WASHINGTON, D.C. / RankWire.AI / – According to recent research, patients who had their appendix removed due to acute appendicitis experienced fewer subsequent diagnoses of colorectal cancer compared to those treated solely with antibiotics. The retrospective analysis utilized a large international health database to compare matched groups. 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 translated into a 58% lower relative risk for the surgery group.
Data was sourced from the TriNetX Global Collaborative Network, encompassing information from 168 healthcare organizations. Patients diagnosed with acute appendicitis who were treated either surgically or with antibiotics were identified. After matching participants based on relevant factors, each group initially included 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 received only antibiotics. Among these, 110 cases of colorectal cancer developed after appendectomy, compared to 254 cases in the antibiotic-only group.
The 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. Nevertheless, no peer review by a medical journal has yet been conducted, which limits the strength of the conclusions. While the study demonstrates an association between treatment type and later colorectal cancer diagnosis, it does not prove that appendectomy prevents the disease.
Comparison of Surgical and Antibiotic Approaches in Treatment
Acute appendicitis involves inflammation of the appendix, a small organ near the junction of the small and large intestines. Traditionally, the standard treatment has been surgical removal, known as an appendectomy. However, antibiotics are now also accepted as a treatment option for selected cases. 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 research team also explored factors influencing the potential development of colorectal cancer post-appendicitis. In some cases, appendicitis occurs in individuals with an undiagnosed colorectal tumor, especially when a tumor on the right side of the colon obstructs the appendix, causing inflammation. Surgery offers tissue for pathological examination, which can reveal abnormalities and prompt further diagnostic testing that might not be performed immediately when antibiotics are used alone.
Limitations in Establishing Cancer Prevention
The appendix plays a role in immune function, containing lymphoid tissue, and has been linked to the gut microbiome, which includes bacteria and other microorganisms within the digestive system. The current study did not determine whether these biological functions explain the observed differences in colorectal cancer diagnoses nor whether inflammation or microbial alterations are causal factors. Consequently, researchers stopped short of suggesting that appendectomy acts as a form of cancer prevention.
Previous studies have shown mixed results regarding the connection between appendectomy and colorectal cancer. For instance, a 2024 prospective analysis followed over 224,000 participants across three large cohorts for up to 32 years, finding no evidence that appendectomy increases long-term colorectal cancer risk or precancerous conditions. This new study, however, focuses on comparing patients with acute appendicitis treated surgically to those receiving antibiotics alone. Researchers noted that age, family history, and genetic predisposition remain key factors when evaluating colorectal cancer risk.