A new study shows appendix cancer is rising fast among young adults. Cases have tripled in Gen X and quadrupled in millennials, raising concerns about a hidden health risk in younger generations.

A new study has found that appendix cancer—once considered extremely rare—is rising sharply among younger generations, particularly among Gen X and millennials. The research, published in the Annals of Internal Medicine, shows a troubling trend: younger adults today are being diagnosed with appendix cancer at rates significantly higher than in previous decades.

According to the study, appendix cancer rates have tripled among Gen X and quadrupled among millennials when compared to older generations. This trend raises questions about why more young adults are being affected by cancer traditionally thought to affect the elderly.

“There is a disproportionate burden of appendix cancer among young individuals,” said Dr. Andreana Holowatyj, the study’s lead author and assistant professor of haematology and oncology at Vanderbilt University Medical Center. “Our earlier research was the first to show that 1 in every 3 appendix cancers is diagnosed in adults under age 50. By contrast, only 1 in 8 colorectal cancers are diagnosed in the same age group,” Dr Holowatyj further said. 

Although appendix cancers remain rare—affecting just 1 to 2 people per million each year in the United States—the increase is significant and calls for closer attention. Using data from the National Cancer Institute’s Surveillance, Epidemiology and End Results (SEER) program, Holowatyj and her team examined cancer registry records from 1975 to 2019. They found 4,858 confirmed cases of appendix cancer over that period.

The SEER database covers nearly half the US population and is widely regarded as a reliable source for cancer trends. The researchers noted that a large portion of these cases occurred in people between 18 and 49 years old—a pattern that appears to be growing more common with each generation.

“It’s important that we find the causes underpinning these statistics in order to reverse this trend and reduce the disease burden,” Holowatyj said.

Experts believe that appendix cancer may be part of a larger pattern involving gastrointestinal (GI) cancers in younger adults. Dr. Andrea Cercek, a medical oncologist and co-director of the Center for Early Onset Colorectal and GI Cancers at Memorial Sloan Kettering Cancer Center, said the trend has been observed across different types of GI cancers, including colorectal cancer.

“It’s likely that there are environmental causes—things like food and water contamination, microplastics, lifestyle changes, or dietary habits. It’s probably not just one cause, but a mix of factors that began affecting generations born after 1945,” Cercek explained.

The appendix is a small, finger-like pouch attached to the large intestine. While its function in the human body remains unclear, problems with the appendix can cause serious health issues. Appendicitis—an infection or inflammation of the appendix—often leads to emergency surgery. But in many cases, cancer isn’t discovered until after the appendix is removed and sent to a lab for analysis.

“About 95 per cent of appendix cancers are only found after appendicitis surgery,” said Dr. Holowatyj. “That means they’re often diagnosed at a late stage, which leads to poorer outcomes,” she further added. 

This lack of early detection makes appendix cancer harder to treat effectively. Unlike other cancers of the GI tract, appendix cancer doesn’t show up clearly on abdominal scans and is not typically detected during colonoscopies.

“It’s not easy to detect or screen for appendix cancer,” said Dr. Deborah Doroshow, an associate professor of medicine at the Icahn School of Medicine at Mount Sinai in New York. “That’s why awareness is so important.”

Doroshow, who was not involved in the study, said patients and doctors must be vigilant, especially when younger people report unusual symptoms like persistent abdominal pain, fatigue, or unexplained weight loss.

“If a young person feels something isn’t right, it’s important to take it seriously. We’ve seen cases where young patients were initially dismissed because of their age,” Doroshow explains. 

She also pointed out that women and people of colour may face additional challenges in getting timely diagnoses and must sometimes advocate strongly for their own care.

“That doesn’t mean everyone should panic over occasional stomach pain. But persistent, unusual symptoms shouldn’t be ignored—especially in younger adults,” she added.

As appendix cancer joins a growing list of GI cancers that are striking younger adults, researchers are calling for more studies to explore the environmental and genetic factors driving the trend. Until then, early detection and greater awareness remain key tools in reducing the disease burden.“The rise in appendix cancer is a signal we can’t ignore. The sooner we understand what’s behind it, the better we can protect future generations,” Holowatyj said.