A rarely spoken about type of cancer is on the rise in younger generations. According to a new study, this rare cancer mainly affects those within the Gen X and Millennial generations. Compared to those born in the 1940s, the number of cases has tripled among Gen X’ers and quadrupled in Millennials. According to the researchers, numbers are on the rise because it is such a rare cancer and many people often mistake the symptoms for other common stomach issues. However, these symptoms are actually caused by appendix cancer, or appendiceal adenocarcinoma, which is characterized by the growth of a malignant tumor of the appendix lining.
The Study on the Rise of This Rare Cancer
For the 2025 study, the results of which were published in Annals of Internal Medicine, the researchers examined 4,858 cases in the United States recorded in the SEER cancer registries from 1975 to 2019. When compared to the 1945 cohort, they found a 3.41x higher incidence of appendix cancer in the 1980 cohort, and a 4.62x higher incidence in the 1985 cohort. This proved that there was clearly a higher risk of developing the rare cancer among members of the Gen X and Millennial generations. Unfortunately, a more precise analysis was not possible since the disease is so uncommon. The researchers, therefore, say that more data is needed to know how factors such as race affect the outcome.
However, even with this rise in cases, it remains a relatively rare cancer, with around 3,000 new cases reported in the United States annually. This is far less than other types of cancer, such as breast cancer. Yet, its rarity is also the reason so many clinicians and members of the public often overlook its symptoms. According to the authors of the study, “As incidence rates in younger generations are often indicative of future disease burden, these results support the need for histology-specific investigations of appendiceal adenocarcinoma, as well as increased education and awareness of appendiceal adenocarcinomas among health care providers and the public.”
Why It is Hard to Detect Appendix Cancer
The biggest issue when it comes to the adiagnosis of this rare cancer is that many people initially exhibit no symptoms. However, as the disease spreads, people begin to complain about issues such as abdominal pain and swelling, nausea, vomiting, changes in bowel movement, and feeling full quickly. Since these same symptoms are experienced in common problems such as irritable bowel syndrome, they are often overlooked or ignored. Another major issue is that, unlike other cancers, such as colon cancer, there is no routine screening test for this rare cancer. Most diagnoses happen by accident, like, for example, if someone gets an appendectomy and then a tumor is discovered in the process. Experts have warned that if a younger adult exhibits stomach issues that won’t go away, the doctor should consider appendix cancer as a potential cause and not just assume it is something harmless.
The Cause of this Rare Cancer
So, what are the risk factors that can lead to the development of appendix cancer? Well, because it is so rare, researchers are still unsure as to what causes it. However, they suspect that it could be a combination of lifestyle and environmental factors that impact the immune system and gut health. This is because similar patterns have been observed in other early-onset gastrointestinal cancers. Eating too many ultra-processed foods, for example, can impact the gut microbiome and mucosal barrier, which can lead to inflammation. Another trigger for inflammatory responses is the accumulation of microplastics in tissues. The gut is most likely a route for exposure, so researchers are currently examining whether long-term exposure to microplastics could possibly contribute to gastrointestinal cancers, including appendix cancer. Other potential lifestyle factors being considered are alcohol consumption, smoking, sedentary behavior, and obesity.
The Bottom Line
Appendiceal adenocarcinoma is considered a somewhat rare cancer. However, the generational rise in cases is a reason for concern and needs to be better understood. If you are a member of one of these generations and are experiencing certain symptoms that won’t go away, make sure that your health practitioner has considered appendix cancer. While practitioners are becoming more aware of the growing problem, the exact causes remain unknown. With more studies, they hope to gain more insight into what triggers this rare cancer and how to recognize and diagnose it sooner. However, as with many gastrointestinal cancers, the causes are likely a mixture of certain environmental and lifestyle factors. To lower your risk, make sure to refrain from consuming ultra-processed foods, in addition to smoking and alcohol. If you work at a desk, make sure to get regular exercise and not fall into a sedentary lifestyle.
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