Ratio of CA19-9 level to total bilirubin as a novel prognostic indicator in patients with pancreatic head carcinoma following curative resection

Background Ratio of carbohydrate antigen 19-9 level to total bilirubin (CA19-9/TB) is used to reduce the influence of obstructive jaundice on the concentration of CA19-9, thereby determining the correlation between CA19-9/TB and tumor recurrence or long-term prognosis of patients with pancreatic head cancer (PHC). Methods In this study, a total of 339 patients were enrolled. The optimal cut-off value of CA19-9/TB was determined by ROC curve based on preoperative CA19-9/TB and 1-year survival, and the patients were divided into low-ratio group (Group 1) and high-ratio group (Group 2) accordingly. Univariate and multivariate analyses were performed to screen out the risk factors affecting postoperative recurrence and long-term prognosis of PHC. Results The best cut-off value of CA19-9/TB was 7.7. [area under curve (AUC), 0.599, 95% CI: 0.533-0.666] Compared with Group 1, Group 2 had lower CA19-9, higher TB and lymph node metastasis rate (P<0.05). The 1-, 2- and 3-year disease-free survival (DFS) rates of patients in Group 1 and Group 2 were 70.1%, 44.3% and 30.8%, 39.9%, 17.1% and 13.6%, respectively (P=0.000), and the 1-, 2- and 3-year overall survival (OS) rates were 81.5%, 52.1% and 31.5%, 53.7%, 20.5% and 14.2%, respectively (P=0.000). Multivariate analysis showed that CA19-9/TB, portal vein invasion and lymph node metastasis were independent risk factors for postoperative tumor recurrence and long-term survival of PHC. Conclusions Compared with CA19-9 alone, CA19-9/TB is more valuable in judging postoperative tumor recurrence and long-term survival of PHC. The lower the ratio, the better the long-term prognosis.