CA 19-9 Surveillance Detects Recurrences Early and Contributes to Improvement in Survival in Resected Ampullary Cancers: Analysis of 572 Cases.

Abstract

To determine the clinical utility of serum carbohydrate antigen 19-9 (CA 19-9) surveillance for detecting recurrences in resected ampullary carcinomas (ACs). Although an established prognostic marker for pancreatic ductal adenocarcinoma, the value of CA 19-9 in resected ACs during follow-up is unknown. Retrospective analysis of ACs undergoing pancreaticoduodenectomy at Tata Memorial Centre-Mumbai, from January 2012 to January 2020 was performed. Survival, recurrence patterns, factors associated with recurrences, and the utility of CA 19-9 surveillance were assessed. The 5-year overall survival of 572 included patients with ACs was 56.4%. There were 251 (43.88%) recurrences, the majority being distant (n = 223). Higher "T" and "N" stages, margin involvement, perineural invasion, poor tumor differentiation, and pancreatobiliary subtype were associated with poor outcomes. The optimal CA 19-9 level to predict recurrence was 77.85 U/mL (sensitivity: 61.22%, specificity: 76.67%, area under the curve: 0.711); however, a serial rise was a more accurate predictor (sensitivity: 71.05%, specificity: 91.67%). The median duration between the first rise in CA 19-9 (>37 U/mL) and radiologic evidence of recurrence was 4.04 months. The optimal level of relative rise in CA 19-9 in diagnosing a recurrence was established at 2.79x (sensitivity: 46.26%, specificity: 83.33%, area under the curve: 0.614). A serial rise and absolute value of >200 U/mL was associated with recurrence in 87% and 92.9% of cases. Recurrence detection and treatment after serum CA 19-9 elevation was associated with a superior median survival as compared with recurrence detection without elevation (12.8 vs 7.6 months, P = 0.005). Serum CA 19-9 testing during follow-up evaluation detects recurrences early and improves survival in resected ACs, and, therefore, should be recommended as a routine surveillance test.