Early Onset Cancer Warning
As the incidence of early onset cancers rises, experts double down on screening and prevention
Last reviewed:
Aug. 4, 2025
4 minute read
As the incidence of early onset cancers rises, experts double down on screening and prevention
The likelihood of developing cancer increases as we age, becoming more likely after age 65. However, studies point to a concerning trend — a noticeable increase in “early onset” cancers.
According to Ann Maguire, MD, MPH, internal medicine physician and Medical College of Wisconsin faculty member, the evidence is in the numbers.
“Data during the last 20 years shows an increasing frequency of cancer diagnoses in younger patients,” Dr. Maguire said. “For example, we’re seeing more women who are diagnosed with breast cancer in their 30s and 40s and more people diagnosed with colorectal cancer younger than age 50.”
For some diseases, the increase is dramatic. Between 2010 and 2019, the incidence of gastrointestinal cancer in younger patients jumped nearly 15%.
Cancer experts say the increase in diagnoses is not the result of increased testing. Instead, research points to a complex range of health and social factors.
“The link between cigarette smoking and lung cancer is well documented,” said John Charlson, MD, medical oncologist and MCW faculty member. “With the increase in early onset cancers, it is hard to establish the same kind of definite link, but there is increasing evidence that diet and other lifestyle factors may be implicated.”
Several studies have found that factors associated with early onset gastrointestinal cancers include obesity, alcohol consumption, sedentary lifestyle and diets that are high in red and processed meats and low in fruits and grains.
According to Dr. Maguire, several other theories are being examined. “Some researchers hypothesize that infections may be a factor,” she said. “For instance, we know that hepatitis B can cause liver cancer, human papillomavirus (HPV) can cause cervical cancer and cancers of the head and neck, and a bacteria known as H. pylori can cause gastric cancers.”
One of the most interesting possibilities has to do with changes to microorganisms that live in the stomach, intestines and colon.
“We believe there might be something within the microbiome of the gut that could be playing a role in early onset cancers. This is potentially driven by diets with increased consumption of processed foods,” she said.
What can be done to address early onset cancers? Experts say timely screening is essential.
“The U.S. Preventive Services Task Force has made two major changes in cancer screening guidelines,” Dr. Maguire said. “In the past, the task force recommended that adults start screening for colorectal cancer at age 50. Now the recommendation is age 45. And for breast cancer, the task force previously recommended that average-risk women begin screening at age 50 — now, they advise that screening be offered beginning at age 40.”
Screening should begin even earlier for individuals with a known genetic mutation that raises their cancer risk.
“Women who have BRCA mutations are often characterized by having a breast cancer diagnosis before menopause, sometimes in their 20s and 30s,” said Dr. Maguire, who is also director of the Froedtert & MCW Hereditary Cancer Risk Clinic. “Women with this mutation need to start screening with MRI at age 25.”
Family history is also a factor and may influence the recommended age for cancer screening to begin.
“For example, if someone tells me their father was diagnosed with colon cancer at age 45, this young person will start colon cancer screening at age 35,” Dr. Maguire said.
While physicians within the Froedtert & MCW Cancer Network are working to identify and treat early onset cancers, they also focus on the special needs of these younger people with cancer.
“Younger patients diagnosed and treated for cancer have unique needs compared to pediatric patients or older adult cancer patients,” Dr. Charlson said. “If a person is age 20 or 25 and beats cancer, they potentially have an additional 50 years or more to live, during which they might face late effects of treatment and other issues.”
Dr. Charlson is one of the leaders of the Adolescent and Young Adult Cancer Program, a joint service of the Froedtert & MCW Cancer Network, the MCW Cancer Center and Children’s Wisconsin.
“As part of our focus on caring for young adults, we offer a lot of supportive services,” he said. “We remain available to our patients down the road.”
The good news is that people can take action to reduce their risk of an early onset cancer diagnosis. Dr. Charlson encourages everyone to follow activity guidelines from the American Cancer Society. Every week, adults should get 150 to 300 minutes of moderate-intensity exercise, such as walking at a brisk pace, or 75 to 150 minutes of vigorous exercise, such as running or shoveling snow.
“When it comes to early onset cancers, the guidelines are worth our attention,” he said. “While we cannot completely eliminate cancer risks, we can take steps to reduce them.”
