Association between KRAS mutation, detected in pancreatic cyst fluid, and long-term outcomes of patients.

BACKGROUND & AIMS: Endoscopic ultrasound (EUS) with fine-needle aspiration is routinely used to evaluate pancreatic cysts. We investigated the association between results from DNA analysis of cyst fluid and patient outcomes.
METHODS: In a retrospective analysis, we collected data from 113 patients with pancreatic cysts who underwent EUS with fine-needle aspiration at a tertiary care center from June 2004 to June 2007. Detailed follow-up data were obtained through October 2010 (mean, 47 months). Pancreatic cysts were categorized as nonbenign or benign on the basis of pathology analysis of surgical samples and patients' outcomes. We compared the patient characteristics, presenting symptoms, EUS imaging characteristics, and results from analysis of cyst fluid, including cytology results, levels of carcinoembryonic antigen, and DNA sequencing results.
RESULTS: Fifty-one patients underwent pancreatic surgery (10 had malignant, 18 had mucinous, and 16 had benign cysts), 63 patients were followed long-term, and 13 patients died of pancreatic cancer. On the basis of multivariate regression analysis, the presence of cyst solid component, patient symptoms, cyst size >3 cm, and detection of KRAS mutations at codons 12 and 13 in cyst fluid were independently associated with a nonbenign course.
CONCLUSIONS: KRAS mutations, detected in pancreatic cyst fluid, are associated with mucinous cysts and progression and development of malignancy and should be considered in assessing pancreatic cysts. The presence of a cyst solid component, patient symptoms, and cyst size greater than 3 cm were additional high-risk factors for a malignant course of disease.