Solid pseudopapillary neoplasm of the pancreas: A retrospective single-center cohort study of 1,058 consecutive patients.

BACKGROUND

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare, low-grade malignant tumor, predominantly affecting young women. Although the overall prognosis of SPN is good, the understanding of its pathophysiological characteristics and the selection of treatment strategies remain insufficient.

METHODS

A retrospective analysis of 1058 consecutive patients with pathologically confirmed SPN was performed at a single institution. Clinicopathological characteristics, immunohistochemical profiles, targeted sequencing data, and overall survival were systematically evaluated.

RESULTS

The median age of the patients at diagnosis was 33 years, with females being the majority (78.1%). Most tumors were located in the body/tail (70.2%), larger than 3 cm (61.9%), while invasive features such as vascular invasion (1.6%), nerve invasion (7.0%), and lymph node metastasis (0.7%) were rare. Early-stage (stage I, II) patients were more common (99.1%). In recent years, the surgical procedures have significantly shifted towards minimally invasive and parenchyma-sparing surgery. The prognosis of SPN was excellent, with a 5-year survival of 97.9%. Molecular analysis revealed nearly universal CTNNB1 mutations (97%). High expression of progesterone receptor (PR, 97.2%) and low expression of estrogen receptor (ER, 7.7%) supported hormone dependence.

CONCLUSIONS

This large single-center cohort study confirms that SPN is a tumor with low malignant potential, and identifies the key clinicopathological and molecular factors associated with malignant features. Different hormone receptor profiles provide a theoretical basis for exploring hormone receptor-targeted therapy for advanced patients.