Association between high initial CEA, CA 19-9 levels and HER-2 status and their prognostic values on overall survival in metastatic gastric cancer

Abstract

Purpose: This study aimed to investigate the correlations between baseline levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9) and immunohistochemical (IHC), Human epidermal growth factor receptor (HER-2) expressions; and question their prognostic values in patients with metastatic gastric cancer. Methods: Gastric cancer patients were retrospectively analyzed. Demographic information, clinical stages, immunohistochemical HER-2 expressions and serum CEA, serum CA 19-9 levels were evaluated at the time of diagnosis. The correlations between HER-2 IHC expressions and the initial marker levels were assessed, and survival analyses were performed. Results: A total of 411 patients were included in the study. Median age of patients was 58 years (range: 22-90); males: 297 (72.3%); females: 114 (27.7%). Median overall survival (OS) was 24 months (range: 19-29). Patient HER-2 IHC expression 0, 1, 2, 3 ratios were 43, 22, 16, and 19%, respectively. At the time of diagnosis, the median value of CEA was 4 (range: 3-5), and the median value of CA 19-9 was 18 (range: 14-22). The increase in CEA and CA 19-9 levels were correlated with the increase of IHC levels (p=0.0001). OS of patients with high initial CEA levels (>5 ng/mL) were significantly shorter than those with low initial CEA levels (<5 ng/mL). Conclusion: Significant positive correlations were shown between HER-2 IHC expressions and CEA, CA 19-9 levels. Baseline CEA, CA 19-9 levels predicted HER-2 positivity and this directly affected treatment and OS.