Sex differences in solid pseudopapillary neoplasm of the pancreas: A population-based study

Abstract

Objective: Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare tumor. This study aims to examine the clinicopathological features and surgical treatments of SPN and compare the clinical behavior and prognosis between men and women with SPN.

Methods: We collected the population data of patients with SPN diagnosed between 2004 and 2017 from the SEER database. The Kaplan-Meier method was used to analyze overall survival (OS) and disease-specific survival (DSS), and log-rank tests were used to evaluate the differences between subgroups. Univariate and multivariate Cox regression analyses were performed to screen out prognostic risk factors of SPN.

Results: A total of 378 patients with SPN were included, with 246 (65.1%) female patients. 1-, 3-, and 5-year overall survival rates were 98.9%, 95.7%, and 93.7%, respectively. Survival analysis revealed that regardless of stage, patients with SPN who underwent surgical interventions still had a significantly better prognosis than those without surgical interventions (P < .001). The patients with lymphatic dissection had a significantly better prognosis than those without lymphatic dissection (P < .001). Moreover, compared with female patients, male patients had significantly poorer OS and DSS (P < .001). Female SPN showed a bimodal age-frequency distribution with early-onset incidence at 28 years and late-onset peak incidence at 62 years, while male SPN presented a unimodal distribution with peak incidence at approximately age 64 years. In female patients, the tumor size in premenopausal females (<65 years old) was significantly larger than that in postmenopausal females (≥65 years old) (P < .001). Clinicopathological characteristic profiles were different not only between male SPN and premenopausal female SPN but also between premenopausal and postmenopausal female SPN.

Conclusion: SPN presents indolent behavior and predominantly occurs in young women. Regardless of stage, surgical intervention is recommended. Moreover, our study is the first large enough study to demonstrate sex-related discrepancies in SPN. Thus, different treatment strategies should be designed for patients of different sexes at different ages and hormone therapy is a promising approach for SPN.

Keywords: SEER; hormone; sex-related discrepancy; solid pseudopapillary neoplasm of the pancreas.

FIGURE 1

Flow diagram of patients selection in our study from the SEER database 2004‐2017

FIGURE 2

Solid pseudopapillary neoplasm (SPN) exhibited indolent behaviors. A, Survival analysis for overall survival in patients with SPNs; B, Survival analysis for disease‐specific survival in patients with SPNs; C, Lymph nodes metastasis status in SEER cohorts; D, Distant metastasis status in SEER cohorts

FIGURE 3

Survival analysis for overall survival and disease‐specific survival in patients with solid pseudopapillary neoplasm based on surgical intervention

FIGURE 4

Survival analysis for overall survival and disease‐specific survival in patients with solid pseudopapillary neoplasm based on lymphadenectomy

FIGURE 5

Solid pseudopapillary neoplasm (SPN) presented gender‐related discrepancies. A, Age‐gender distribution of male SPN and female SPN; B, Age‐frequency distribution of male SPN and female SPN; C, Survival analysis for overall survival and disease‐specific survival comparing male and female patients with SPN

FIGURE 6

The difference between premenopausal female and postmenopausal female. A, Survival analysis for overall survival and disease‐specific survival comparing premenopausal female and postmenopausal female with solid pseudopapillary neoplasm (SPN); B, Tumor size distribution of SPN in premenopausal female and postmenopausal female