases rise,” August 2024. uchicagomedicine.org

This article is intended for informational purposes only and does not constitute medical advice. Please consult a qualified healthcare provider for guidance specific to your health situation.