Preoperative CA 19-9 and CEA as predictors of operative outcomes in resectable gastric cancer (GC).

Abstract

e15581 Background: We sought to investigate whether preoperative serum CA 19-9 and CEA levels are predictive of resectability, postoperative outcomes, and survival in resectable GC. Methods: The National Cancer Database (NCDB) was interrogated to identify resectable GC patients between 2004-2015. Gastric adenocarcinoma cases without M1 disease and who did or did not undergo definitive surgery were included. Pretreatment CA 19-9 and CEA levels were classified as high (≥98 U/mL) or low ( < 98 U/mL). Proportions of categorical variables were compared using the Chi-squared test (two-tailed). Hazard ratios (HRs) for overall survival (OS) were compared using multivariate Cox regression, adjusting for baseline demographic and clinical variables. Results: From 183,204 GC cases screened, a final 5,447 patients were available. Resection rates for patients with low (n = 1920) and high (n = 294) CA 19-9 were 69.2% and 40.8% (χ² 90.6, p < 0.00001). 69.6% were resectable with low CEA (n = 5044) and 35.1% were resectable with high CEA (n = 97, χ² 53.0, p < 0.00001). Mortality within 30 days of definitive surgery was 7.5% and 0% in those with high (n = 120) and low CA 19-9 (n = 1286, χ² 85.6, p < 0.00001). There was no significant difference between 30-day mortality across high and low CEA and between 30-day readmission rates across high and low CA 19-9 and CEA levels. Age, median income, high school graduation rate, Charlson comorbidity index, and AJCC clinical N stage all significantly correlated with OS in this cohort. Compared to low preoperative CA 19-9, high CA 19-9 was significantly associated with worse OS (HR 1.24, 95% confidence interval (CI) 1.13-1.37, p < 0.0001). Similarly, a high CEA correlated with worse OS compared to low CEA (HR 1.44, 95% CI 1.32-1.57, p < 0.0001). Conclusions: High preoperative CA 19-9 and CEA are associated wither lower resection rates and worse OS in resectable GC. CA 19-9 but not CEA level predicts for 30-day mortality. Prospective validation is warranted.