Association between appendectomy and subsequent colorectal cancer development: an Asian population study

PLoS One. 2015 Feb 24;10(2):e0118411. doi: 10.1371/journal.pone.0118411. eCollection 2015.

Abstract

Objectives: The appendix may modulate colon microbiota and bowel inflammation. We investigated whether appendectomy alters colorectal cancer risk.

Methods: We identified a cohort of 75,979 patients who underwent appendectomy between 1997 and 1999 based on the insurance claims of Taiwan. A comparison cohort of 303,640 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.

Results: The 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.

Conclusions: Results of our study suggest that appendectomy in patients with appendicitis is likely associated with the development of colorectal cancer in the post-surgery period.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Appendectomy
  • Appendicitis / surgery*
  • Asian People
  • Cohort Studies
  • Colorectal Neoplasms / epidemiology
  • Colorectal Neoplasms / etiology*
  • Demography
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Proportional Hazards Models
  • Risk Factors
  • Sex Factors
  • Taiwan / epidemiology

Grants and funding

The study was supported by Taiwan Department of Health Clinical Trial and Research Center of Excellence (DOH 100-TD-B-111-004) and Cancer Research Center for Excellence (DOH102-TD-C-111-005), Taiwan Ministry of Health and Welfare Clinical Trial and Research Center of Excellence (MOHW103-TDU-B-212-113002), China Medical University Hospital (grant number 1MS1), and the National Sciences Council, Executive Yuan (grant number NSC 100-2621-M-039-001). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.