Science Pulse

Appendix cancer is still very rare, but researchers are seeing a sharp rise in cases among younger adults.

Recent research in the United States found that Gen X and Millennial adults are three to four times more likely than older generations to be diagnosed with this cancer. Today, about 1 in 3 people with appendix cancer are diagnosed before age 50.

A 2020 national analysis led by epidemiologist and molecular biologist Andreana Holowatyj found that malignant appendix cancer cases in the United States rose by 232 percent between 2000 and 2016. Two newer peer-reviewed studies also found that cases tripled among Americans born from 1976 to 1984 and quadrupled among those born from 1981 to 1989, compared with people born from 1941 to 1949.

Doctors do not yet know what is driving the increase. Possible factors include diet, physical activity, inherited gene variants, environmental exposures, chemical pollution, microplastics, poor sleep, alcohol use, and ultra-processed foods.

The cancer can be hard to detect because symptoms often look like more common problems. Abdominal pain, bloating, pelvic pain, hernias, fibroids, cysts, and endometrial-like lesions can all confuse the diagnosis.

There are only about 3,000 appendix cancer cases each year in the United States, compared with roughly 150,000 colorectal cancer cases. Because it is so rare, appendix cancer has fewer screening guidelines, less awareness, and more limited treatment options.

Experts say people with persistent or unusual abdominal or pelvic symptoms should speak with a health care professional. Early diagnosis matters, especially as researchers continue working to understand who is most at risk and why younger adults are being affected more often.