Analysis of 340 Patients with Solid Pseudopapillary Tumors of the Pancreas: A Closer Look at Patients with Metastatic Disease

Introduction: Current literature addressing the treatment of solid pseudopapillary neoplasms (SPNs) of the pancreas is limited, particularly for patients with distant metastases. We aimed to define predictive indicators of survival in a large series of patients and assess the outcome of patients with distant metastases. Methods: The National Cancer Database was queried for patients diagnosed with SPNs of the pancreas between 1998 and 2011. Single predictor univariate analyses were performed on variables including demographics, tumor characteristics, and surgery outcomes, and multivariate Cox proportional hazards survival analysis was then completed with backward elimination. Results: Overall, 340 patients were identified: 82% were female, median age was 39 years, and 84% had no comorbidities. Patients undergoing any type of surgical resection experienced long-term survival (85% 8-year survival). Patients undergoing surgical resection (n = 296) had superior survival (hazard ratio [HR] 21 for no surgery, p < 0.0001), as did patients treated at academic centers and those with private insurance (HR 3.9, p = 0.009; HR 4.9, p = 0.007). Sex, age, tumor size, presence of lymph node metastases, positive surgical margins, and presence of distant metastases were not significant predictors of survival in multivariate analysis. Of 24 patients with distant metastases, seven were treated surgically and experienced long-term survival similar to that of patients without metastases treated surgically (HR 2, p = 0.48). Conclusion: SPNs of the pancreas are rare neoplasms with excellent overall survival; however, in a low number of patients they metastasize. Of the few patients with metastatic disease selected for resection, most experienced long-term survival.