Pancreatic Solid Pseudopapillary Tumor Have Racial Difference But Same Good Prognosis in Three International Cohorts

Abstract

Introduction: Solid pseudopapillary neoplasm (SPN) of the pancreas are a rare and low-grade malignant entity. The rarity and lack of concern makes its clinicopathological features unclarified. This study aims to examine the clinicopathologic features and racial difference. Methods: The SPN of the pancreas database from 3 cohort, including one high volume medical center in USA, Asian and National Cancer Institution’s Surveillance, Epidemiology, and End Results (SEER) were queried from 2004 to 2020. We compared the perioperative variable, clinical data and overall survival (OS) and prognostic factor of recurrence. Result: A total of 286 patients with SPN were included. Most patients were female (81%), median age 38 years with peak incidence at 20-39 year-old female. While male SPN had peak incidence at age 50-59 year-old (p=.002). The variation of treatment strategy among institutions was noted. Higher lymphovascular invasion(LVI) (p=.02), perineural invasion (PNI) (p<.001) and R1 margin(p<.001) in one institution did not accompany with worse long-term survival in respective to overall survival (p=.43), SPN-specific survival (p=.69) and recurrence-free survival (p=.067). The lymph node positive was only predictor (reported as OR[95%CI]) of postoperative recurrence (2.2[1.38-2.99]; p=.007). Nor dose LVI, PNI, R1 margin, recurrence, and metastasis were significant factors in predicting survival. Conclusion: The survival is excellent in regard of metastasis or recurrence. The lymph node positive is the only recurrence predictor. Different surgical radicality, LVI, PNI and R1 margin do not differ survival. Indicated less radical resection is appropriate in SPN and treatment strategy could be different from pancreatic adenocarcinoma.