Association between Appendectomy and Subsequent Colorectal Cancer Development: An Asian Population Study

Abstract

ObjectivesThe appendix may modulate colon microbiota and bowel inflammation. We investigated whether appendectomy alters colorectal cancer risk.MethodsWe identified a cohort of 75979 patients who underwent appendectomy between 1997 and 1999 based on the insurance claims of Taiwan. A comparison cohort of 303640 persons without appendectomy was selected randomly, frequency matched by age, sex, comorbidity and entry year was also selected. We monitored subsequent colorectal cancer development in both cohorts.ResultsThe overall colorectal cancer incidence was 14% higher in the appendectomy patients than in the comparison cohort (p <0.05): the highest incidence was observed for rectal cancer, and the lowest incidence was observed for cancer of the cecum-ascending colon for both cohorts. Men were at higher risk than women. Subjects ≥ 60 years had an HR of 12.8 compared to those <60 years. The incidence of colorectal cancer was much higher in 1.5-3.5 years post appendectomy follow-up than for the comparisons (HR of 2.13). Patients who received an incidental appendectomy had an HR of 2.90 when compared to the comparisons.ConclusionsResults of our study suggest that appendectomy in patients with appendicitis is likely associated with the development of colorectal cancer in the post-surgery period.

Non-operative management of appendicitis in children

“…By removal of the appendix, however, we are removing an immune organ and potentially a reservoir of beneficial microbiota. This may predispose to subsequent development of other pathologies, such as recurrent Clostridium difficile infection,52 Crohn’s disease53 and colorectal cancer,54 although this is a controversial area and it is difficult to dissect appendicitis from appendectomy and to control for diagnostic uncertainty.…”

Appendicitis before Age 20 Years Is Associated with an Increased Risk of Later Prostate Cancer

“…Previous studies examining the association between appendicitis or appendectomy and risk for neoplastic disease have reported contradictory results (19)(20)(21)(22). To our knowledge only two previous studies have addressed the association between appendicitis or appendectomy and prostate cancer risk, none of which reported a significant association.…”

Peer Review #1 of "Increased chronic kidney disease development and progression in diabetic patients after appendectomy: a population-based cohort study (v0.1)"

“…17 The microbiota in the large bowel can change after appendectomy, leading to dysbiosis. 9 Gut dysbiosis and inflammation are underlying and linking factors between CKD and DM. 18 Appendectomy could worsen pre-existing dysbiosis in diabetic patients, increasing the risk of ESRD development.…”

“…6 Furthermore, studies have shown that appendectomy-related impairment of the microbiota may lead to dysbiosis and induce various diseases, including ulcerative colitis, Crohn's disease, Clostridium difficile infection, colorectal cancer, rheumatoid arthritis, and cardiovascular disease. [6][7][8][9] To date, there is no evidence confirming that appendectomy contributes to CKD. In this study, we evaluated the correlation between prior appendectomy and the occurrence of CKD and ESRD.…”