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. The study was retrospective and involved matched groups derived from a comprehensive international health database. Researchers reported colorectal cancer in 0.7% of individuals who underwent an appendectomy, while the rate was 1.7% among patients who received only antibiotics. This difference translated into a 58% lower relative risk for the surgery group.
Utilizing data from the TriNetX Global Collaborative Network, researchers analyzed information from 168 healthcare organizations. They identified patients diagnosed with acute appendicitis who either received surgical removal or antibiotic therapy. After matching patients based on relevant characteristics, each group initially consisted of 15,774 individuals. The final analysis excluded those with prior colorectal cancer diagnoses, resulting in 15,616 patients who had an appendectomy and 15,295 who were treated with antibiotics. Researchers recorded 110 cases of colorectal cancer post-appendectomy and 254 cases in the antibiotic-only group.
The 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 research shows an association between treatment choice and later colorectal cancer diagnosis, it does not prove that removing the appendix prevents cancer.
Comparison of Surgical and Antibiotic Treatments
Acute appendicitis arises when the appendix becomes inflamed, a condition situated near the junction of the small and large intestines. Standard treatment often involves surgical removal of the organ, known as an appendectomy. In recent years, antibiotics have also become an accepted alternative for select patients. Valentine Nfonsam, a senior author and professor as well as executive vice chair of surgery at Morehouse School of Medicine, emphasized that antibiotic therapy remains a valuable option despite the new findings.
The investigation also explored factors influencing colorectal cancer development following appendicitis treatment. Sometimes, appendicitis occurs in individuals with an undiagnosed colorectal tumor. Tumors on the right side of the colon can obstruct the appendix, leading to inflammation. Surgery additionally provides tissue for pathological examination, which can detect abnormalities and prompt further diagnostic testing that is not typically performed immediately with antibiotic-only treatment.
Study Does Not Confirm Cancer Prevention
The appendix contains lymphoid tissue and plays a role in immune function within the digestive system. It is also linked to the gut microbiome, which includes bacteria and other microorganisms. The recent study did not determine whether these biological functions explain the observed differences in colorectal cancer diagnoses. It also did not establish whether inflammation or microbial shifts caused the association. Therefore, researchers refrain from suggesting that appendectomy acts as a preventive measure against colorectal cancer.
Previous studies have shown mixed results regarding the link 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 an appendectomy increases the long-term risk of colorectal cancer or precancerous conditions. The current study addresses a different question by comparing patients with appendicitis treated surgically to those receiving antibiotics alone. The authors noted that age, family history, and genetic factors remain key considerations when assessing colorectal cancer risk.