Serum carbohydrate antigen 19-9 greater than 100 and risk of invasive carcinoma in pancreatic intraductal papillary mucinous neoplasms: Worrisome feature or high-risk stigmata?

BACKGROUND

Elevated serum carbohydrate antigen 19-9 was incorporated as a worrisome feature in the International Association of Pancreatology 2017 Fukuoka guidelines and is associated with an increased risk of invasive carcinoma. We compared the independent predictive value of carbohydrate antigen 19-9 >100 U/mL with other worrisome feature and high-risk stigmata to better delineate its utility and importance.

METHODS

We conducted a retrospective analysis of all patients who underwent pancreatic resection for intraductal papillary mucinous neoplasms at a high-volume tertiary center in the United States. Clinicopathologic and radiologic variables were compared by the final pathologic status. Multivariable logistic regression was used to adjust for worrisome feature and high-risk stigmata.

RESULTS

Of 645 patients who underwent pancreatectomy, 49% had low-grade dysplasia, 23% had high-grade dysplasia, and 28% had invasive carcinoma. A greater proportion of patients with invasive carcinoma had serum carbohydrate antigen 19-9 levels >100 U/mL (30% vs 5% vs 4%, P < .001). Multivariable analysis revealed that serum carbohydrate antigen 19-9 >100 U/mL (odds ratio, 7.24, P < .001), jaundice (odds ratio, 6.04, P < .001), main pancreatic duct diameter >10 mm (odds ratio, 4.05, P < .001), and mural nodules >5 mm (odds ratio, 3.12, P < .001) were significant predictors of invasive carcinoma. Serum carbohydrate antigen 19-9 was not predictive of high-grade dysplasia.

CONCLUSION

Serum carbohydrate antigen 19-9 >100 U/mL performed more similarly to other high-risk stigmata and appeared to be the strongest predictor of invasive carcinoma. Serum carbohydrate antigen 19-9 >100 U/mL is a concerning finding that warrants consideration of surgical resection.