Background and objective: Five-year survival in pancreatic adenocarcinoma is less than 20%. While previous studies have postulated that a carbohydrate antigen 19-9 (CA19-9) threshold could predict outcome of resection, the role for CA19-9 in decision-making remains unclear. This study aims to assess whether CA19-9 levels combined with tumor size improve prediction of post-resection survival.
Method: A retrospective analysis was conducted on 109 patients with pancreatic adenocarcinoma who underwent perioperative chemotherapy followed by resection. The primary outcome of mortality was, divided into short (<1 year) or prolonged (>2 years). Univariate and multivariable analyses compared the tumor size-adjusted CA19-9 between the outcome groups.
Results: Twenty-seven (24.78%) and eighty-two (75.23%) patients were in the short survival and prolonged-survival groups, respectively. The mean CA19-9 was significantly greater in the short vs prolonged group (P < .001). Analyzing CA19-9 level by tumor size, the association of high CA19-9 and short survival was significant for small (≤2 cm) and large tumor (>4 cm), but not for intermediate-size tumors (2-4 cm). Adjusting for preoperative variable did not change this association.
Conclusion: CA 19-9 in combination with tumor size better identifies patients with prolonged post-resection survival. This prediction is most accurate in patients with either small (≤2 cms) or large (>4 cms) tumors compared to intermediate-size tumors.
Keywords: CA19-9; cancer survival; pancreatic cancer; tumor size.