4129 Background: Cystadenocarcinoma (CAC) of the pancreas is a rare pancreatic and therefore there is limited data on the characteristics, treatment and prognosis of this disease. Methods: Patients who underwent resection for CAC (n = 1,205) between 2003 and 2012 were identified from National Cancer Data Base. The clinicopathological characteristics and treatment outcomes were compared to patients with resected ductal adenocarcinoma (DAC) (n = 15,696). Cox-proportional hazard model was used to adjust for potential prognostic factors. A nomogram was constructed and validated to predict the outcomes of patients with CAC by using multiple variable Cox-proportional model and receiver operating characteristics curve methods. Results: Compared with resected DAC, patients with resected CAC are diagnosed at a younger age (58.7 vs. 61.2, p < 0.0001); female predominant (63.7% vs. 48.8%, p < 0.0001); more often Black (15.0% vs. 9.3%, p < 0.0001);had larger tumor (0-2, 2-4 and > 4cm:17.5%, 24.3%, 53.5% vs. 16.8%, 48.3% , 32.1%, respectively, p < 0.0001); have less total number of examined lymph nodes (10.6 vs. 14.5, p < 0.0001) and fewer positive lymph nodes(0.6 vs. 2.3, respectively). CAC patients were less likely to receive chemotherapy (28.8% vs. 62.5%, p < 0.0001) and radiation therapy (16.4% vs. 36.9%, p < 0.0001). CAC patients had significantly better overall survival than those with DAC (5 year survival: 55.6% vs. 17.3%, p < 0.0001). The survival advantage was primarily seen in patients with early stage disease (5 year survival: 70.9% vs. 36.9% in stage I patients, p < 0.0001, and 32.7% vs. 14.5% in stage II patients, p < 0.0001 respectively) and persisted after adjusting the known prognostic factors including age, AJCC staging, Charlson-Deyo score, type of surgery, chemotherapy, tumor size, and lymph node ratio (adjusted hazard ratio: 0.43, 95% confidence interval: 0.39-0.48, p < 0.0001). Conclusions: Patients with CAC had significantly better survival than those with pancreatic DAC even after controlling for known prognostic factors. The proposed nomogram could accurately predict patients’ outcome and may be used as a tool for clinical decision making.
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