Risk of colorectal cancer in patients with appendicitis over the age of 40 years

Colorectal screening following appendectomy in adult patients: a systematic review

PURPOSE

Although the association between appendicitis and colorectal cancer in older patients has received attention, postoperative colorectal screening through endoscopy is not currently recommended. This study conducted a systematic review of the literature on colorectal screening following appendectomy in adult patients.

METHODS

A literature search was performed using online databases. Studies reporting colorectal surveillance after appendectomy in adult patients were retrieved for assessment.

RESULTS

Eight articles including a total of 3,995 patients were published between 2013 and 2023. An age of 40 years was the lower threshold in 6 of the 8 articles. Postoperative colorectal screening occurred in 771 patients (19.3%). Endoscopy was performed in 95.2% of cases and computed tomography-colonography in 4.8%. During endoscopic examinations, a lesion was discovered in 184 of 771 patients (24.0%), and an adenomatous polyp was found in 154 of 686 patients (22.5%). The overall cancer rate was 3.9% (30 of 771 patients). The tumor was located in the right-sided colon in 46.7% of the patients, in the cecum in 20.0%, in the rectum in 16.7%, in the left-sided colon in 10.0%, and in the sigmoid colon in 6.7%.

CONCLUSION

Performing post-appendectomy colorectal screening in patients >40 years of age could allow early detection of an underlying lesion.

Appendectomy and appendicitis do not increase colorectal cancer risk: evidence from Mendelian randomization

Background

Acute appendicitis (AA) is one of the most prevalent acute abdominal diseases and appendectomy is the definitive treatment of appendicitis. However, whether appendicitis and appendectomy cause colorectal cancer (CRC) is controversial. The results of observational studies are contradictory, but randomized controlled trials (RCT) cannot be conducted.

Methods

Data of appendectomy, AA, and CRC were obtained from the IEU Open GWAS project. We selected several Genome-wide association studies (GWAS) summary statistics for CRC: statistics for colon cancer (CC) were obtained from MRC-IEU and Neale lab, respectively; statistics for rectum cancer (RC) were obtained from MRC-IEU and FinnGen, respectively; statistics for CRC were provided by Sakaue S et al. Mendelian randomization (MR) was used to evaluate the causal relationships between exposure and outcomes. Inverse variance weighting (IVW) was the most important analysis method. Meta-analysis was used to summarize the results of IVW to increase the reliability and sensitivity analysis was used to evaluate the robustness of the results.

Results

According to the results of IVW, appendectomy did not increase risk of CC: MRC-IEU (OR:1.009, 95%CI:0.984-1.035, P=0.494), Neale lab (OR:1.016, 95%CI:0.993-1.040, P=0.174); Appendectomy also did not increase risk of RC: MRC-IEU(OR:0.994, 95%CI:0.974-1.014, P=0.538), FinnGen(OR:2.791, 95%CI:0.013-580.763, P=0.706); Appendectomy also did not increase risk of CRC: Sakaue S(OR:1.382, 95%CI:0.301-6.352, P=0.678). Appendicitis did not increase risk of CC: MRC-IEU(OR:1.000, 95%CI:0.999-1.001, P=0.641), Neale lab(OR:1.000, 95%CI:1.000-1.001, P=0.319); Appendicitis also did not increase risk of RC: MRC-IEU(OR:1.000, 95%CI:0.999-1.000, P=0.361), FinnGen(OR:0.903, 95%CI:0.737-1.105, P=0.321); Appendicitis also did not increase risk of CRC: Sakaue S (OR:1.018, 95%CI:0.950-1.091, P=0.609). The results of Meta-analysis also showed appendectomy (P=0.459) and appendicitis (P=0.999) did not increase the risk of CRC.

Conclusions

Appendectomy and appendicitis do not increase the risk of colorectal cancer. More clinical trials are needed in the future to verify the causal relationships.

Perforated appendicitis with endosalpingiosis

Endosalpingiosis a condition of ectopic glandular epithelium diagnosed histologically, most commonly on pelvic and abdominal peritoneum, that can be associated with abdominal pain mimicking appendicitis. There is evidence emerging that endosalpingiosis may be associated with serous ovarian malignancies. Here we describe a case of perforated appendicitis with concurrent endosalpingiosis. Further research is required to better elucidate the association between endosalpingiosis and malignancy, and the implications of a concurrent presentation with a hollow viscus perforation.