WASHINGTON, D.C. / RankWire.AI / – A recent study indicates that patients who had their appendix removed due to acute appendicitis are less likely to develop colorectal cancer later in life compared to those treated solely with antibiotics. The investigation was retrospective and analyzed matched cohorts from a comprehensive international health database. Researchers observed colorectal cancer in 0.7% of patients who underwent an appendectomy. In contrast, the rate was 1.7% among individuals who received only antibiotic therapy. This difference translated into a 58% lower relative risk for the group that had surgery.
The study utilized data from the TriNetX Global Collaborative Network, which compiles information from 168 healthcare organizations. Researchers identified patients diagnosed with acute appendicitis who either underwent surgery or received antibiotics. After matching patients based on relevant characteristics, each group comprised 15,774 individuals. The final analysis involved 15,616 patients who had an appendectomy and 15,295 who were treated with antibiotics alone, with earlier colorectal cancer diagnoses excluded. The data revealed 110 cases of colorectal cancer following appendectomy and 254 cases after antibiotic-only treatment.
These findings were presented at the American College of Surgeons Clinical Congress 2026, held in Washington from September 26 to September 29. The research abstract was reviewed and selected by the Scientific Forum program committee. However, no peer review has yet been conducted by a medical journal, which limits the definitive conclusions that can be drawn. The study demonstrates an association between the type of treatment for appendicitis and subsequent colorectal cancer diagnoses, but it does not prove that removing the appendix actively prevents cancer.
Comparison of Surgical and Antibiotic Approaches
Acute appendicitis results from inflammation of the appendix, a small organ situated near the junction of the small and large intestines. Traditionally, many cases are managed through surgical removal, known as an appendectomy. In recent years, antibiotics have gained acceptance as an alternative treatment for select 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 findings of this study.
The researchers also investigated factors that might influence how colorectal cancer develops after treating appendicitis. Sometimes, appendicitis occurs in individuals with an undiagnosed colorectal tumor. A tumor located on the right side of the colon can block the appendix, causing inflammation. Surgery offers the benefit of providing tissue for pathological examination, which can identify abnormalities and prompt additional diagnostic testing that may not be immediately performed with antibiotic-only treatment.
Limitations and Future Considerations
The appendix plays a role in immune function, containing lymphoid tissue and participating in gut microbiome interactions, which include bacteria and other microorganisms in the digestive system. The current study did not clarify whether these biological functions account for the observed difference in colorectal cancer diagnoses or whether inflammation or microbial shifts are causal factors. As a result, researchers refrained from suggesting that appendectomy should be used as a method of cancer prevention.
Previous research has shown mixed results regarding the link between appendectomy and colorectal cancer. A 2024 prospective study tracked over 224,000 participants across three large cohorts for up to 32 years, finding no evidence that appendectomy increases the long-term risk of colorectal cancer or precursors. The new research, however, addresses a different question by comparing patients with appendicitis treated surgically to similar patients who received antibiotics alone. The authors noted that factors such as age, family history, and genetic predisposition remain significant when evaluating colorectal cancer risk.