WASHINGTON, D.C. / RankWire.AI / – According to recent findings, patients who had their appendix removed due to acute appendicitis exhibited a lower incidence of later colorectal cancer diagnoses compared to those who were treated solely with antibiotics. This retrospective investigation analyzed matched groups extracted from a comprehensive international health database. Researchers observed colorectal cancer in 0.7% of individuals who underwent an appendectomy, whereas the rate was 1.7% among patients treated only with antibiotics. This difference indicates a 58% reduction in relative risk within the surgical group.
Utilizing the TriNetX Global Collaborative Network, which aggregates data from 168 healthcare organizations, researchers identified patients diagnosed with acute appendicitis who received either surgical intervention or antibiotic therapy. After matching patients based on relevant characteristics, each initial cohort comprised 15,774 individuals. The final analysis involved 15,616 patients who had appendectomies and 15,295 who received antibiotics alone, following the exclusion of those with prior colorectal cancer diagnoses. The data revealed 110 cases of colorectal cancer following appendectomy compared to 254 cases in the antibiotic-only group.
These results 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, the study has not yet undergone peer review by a medical journal. This limits the ability to draw definitive conclusions, as the study only shows an association between the type of treatment and subsequent colorectal cancer diagnosis, without establishing that appendix removal directly prevents the disease.
Comparison of surgical and antibiotic treatments for appendicitis
Acute appendicitis results from inflammation of the appendix, which is situated near the junction of the small and large intestines. Traditionally, many cases are managed by surgically removing the organ, known as an appendectomy. More recently, antibiotics have become a recognized alternative treatment for selected patients. Valentine Nfonsam, a professor and executive vice chair of surgery at Morehouse School of Medicine, emphasized that despite the findings, antibiotic treatment remains a vital option.
The research also explored potential factors influencing the development of colorectal cancer after appendicitis treatment. It is possible for patients to have an undiagnosed colorectal tumor that manifests as appendicitis, particularly when a tumor on the right side of the colon obstructs the appendix, causing inflammation. Additionally, surgery allows clinicians to obtain tissue for pathological examination, which can detect abnormalities and prompt further diagnostics that are not typically performed immediately in antibiotic-only cases.
Study does not confirm cancer prevention capabilities
The appendix contains lymphoid tissue and is involved in immune responses within the gut, with recent research also linking it to the gut microbiome, comprising bacteria and other microorganisms. However, the current study did not clarify whether these biological functions account for the observed differences in colorectal cancer diagnoses or whether inflammation or microbial alterations are causative factors. Consequently, the authors refrained from suggesting that appendectomy serves as a method of cancer prevention.
Previous research has yielded mixed results regarding the relationship between appendectomy and colorectal cancer. For instance, a 2024 prospective analysis tracked over 224,000 participants across three large cohorts for up to 32 years, finding no evidence that appendectomy increased long-term risk of colorectal cancer or precursors. This new study, however, addresses a different question by comparing patients with appendicitis who underwent surgery to those treated with antibiotics alone. Researchers highlighted that factors such as age, family history, and genetic predisposition continue to be significant when evaluating colorectal cancer risk.