Although still rare, appendix cancers are increasingly affecting younger generations in the United States, with new research revealing a sharp generational uptick in diagnoses.
A study published Monday in the Annals of Internal Medicine found that compared to older generations, rates of appendix cancer have tripled among Gen X and quadrupled among millennials. These findings, derived from decades of data from the National Cancer Institute’s Surveillance, Epidemiology and End Results (SEER) program, are sparking concerns among oncologists and public health researchers.
“There is a disproportionate burden of appendix cancer among young individuals,” said lead author Dr. Andreana Holowatyj, assistant professor of hematology and oncology at Vanderbilt University Medical Center. “This isn’t just a statistical anomaly — we are seeing real shifts in the generational incidence of this disease.”
A Rare but Rising Threat
Appendix cancer is still extremely rare, with only 1 to 2 cases per million people annually in the U.S. But Holowatyj and her team identified 4,858 cases between 1975 and 2019, a number notable enough to raise public health red flags when broken down by age and generation.
Holowatyj’s earlier research was the first to find that 1 in 3 appendix cancers are diagnosed in adults under 50, compared to just 1 in 8 colorectal cancers in the same age group.
“Given the limited visibility and poor screening options for this cancer, the fact that so many cases occur in younger adults makes it even more concerning,” she said.
An Alarming Pattern Across GI Cancers
Experts suggest this study adds to mounting evidence that gastrointestinal (GI) cancers — including colorectal, pancreatic, and now appendix cancer — are affecting younger adults at growing rates.
“This research fits into a larger, troubling pattern,” said Dr. Andrea Cercek, a GI cancer specialist at Memorial Sloan Kettering Cancer Center, who was not involved in the study. “We’re seeing an increase in early-onset GI cancers, and appendix cancer is clearly part of this trend.”
The underlying causes remain unclear, but many experts point to environmental and lifestyle shifts in post-World War II generations. Possible factors include changes in food processing, diet, chemical exposures, and microplastics.
“You can’t really pin it on one thing,” Cercek said. “It’s most likely a combination of environmental exposures, lifestyle, and genetic susceptibilities converging.”
A Silent Cancer, Often Found Too Late
Unlike colorectal cancers, appendix cancers are notoriously difficult to detect early. They often do not appear on abdominal scans and cannot be identified through routine colonoscopies.
In 95% of cases, appendix cancer is only discovered after a patient undergoes surgery for appendicitis, Holowatyj said.
“By the time the appendix is removed and examined by a pathologist, the cancer may already be in a later stage,” she added.
Dr. Deborah Doroshow, an oncologist at Mount Sinai’s Tisch Cancer Institute, emphasized the challenges this presents for timely diagnosis.
“It’s not about panicking over every stomach ache,” she said. “But if a young person experiences persistent abdominal pain, unexplained weight loss, or fatigue, they should seek evaluation — and be taken seriously by providers.”
Doroshow warned that young women and people of color may face dismissive treatment from healthcare professionals and urged them to advocate for their health.
What Can Be Done?
Currently, there is no standard screening test for appendix cancer, and research into its causes and progression remains limited. However, both Holowatyj and Cercek stress that raising awareness among physicians and patients is a critical first step.
“There’s still so much we don’t know about why this is happening,” Holowatyj said. “But what we do know is that the burden is shifting to younger people — and we can’t afford to ignore it.”
