Outcomes of Sporadic Pancreatic Ductal Adenocarcinoma and Pancreatic Adenocarcinoma Associated with Cystic Mucinous Neoplasms: A National Cancer Database Analysis

BACKGROUND: We aimed to assess the outcomes of patients with pancreatic adenocarcinoma associated with cystic mucinous neoplasms (PMAC) compared to pancreatic ductal adenocarcinoma (PDAC). We also examined the differential... [ view full abstract ]

BACKGROUND: We aimed to assess the outcomes of patients with pancreatic adenocarcinoma associated with cystic mucinous neoplasms (PMAC) compared to pancreatic ductal adenocarcinoma (PDAC). We also examined the differential role of adjuvant chemoradiation therapy (ACRT) in both groups.

METHODS: PMAC and PDAC diagnosed between 1998-2011 in the National Cancer Database were analyzed. The association between treatment and hazard of death was assessed using Kaplan-Meier and Cox proportional hazards modeling.

RESULTS: We identified 1479 patients with PMAC and 6157 patients with PDAC. Head of the pancreas tumors (80.6%) were most common, as were moderately differentiated tumors (49.2%), stage II disease (49.5%), and Whipple procedure (58.7%). There was a significantly increased median overall survival (OS) in patients with PMAC (21.2 months) compared to patients with PDAC (16.3 months, p<0.0001). In stratified analysis, stage I, II, and III PMAC patients had improved survival with ACRT (69.5, 31.9, and 23.3 months, respectively) compared to PDAC patients (29.8, 20.2, and 16.8 months, respectively all stages p<0.01). In PMAC patients, ACRT increased OS compared to surgery alone only in stage IIB and III (12, 13 months respectively). In PDAC the survival advantage with ACRT was seen across all stages I, IIA, IIB, III (8.5, 10.7, 8.3 and 7 months, respectively).

CONCLUSION: OS in PMAC patients is significantly higher than PDAC patients. Adjuvant chemoradiation therapy is associated with improved survival in all stages of PDAC, whereas only in stages IIB and III of PMAC patients, suggesting that early stage PMAC patients may be managed by surgery alone.