Cyst Fluid Cea Concentration, Age and a Diagnosis of Malignancy Are Associated with Increased Mortality: An Update From the Cooperative Pancreatic Cyst (CPS) Study

Abstract

The natural history of mucinous cystic lesions is unknown. Mucinous cystic neoplasms (MCN) and intraductal papillary mucinous neoplasms (IPMN) are pre-malignant or malignant lesions that may be associated with a greater mortality rate compared to non-mucinous lesions. We have monitored the outcome of patients in the CPC study to identify risk factors for mortality. Methods: Clinical testing results and patient outcome were prospectively collected in the CPC Study from May 1, 1999 to November 19, 2004. We hypothesized that mortality rate would be determined by type of cystic lesion, presence of malignancy, and cyst fluid CEA concentration (conc). Results: There were 699 EUS-guided aspirations in 625 consecutive patients with a cystic lesion on cross sectional imaging. 209 patients had a diagnosis established by surgical pathology or cytology. The median follow-up period was 1124d (37.5 mo). 125 mucinous lesions (71 IPMN and 54 MCN), 11 serous cystadenomas, 45 inflammatory cysts, 6 neuroendocrine tumors and 20 other cystic lesions were analyzed. Among the mucinous lesions, 46 were benign, 21 had borderline histology and 59 were malignant (carcinoma-in-situ or invasive). During the study period, there were 45 deaths. 30/45 (67%) of these patients had malignant mucinous lesions (8 malignant MCN, 22 malignant IPMN). The mortality rate for patients with malignant mucinous lesions was 51% (30/59) vs. 3% (2/67) for those with benign mucinous lesions (p < 0.001), and 0% for those with serous cystadenomas (p < 0.01). The mortality rate for malignant MCN was 53% (8/15) and 50% (22/44) for malignant IPMN. The mortality rate of patients with a mucinous lesion and who were >70 y old was 38% compared to 15% for <70y old (p < 0.01). The relative risk (RR) of mortality in patients with a malignant mucinous lesion was 34 (95% confidence interval [CI] 4.8-242.2). Age > 70y had a RR of mortality of 2.45 (95% CI 1.29-4.66). Cyst fluid CEA conc. > 500ng/ml was found in 80% of deaths v. 49% in surviving patients (p < 0.01) and had a RR of mortality of 2.95 (95% CI 1.31-6.66). Conclusions: Patients with a malignant mucinous cystic lesion have a significantly higher mortality rate (51%) than those with a benign mucinous cystic lesion (3%). Risk factors for death include increased age and cyst fluid CEA conc >500 ng/ml. The results of cyst fluid aspiration offer prognostic information in the management of patients with a cystic lesion.