Background: Solid pseudopapillary neoplasm (SPN) is an uncommon pathology with a low-grade malignancy. Surgery is the milestone treatment. Nevertheless, despite appropriate management, some patients present recurrence. Risk factors associated with recurrence are unclear. The objective of this study was to identify the clinicopathological factors associated with recurrence in patients with the diagnosis of SPN treated with pancreatic resection.
Methods: In this retrospective single-center study, medical records of patients treated with pancreatic resection from January 2006 to January 2020 were evaluated. Patients with histological diagnosis of SPN were included. Survival analysis was performed to identify the clinicopathological factors related to recurrence.
Results: A total of 589 patients underwent pancreatectomy and, 74(12.6%) were diagnosed with SPN. Seventy patients (94.6%) were female and 4 were male. The median age was 20 years old and, 49(67%) patients were <28 years. The principal symptom was abdominal pain (n=62)(83.8%). The pancreatic head was the most frequent tumor localization (n=32)(43.2%). Distal pancreatectomy was performed in 33(44.6%) patients, followed by pancreaticoduodenectomy (n=32)(43.2%). The median tumor diameter was 7.9cm and, 24(32%) patients presented tumors ≥ 10 cm. Multivisceral resection was performed in 9(12.2%) patients. Four(5.4%) patients presented lymph node metastasis. R0 resection was achieved in all cases. The overall 90-days postoperative morbidity and mortality were 54% and 1.4%, respectively. The pancreatic fistula was the principal postoperative complication(n=27;36.5%). Six(8%) patients presented recurrence after pancreas resection. Liver metastasis was the most frequent recurrence site(n=5). After a median follow-up of 40.2 months, 9(12%) patients died. Five(6.8%) patients died of disease progression. The 1-3-and-5-year OS was 97.1%,90.2% and 79.9%, respectively. The 1-3-and-5-year RFS was 98.4%,89.9% and 87%, respectively. In the univariate Cox regression analysis, age ≥28 years (HR=8.61,95%CI:1.1–73.8), tumor diameter ≥10cm (HR=9.3,95%CI:1.12-79.6), invasion of adjacent organs (HR=7.45,95%CI:1.5–36.9), lymph node metastasis (pN+) (HR=16.8,95%CI:2.96–94.9) and, AJCC(TNM) Stage III (HR=10.1,95%CI:1.2–90.9) were identified as predictors for recurrence.
Conclusions: SPN is more frequently diagnosed in young women with a good overall prognosis after an R0 surgical resection even with disease recurrence. Age ≥28 years, larger tumors ≥10cm, invasion of adjacent organs, lymph node metastasis(N+) and, AJCC Stage III were predictors factors of recurrence in resected SPN.