• A new study explored the differences between tumors in younger and older colon cancer patients.
• Younger patients sometimes had more aggressive, treatment-resistant forms of colon cancer.
• Staying active, cutting down on processed foods, and getting screened are good ways to lower risk.

People under 50 aren't only at a higher risk of colon cancer today than they were a few decades ago. They're also developing a different, sometimes more aggressive form of it compared to older patients, scientists say.

A new study published in Nature Medicine analyzed 189 tumors from colorectal cancer patients aged 29 to over 90, including measurements of gene activity in more than 850,000 cancer cells.

The goal was to look at how tumors varied "across the entire spectrum of age," Dr. Ana Anderson, a co-senior author of the study who leads the cancer immunology program at the Gene Lay Institute at Brigham and Women's Hospital in Boston, told Business Insider. "Is it the same colon cancer but just happening in younger people, or is there something different about it?"

As a result, the study was able to map out gradual, subtle differences in colorectal cancer tumors correlated with age. While the researchers couldn't pinpoint exactly why tumors in younger people look different, Anderson said the study is an exciting starting point for further research.

"There's a lot of interest in lifestyle factors and environmental exposures as potential contributors; however, nothing specific has been pinned down," Anderson said. "What we did is take a rather simple but comprehensive approach just to try to understand the disease itself."

Younger patients' tumors had a different cellular makeup

The study's researchers couldn't definitely state that colon cancer in younger patients is always more aggressive — that would require more study.

However, what they did find was that younger patients "generally have more aggressive disease and they are generally more resistant to the standard of care therapies, which is mostly chemotherapy," Anderson said.

Tumors in younger patients generally had a higher presence of supporting and connecting cells known as stromal cells. Stromal cells, such as fibroblasts, can produce factors that suppress the immune response, making it harder for chemotherapy drugs to work. "They essentially can form a shield that protects the tumor from infiltration," Anderson said.

The study found that the presence of stromal cells generally declined from younger to older patients, and the youngest patients tended to have the highest number of stromal cells in proportion to cancer cells.

The reverse was true for the oldest patients, who generally had the fewest stromal cells and the highest numbers of cancer cells.

Researchers narrowed down where to look for answers

Younger patients also had higher activity of long non-coding RNAs (lncRNAs), which are associated with cellular signaling in cancer. The study also found gene activity in younger patients that suggested stronger signaling between cells — potentially helping cancer cells move and invade nearby tissue.

The problem is, lncRNAs are still a fairly recent discovery; they only became linked to cancer research in the late 2000s, with some poorly understood ones referred to as "dark RNAs." "A lot of them have just not been researched, and that's why they're called 'dark RNAs' — it's a big mystery," Anderson said.

For that reason, she said it was the finding she considered most promising. "There's a world of biology to be discovered there — we know where to focus our research efforts," she said.

Anderson, an immunologist, also hopes to explore the presence of immune cells in younger colon cancer cases, as immune cells are involved in killing cancer cells but were "under-captured" in this study, she said. "There are many types of immune cells," she said. "Are there different subsets that are more present in the young tumors or absent in the young tumors versus the older tumors?"

Reduce your risk with these simple habits

While the study doesn't present any immediate new takeaways for young people concerned about colon cancer, Anderson suggested following existing guidance for lowering your risk.

She noted that the recommended screening age for most people was lowered from 50 to 45 a few years ago, but that it's wise to see a doctor sooner if you experience common colon cancer symptoms like rectal bleeding, abdominal pain, bloating, or changes in bowel movements.

If you're "extra cautious," she said, it's never a bad idea to stay active and cut down on inflammatory foods such as ultraprocessed snacks and alcohol.

• Azucena "Suzy" Reyes went to the ER several times for nausea and stomach pain.
• After months of back and forth, she finally learned she had a mass in her large intestine.
• Despite first being told she was 'too young' for colon cancer, she was diagnosed at stage 3B.

No matter how healthy she tried to eat or how often she ran 4 miles at her community college, Azucena "Suzy" Reyes felt bloated in her stomach.

"I looked like I was pregnant," Reyes, who's 43 and based in Alvin, Texas, told Business Insider. At 32, she was studying to be a certified nurse assistant while running a construction company with her husband and raising their four children together.

Then, her symptoms got worse. She was frequently exhausted, which she attributed to working out and being busy. She started getting fevers and feeling intense nausea. There was also her severe stomach pain.

"I really thought it was an ovary that had burst because it was that painful," she said.

Between August and October in 2015, Reyes went to the ER four times, originally diagnosed with inflammation in her intestines. When she finally saw a GI doctor in October, she was sent to the ER a fifth time, where she had emergency surgery and learned she had stage 3 colon cancer.

"I was scared because I did not know anything about colon cancer," Reyes said. "It was very, very dramatic to me because I didn't want my children to go through the fear of thinking that I was going to die."

She was told she likely didn't have cancer because of her age and race

After the ER staff looked at her vitals, Reyes was first diagnosed with colitis and enteritis, inflammation of the small and large intestines, as well as a microperforation. She was sent home with antibiotics. When the pain didn't go away, she returned to the ER and was put on a PICC line to administer medication and kept in the hospital for three weeks. Around the same time, Reyes tried to book a GI appointment and was put on a waitlist until early October.

When the PICC line was removed, the nausea came back. The next two ER visits didn't yield more answers. By the time she finally saw her GI, she couldn't keep still long enough because she kept throwing up.

Within hours, Reyes and her husband went to the ER a fifth time, where an ultrasound revealed a tumor that had completely obstructed her transverse colon, the longest part of her large intestine, and made it difficult for her to keep food down. The next morning, she had emergency surgery to remove it.

At first, Reyes said, the surgeon told her not to worry about the tumor. He told her she was very young, and that colon cancer wasn't as common in Hispanic populations and people under 60.

But a week later, she learned she had stage 3B colon cancer. "I was scared, but then relieved at the same time," Reyes said. "For three months, I was suffering, and I didn't know why."

Worried about worrying her family

The original plan was to hide her diagnosis and treatment from her family, especially her four kids, ranging in ages from 4 to 16 at the time. The doctor said she would likely only need two or three rounds of chemotherapy. Reyes and her husband wanted to leave their children with her mother and say they were going on a long couple's trip for about a month.

Once she met with her oncologist and learned that the cancer had grown through her muscular wall and into her lymph nodes, she learned she would need 12 rounds of chemotherapy — about six months of treatment. It would be impossible to keep a secret. "I just didn't want anybody to suffer, like my children and my parents," Reyes said.

Reyes experienced side effects from the chemo, such as nausea, fatigue, and weight gain. "I was literally swollen," she said. "It's like they pumped air into me."

All the while, she avoided looking up colon cancer or trying to research her prognosis online — something she said helped her maintain a "peace of mind" throughout treatment.

She now advocates for cancer awareness in Spanish-speaking communities

As of October 2026, Reyes has been cancer-free for over a decade. She says she continues to receive annual follow-ups, including colonoscopies, blood work, and CT scans.

Some of her treatment side effects haven't gone away. "The neuropathy in my feet, arms, fingers — it just feels like needles poking them," she said.

After she was diagnosed, she urged her brother, who was 42 and a few years below the recommended screening age of 45, to get a colonoscopy. After some resistance, he agreed — and learned he had colon cancer as well. After surgery to remove his tumor, he's been cancer-free for 4 years, she said.

Looking back, Reyes said she had wanted more guidance from other people who had colon cancer. She remembered posting about her experience on social media, but "nobody ever reached out to me and said, 'Hey, I'm an advocate for colon cancer. I'm here,'" she said. "I wish I would've had that."

Reyes is now involved with the Colorectal Cancer Alliance's Never Too Young Taskforce, as well as a few other groups. She also tries to focus on helping the Spanish-speaking community. "There are so many people that come out to us, me and my husband, and they're like, 'Thank y'all for doing this,'" she said.

After Bryce Ramsey was diagnosed with stage 3 colon cancer at 33, she learned another piece of shocking news: She had a genetically high chance of developing it from the very beginning.

Ramsey tested positive for Lynch syndrome, a silent, inherited condition that heightened her lifetime risk of being diagnosed with colorectal cancer by up to 56% for her variant. It also put her at greater risk of developing ovarian, uterine, stomach, pancreatic, and other forms of cancer.

Before she learned she had Lynch, Ramsey urged her relatives to also get screened for colon cancer. Since then, her father, brother, and aunt have all been diagnosed with various stages of colon cancer. Like Ramsey, her aunt also tested positive for Lynch.

"I was the whistleblower," Ramsey, 40, based in Mississippi, told Business Insider. Ramsey now wants her two young sons to test for Lynch once they're in their early 20s, the recommended starting age for her specific Lynch mutation.

Like most genetic testing, Lynch syndrome testing is relatively quick, cheap, and non-invasive. It involves a saliva test, a cheek swab, or a blood test, with the latter having the least room for error.

Still, it hasn't caught on: About 1 in 279 Americans (1.2 million people) are estimated to have Lynch syndrome, including between 3 to 5% colon cancer patients. Yet an estimated 95% of Americans with Lynch syndrome have no idea they have it.

All the while, cases of colon, breast, uterine, and pancreatic cancers are rising in young people, with colon cancer the deadliest cancer for adults under 50. "If you don't know, then you can't get help," Ramsey said, including earlier screenings or preventive measures such as hysterectomies.

"Ignorance is not always bliss."

The 'lowest hanging fruit' for cutting down cancer risk

Some experts view broader Lynch syndrome testing as a way to get more people screened for cancer before symptoms arise — and a way to potentially help entire families better understand their cancer risks.

Like Ramsey, the majority of people diagnosed with Lynch syndrome only get screened after they have cancer. In the US, the CDC's general guidelines recommend that colon and uterine cancer patients have tumors biopsied for Lynch, followed by Lynch syndrome screening for the patient if there are abnormal findings.

Some experts believe the lack of early genetic testing is a huge missed opportunity for reducing cancer risk. One 2021 study found that about 16.4% of 713 early-onset colorectal cancer cases could have been prevented if patients knew either their family history or had been genetically screened, and would have subsequently started getting colonoscopies sooner.

Lynch syndrome testing "has got so much potential, but it's not being utilized," Heather Hampel, a professor at City of Hope in California who specializes in clinical cancer genomics and Lynch syndrome, and a co-author of the study, told Business Insider.

While Lynch syndrome remains unknown to most Americans, some health systems are trying to expand testing to the broader population. Helix, a genetic screening company that first started out as a consumer DNA marketplace, started partnering with 17 health systems in 2021 as part of its "Population Genomics Initiative." The goal has been to introduce broader population-scale genomic programs that include testing for Lynch syndrome.

Dr. Cassie Hajek, the medical director of Helix, told Business Insider that most patients diagnosed with one of these hereditary conditions by Helix were completely taken aback by the news. "They're kind of operating on the assumption that their risk is just as it is in the general population, but in fact, it's significantly elevated," she said. "The whole goal is to identify these patients hiding in plain sight."

By knowing their genetic predispositions for cancer, they can both more easily start earlier cancer screenings and also inform their family members of their potential genetic risks.

Hampel noted that lowering overall cancer rates is complicated. We still don't know why colon cancer cases are rising so rapidly among young people, and lifestyle factors like sedentary routines and diets high in ultra-processed foods are far more difficult to control for.

"If the lowest-hanging fruit is family history and gene testing, and we can't even prevent those," Hampel said, "how are we ever going to prevent things where we need people to make lifestyle or behavioral changes?"

The ripple effects for families

Michelle York was 33 when she first heard of Lynch syndrome.

Up until that point, all she'd known was that her mom's side of the family had a long cancer history. Her great-grandmother died from colon cancer. Her grandfather had stomach and brain cancer. Her great-aunts died from liver, ovarian, and breast cancer, respectively. Her mother's cousin died from pancreatic cancer.

York's mother, a nurse at the time, had come across the term through her work. She tested positive for Lynch, along with York, her two siblings, aunt, uncle, and cousin.

At first, the news caused some anxiety. "Does this mean I'm going to get cancer at a young age?" York, 43 and based in Los Angeles, told Business Insider. "Does this mean every time I don't feel well, I'm going to immediately think I have cancer?"

However, once York and her family started getting routine cancer screenings, including annual colonoscopies, they felt more reassured than afraid, because they knew they could catch cancer early. York's mother had multiple precancerous polyps removed.

"None of us have had cancer yet, but we've had lots of scares," York said. She also wants her kids, ages 17 and 14, to test once they're older.

York's mother triggered something called "cascade testing," in which other family members test for Lynch and can take preventive measures to reduce their cancer risk.

Dr. Sapna Syngal, the director of research at the division of cancer genetics and prevention at the Dana-Farber Cancer Institute in Boston and the founder of its Lynch Syndrome Center, sees cascade testing for Lynch as a "real opportunity" to lower cancer risk, she told Business Insider.

Particularly for young people, if they test positive for Lynch in their 20s and start getting cancer screenings, "there's a really, really good chance that you could prevent that cancer by taking out polyps earlier on," she said.

There are also financial benefits to knowing you have a genetic predisposition to cancer. While insurance coverage for Lynch-related cancer screenings can vary, Hajek said her patients typically have a more "straightforward" experience in getting otherwise expensive screenings like colonoscopies covered. York, for example, said her insurance covered her cancer screenings once she got her Lynch syndrome diagnosis.

Ultimately, Hajek said Lynch syndrome testing can help patients get more precise care than simply knowing they have a family history of cancer. Just as testing positive for Lynch can prompt someone to start cancer screenings sooner, testing negative can also relieve a person of anxiety about being at high risk of early-onset cancer and potentially call for less frequent cancer screenings than if they had Lynch.

York said she's ultimately grateful for finding out and knowing she can catch any early signs of cancer by starting annual screenings such as colonoscopies in her 30s — over a decade before the average-risk recommended screening age of 45. Both Ramsey and York also had hysterectomies and oophorectomies unrelated to cancer, which brought extra relief in also reducing their uterine and ovarian cancer risks to essentially zero.

"I think knowledge is power," York said. "Now, it almost feels comforting because I know that I started doing this young."

Lynch needs its Angelina Jolie

In 2013, Angelina Jolie revealed in a New York Times op-ed that she had tested positive for BRCA1, a gene that increases the risks of breast and ovarian cancer.

Her revelation — and subsequent operations to remove her breasts and ovaries — sparked an international drive to get tested for BRCA1/BRCA2. Years later, a study found that 15 business days after Jolie's op-ed went live, BRCA testing rose 64% in the US.

Over a decade later, researchers and patients are working to make Lynch syndrome screening similarly universal.

Getting every person screened comes with its own obstacles.

Lynch could be added to the list of genetic conditions screened for in newborn heel tests. However, critics of the idea believe it can create years of stress when the person with Lynch isn't recommended to start getting colonoscopies until they're in their early 20s.

Other routes, such as including Lynch syndrome testing when people join the military or go to college, would miss broad swaths of the population.

There's also the question of funding. Helix, for example, doesn't bill patients and instead relies on the participating health systems for financial support. Few hospital systems can afford to prioritize testing for a gene condition that impacts a small portion of the population.

Syngal said one immediate option for getting more people screened for Lynch is to follow York's route: consider getting tested if you have a family history of colon or other relevant cancers.

Since their diagnoses, Ramsey and York have tried to spread the word about Lynch syndrome testing. Ramsey is an official advocate for the non-profit Lynch Syndrome Awareness, while York, a full-time content creator, has shared her story on social media.

"It's scary when you first find out that you have a genetic mutation that predisposes you to cancer," York said. "But at the end of the day, knowing that and taking those precautions could ultimately save your life."