A new study finding a rise in appendix cancer cases in people younger than 50 comes as no surprise to University of Colorado Cancer Center member Steven Ahrendt, MD, who throughout his career as a surgical oncologist has regularly treated the cancer in people in their teens and 20s.
“I can remember operating on people in their late teens when I was just starting out in practice, and just in the past couple of weeks, I have treated a 21-year-old and a 19-year-old,” he says. “Their cases are a little bit different than what this paper is referring to — the paper talks about adenocarcinomas, and we see a fair number of neuroendocrine cancers in young patients — but I certainly see patients in their 20s and 30s who have advanced appendix tumors that we take care of.”
The colorectal connection
The new research from the Vanderbilt University Medical Center finds that 1 in every 3 appendix cancers is diagnosed in adults younger than 50, similar to the rise in colorectal cancer rates among young adults that caused the U.S. Preventive Services Task Force in 2021 to lower the recommended screening age for colorectal cancer to 45 from 50.
“Colon cancer, anatomically, is very similar to appendix cancer,” says Ahrendt, professor of surgical oncology in the CU Department of Surgery. “The appendix is a small vestigial organ that hangs off the colon, and there are tumors that are unique to the appendix — a few of those were included in this study. But we know that colon cancer has been increasing in incidence in young adults, so it stands to reason that the same factors are operating in patients with appendix cancer.”
Ahrendt says it is important to note that despite its increased numbers in young adults, appendix cancer is much more rare than colorectal cancer — around 3,000 new cases per year in the U.S., as opposed 150,000 new cases of colorectal cancer.
Causes and treatment
Cancer experts don’t fully understand the cause of the rise of colorectal and appendix cancer, but Ahrendt says he has heard many environmental factors mentioned as possible reasons younger people are getting diagnosed with gastrointestinal cancers.
“There's a whole list of things that have been suggested for colon cancer, including processed foods and food additives,” he says. “Generally, the diet has shifted from what people were eating 50 years ago. The activities have shifted. People are eating more. They're eating more processed food. Obesity is much more rampant now than it was 50 years ago.”
Early-stage appendix cancers often present with acute appendicitis, and the diagnosis is an unpleasant surprise several days later in the pathology report. If the cancer hasn’t spread to other areas of the body, patients benefit from an additional surgery called a right hemicolectomy, which removes the part of the small and large intestines and regional lymph nodes. At times the cancer can be difficult to diagnose, Ahrendt says — occasionally it may visible on a colonoscopy, but usually is not; sometimes it is noticed incidentally on a CAT scan for another issue. Other warning signs include worsening abdominal pain and weight loss as the cancer starts to obstruct the intestine, or a distended abdomen due to the large volume of tumor the cancer can create.
“Some patients barely notice that their abdomen is getting more and more distended, because it can be such a slow process,” he says. “I've had patients who think they're getting older and out of shape, and that's why their abdomen is growing.”
