WASHINGTON, D.C. / RankWire.AI / – According to recent findings, patients who had their appendix removed due to acute appendicitis showed a lower incidence of subsequent colorectal cancer compared to those treated solely with antibiotics. This retrospective analysis utilized data from a sizable international health database. Researchers observed colorectal cancer in 0.7% of individuals who underwent an appendectomy, whereas the rate was 1.7% among those who received only antibiotics. This difference indicated a 58% decrease in relative risk for the surgery group.
The study employed data from the TriNetX Global Collaborative Network, which includes information from 168 healthcare organizations. Patients diagnosed with acute appendicitis were identified and classified based on whether they received surgical or antibiotic treatment. After matching participants based on relevant characteristics, each group initially comprised 15,774 individuals. Following the exclusion of early colorectal cancer cases, the final analysis involved 15,616 patients who had an appendectomy and 15,295 who were treated with antibiotics only. Researchers recorded 110 colorectal cancer cases following appendectomy and 254 cases after antibiotic treatment.
These findings were presented at the American College of Surgeons Clinical Congress 2026, held in Washington from Sept. 26 through Sept. 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 study shows an association between treatment method and subsequent colorectal cancer diagnosis, it does not prove that removing the appendix prevents the development of colorectal cancer.
Comparison of Surgical and Antibiotic Treatments
Acute appendicitis involves inflammation of the appendix, a small organ positioned near the junction of the small and large intestines. Traditionally, many cases are managed through surgical removal, known as an appendectomy. Recently, antibiotics have also become an accepted alternative, especially for selected patients. Valentine Nfonsam, a professor and executive vice chair of surgery at Morehouse School of Medicine, emphasized that antibiotic therapy remains an important option despite the findings of this study.
The researchers also explored factors that might influence how colorectal cancer manifests after appendicitis treatment. Sometimes, an undiagnosed colorectal tumor can cause appendicitis, especially if a tumor on the right side of the colon obstructs the appendix and triggers inflammation. Surgery allows clinicians to obtain tissue samples for pathological examination, which can reveal abnormalities and prompt further testing that is not typically performed with antibiotic-only management.
Study Does Not Confirm Cancer Prevention Benefits
The appendix contains lymphoid tissue and plays a role in immune function within the gut. It has also been linked to the gut microbiome, which includes bacteria and other microorganisms in the digestive system. The current study did not clarify whether these biological functions influence the observed differences in colorectal cancer diagnoses. It also did not determine whether inflammation or changes in microbial communities are responsible for the association. Therefore, researchers stopped short of suggesting that appendectomy acts as a preventive measure against colorectal cancer.
Previous studies have shown mixed results regarding the relationship between appendectomy and colorectal cancer. A 2024 prospective analysis tracked over 224,000 participants across three large cohorts for up to 32 years. That research found no evidence that appendectomy increased long-term colorectal cancer risk or precancerous conditions. The new study, however, focuses on comparing patients with acute appendicitis treated surgically versus those managed with antibiotics alone. Researchers noted that age, family history, and genetic predisposition remain significant factors in assessing colorectal cancer risk.