Removing inflamed appendix may lower colorectal cancer risk
Study of 30,000+ appendicitis cases finds appendectomy linked to 58% lower colorectal cancer risk than antibiotics, highlighting potential long-term oncologic considerations and monitoring
Patients who had surgery for an inflamed appendix had a significantly lower risk of developing colorectal cancer than those treated with antibiotics, according to an analysis of more than 30,000 cases.
Surgery was once the standard of care for acute appendicitis. Management of the condition "has changed significantly over the last decade, and antibiotic therapy is now an accepted option," study leader Dr. Valentine Nfonsam of Morehouse School of Medicine in Atlanta explained in a statement.
Previous comparisons of the two approaches have focused on short-term outcomes.
In the study, Nfonsam and colleagues reviewed data on 15,774 patients diagnosed with acute appendicitis who underwent appendectomy and another 15,295 who were treated with antibiotics alone.
In the ensuing years, colorectal cancer was diagnosed in 0.7% of the appendectomy group and in 1.7% of the antibiotics group, according to results reported at the American College of Surgeons Clinical Congress in Washington.
After accounting for individual risk factors, appendectomy was associated with a 58% lower relative risk of a subsequent colorectal cancer diagnosis.
The appendix was once thought to be useless, but emerging research suggests that is not true, Nfonsam said.
Instead, it may play a role in the intestinal immune system and the gut microbiome, the community of microorganisms living in the digestive tract.
Whether persistent inflammation or changes in the gut microbiome contribute to development of cancer is biologically plausible, but the study wasn't designed to answer that question, Nfonsam said.
"These results should not be interpreted to mean that everyone with appendicitis needs an appendectomy to prevent cancer," he said.
"Antibiotic management remains an important option. But when we discuss non-operative management, we should also think beyond the immediate episode of appendicitis and consider potential long-term oncologic risk and appropriate monitoring."