Cancer embryonic antigen (CEA) levels in patients with appendiceal adenocarcinoma predict response to neo-adjuvant chemotherapy and overall survival

Background and Objectives: Serum tumor markers are widely used for diagnosis, prognosis, treatment response, and surveillance. Our study evaluated cancer embryonic antigen (CEA) in patients with appendiceal adenocarcinoma. Methods: The National Cancer Database was reviewed (2004–2011) for patients with surgical treatment for appendiceal adenocarcinoma. Patients were stratified into two groups: normal and elevated CEA. Multivariable adjusted Cox proportional hazards regression analyses were used to determine the independent effect of CEA on survival. Results: Our study consisted of 2867 patients, 54.0% having elevated CEA. Patients with elevated CEA were more likely to have Stage IV disease, be female, and African American; all p < 0.001. Three-year overall survival (OS) was significantly higher with normal CEA (75.5% vs. 62.8%, p < 0.001). On multivariable analysis, elevated CEA was associated with worse survival (hazard ratio 1.49, 95% confidence interval 1.23–1.80). Patients with elevated CEA had improved 3-year OS with neo-adjuvant compared to adjuvant chemotherapy (p = 0.004), while those with normal CEA showed no difference. Conclusions: In patients with surgically treated appendiceal adenocarcinoma, preoperative elevation in CEA independently predicts decreased 3-year survival and correlates with improved OS with neo-adjuvant therapy. CEA levels should be considered in clinical decision-making regarding neo-adjuvant therapy in patients with appendiceal adenocarcinoma.