LAUSR

Background/Aim: The proportion of patients with liver metastases in patients with appendiceal versus colorectal adenocarcinomas was 3.1 percent and 24 percent, respectively, in our peritonectomy centre. From our internal analyses, carcinoembryonic antigen (CEA) was potentially involved. A hypothesis was proposed regarding the natural progression of appendiceal adenocarcinoma. To support this, a systematic review and meta-analysis were performed to examine whether there was a difference in the proportion of patients with an elevated CEA in appendiceal versus colorectal adenocarcinoma patients in the current literature. Materials and Methods: Medline (PubMed), EMBASE (Ovid), Cochrane Central Register of Controlled Trials (CENTRAL), Cumulative Index to Nursing and Allied Health Literature, Clinicaltrials.gov, Web of Science, and Google Scholar were searched. All studies involving patients with appendiceal and/or colorectal adenocarcinoma were eligible. Data were analysed by grouping appendiceal and colorectal adenocarcinoma in separate meta-analyses, and then comparing their weighted proportions of elevated CEA. Principal summary measures were weighted proportions of patients with elevated CEA. Results: From the initial identification of 1,928 articles, 136 articles were included in the final synthesis. Ninety-two articles were included in the meta-analysis. Proportions of appendiceal and colorectal adenocarcinoma with elevated CEA were 56% (95%CI=47-65%) and 42% (95%CI=38-46%), respectively (p=0.0001). Conclusion: Patients with appendiceal adenocarcinoma had a higher proportion of CEA than those with colorectal adenocarcinoma. Future studies should focus on the several aspects of CEA presented in patients with appendiceal adenocarcinoma. This could provide treatments for patients with colorectal adenocarcinoma by preventing the development of liver metastases.