Abstract:
AIM: Appendicitis in older adults may present as the first sign of underlying colorectal cancer. We aim to determine whether there was a difference in the rate of diagnosis of colorectal carcinoma for patients ≥45 years following a presentation with appendicitis, compared with New Zealand standardised rates. METHOD: Retrospective study of patients ≥45 years with a confirmed diagnosis of appendicitis from 2003 to 2015 inclusive. The rate of colorectal carcinoma diagnosed during the 36-month follow-up period was calculated and compared to standardised rates, as per the New Zealand cancer registry. RESULTS: Six hundred and twenty-nine patients were included for analysis, 15 had a diagnosis of colorectal cancer in the follow-up period. Patients ≥45 years had a 6.3-fold (CI 3.6-10.2) increased risk of colorectal carcinoma than predicted given the population demographics. Those patients aged between 45-60 years had a 17-fold (95% CI 8-32.2) increased standardised risk ratio. CONCLUSION: This is the first study of its kind conducted in Australasia. This study found patients ≥45 years who present with appendicitis have significantly increased risk of underlying colorectal cancer. Until further research is conducted the authors recommend clinicians consider colonic investigation for older adults following a diagnosis of appendicitis.