WASHINGTON, D.C. / RankWire.AI / – According to recent research, patients who had their appendix removed due to acute appendicitis experienced fewer later diagnoses of colorectal cancer compared to those treated solely with antibiotics. The study was retrospective and utilized data from a large international health database to compare matched groups. Researchers observed a colorectal cancer occurrence of 0.7% among patients who underwent an appendectomy, whereas the rate was 1.7% in those who only received antibiotics. This difference translated into a 58% lower relative risk for the surgery group.
Data was gathered from the TriNetX Global Collaborative Network, which encompasses information from 168 healthcare organizations. Patients diagnosed with acute appendicitis were identified and classified based on whether they received surgical removal or antibiotic therapy. After matching for relevant characteristics, each group initially included 15,774 individuals. The final analysis comprised 15,616 patients who had an appendectomy and 15,295 who received antibiotics only, following the exclusion of early colorectal cancer cases. The records revealed 110 instances of colorectal cancer following appendectomy, compared to 254 cases among those treated solely with antibiotics.
These findings were presented at the American College of Surgeons Clinical Congress 2026, hosted in Washington from September 26 to September 29. The research abstract was reviewed and selected by the Scientific Forum program committee. However, the study has not yet undergone peer review by a medical journal, which limits the strength of the conclusions. While the research indicates an association between treatment type and subsequent colorectal cancer diagnosis, it does not prove that removing the appendix prevents the disease.
Comparison of Surgical and Antibiotic Approaches
Acute appendicitis, characterized by inflammation of the appendix, occurs near the junction of the small and large intestines. Traditionally, many cases are managed with surgical removal, known as appendectomy, but antibiotics have become an accepted alternative for selected patients. Senior author Valentine Nfonsam, a professor and executive vice chair of surgery at Morehouse School of Medicine, emphasized that antibiotic therapy remains a vital option despite the new findings.
The study also investigated factors that might influence the development of colorectal cancer after appendicitis treatment. It is possible for an undiagnosed colorectal tumor to cause appendicitis, especially if a tumor on the right side of the colon obstructs the appendix, leading to inflammation. Surgery provides tissue for pathological examination, which can reveal abnormalities and prompt further diagnostic testing that may not be immediately performed with antibiotics alone.
Study Does Not Confirm Cancer Prevention
The appendix plays a role in immune function due to its lymphoid tissue and has been linked to the gut microbiome, which includes bacteria and other microorganisms in the digestive system. The recent research did not clarify whether these biological roles explain the variation in colorectal cancer diagnoses or whether inflammation or microbial shifts caused the observed association. Consequently, researchers stopped short of claiming that appendectomy serves as a cancer prevention strategy.
Previous studies have yielded mixed results regarding the relationship between appendectomy and colorectal cancer. For instance, a 2024 prospective study tracked over 224,000 participants across three large cohorts for up to 32 years and found no evidence that appendectomy increased long-term colorectal cancer risk or precursors. The current study addresses a different question, comparing surgical treatment for appendicitis with antibiotic therapy in similar patient groups. Researchers note that age, family history, and genetic factors remain established considerations in assessing colorectal cancer risk.