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

ABSTRACT

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.