Case Report: Targeted Therapy for Metastatic Solid Pseudopapillary Neoplasm of the Pancreas With CTNNB1 and PTEN Mutations

Case report: Clinical analysis and literature review of five cases of metastatic solid pseudopapillary tumor of the pancreas

Background

Solid pseudopapillary neoplasm of the pancreas (SPN) is a rare and low-grade malignant tumor. It mainly occurs in women of reproductive age, accounting for approximately 1-3% of all pancreatic tumors. SPN has a low incidence rate and is difficult to diagnose before surgery. Some cases may show local infiltration, but distant metastasis rarely occurs. Currently, there is no standardized treatment protocol for SPN.

Patient and methods

We have collected clinical data from 5 patients with solid pseudopapillary neoplasm (SPN) of the pancreas who presented with distant metastasis at our hospital. This study retrospectively analyzes their clinical manifestations, imaging characteristics, pathological findings, and treatment outcomes. The aim is to summarize the clinical features of SPN with distant metastasis, thereby improving the diagnosis, treatment, and prognosis prediction of this disease. This study also reviews relevant literature.

Results

The median age of the 5 patients was 32 years old, with a male-to-female ratio of 1:4. All patients underwent enhanced CT scans and were diagnosed with SPN through biopsy or surgical pathology. All 5 patients had liver metastases, and one patient had clavicular lymph node metastasis. Another patient had both lung and clavicular lymph node metastases. Three patients underwent curative surgery, one patient received chemotherapy combined with targeted immunotherapy and subsequently underwent TACE(Transcatheter arterial chemoembolization) and HAIC (Hepatic artery infusion chemotherapy) treatments due to progression. One patient received internal radiation therapy but experienced multiple relapses and eventually died due to complications. The follow-up period ranged from 7 to 53 months, with 2 patients succumbing to the disease.

Conclusion

As a low-grade tumor, SPN has a low rate of distant metastasis, typically occurring in only 5%-15% of cases. These metastases often lack characteristic clinical symptoms. Diagnosis can only be confirmed after exclusion of other lesions through imaging and pathological examination. The primary treatment for metastatic SPN is curative surgery, which can lead to a favorable prognosis.

CTNNB1 exon 3 mutations in metastatic solid pseudopapillary neoplasm of the pancreas

BACKGROUND AND OBJECTIVES

Solid pseudopapillary neoplasm (SPN) of the pancreas demonstrates an indolent disease course; however, some patients present with a "malignant" phenotype, including distant metastases resistant to chemotherapy. This analysis identifies molecular drivers of metastatic SPN using the world's largest clinicogenomics database.

METHODS

The American Association for Cancer Research Project Genomics Evidence Neoplasia Information Exchange was queried for primary and metastatic SPN samples. Sample-level genomic alterations were compared. A pan-pancreatic cancer analysis assessed relevant mutations among all metastatic pancreatic malignancies.

RESULTS

Among 28 SPN samples identified (n = 17 primary, n = 11 metastatic), the most commonly mutated gene was CTNNB1, (24/28 samples; 85.7%). Most mutations were missense (21/24; 87.5%) or in-frame deletions (3/24; 12.5%). The most common CTNNB1 mutations in primary SPN were exon 3 S37F/C missense mutations (6/16 profiled patients, 37.5%), contrasting exon 3 D32N/Y/H missense mutations in metastatic samples (6/11 profiled patients, 54.5%). Metastatic SPN had higher rates of CTNNB1 mutations than metastases from pancreatic ductal adenocarcinoma (72.7% vs. 1.1%; q < 0.0001), pancreatic neuroendocrine tumor (72.7% vs. 2.5%; q < 0.0001), and pancreatic acinar cell carcinoma (72.7% vs. 11.5%; q = 0.0254).

CONCLUSIONS

Missense mutations along exon 3 of CTNNB1 predominate metastatic SPN, differentiating these patients from those with metastases from analogous pancreatic malignancies.

A narrative review on rare types of pancreatic cancer: should they be treated as pancreatic ductal adenocarcinomas?

Pancreatic cancer is one of the deadliest malignancies in humans and it is expected to play a bigger part in cancer burden in the years to come. Pancreatic ductal adenocarcinoma (PDAC) represents 85% of all primary pancreatic malignancies. Recently, much attention has been given to PDAC, with significant advances in the understanding of the mechanisms underpinning disease initiation and progression, along with noticeable improvements in overall survival in both localized and metastatic settings. However, given their rarity, rare histological subtypes of pancreatic cancer have been underappreciated and are frequently treated as PDAC, even though they might present non-overlapping molecular alterations and clinical behavior. While some of these rare histological subtypes are true variants of PDAC that should be treated likewise, others represent separate clinicopathological entities, warranting a different therapeutic approach. In this review, we highlight clinical, pathological, and molecular aspects of rare histological types of pancreatic cancer, along with the currently available data to guide treatment decisions.

Solid pseudopapillary neoplasm of the pancreas with hepatic metastases: problems and strategies

Background

Solid pseudopapillary neoplasms of the pancreas with hepatic metastases are infrequent and difficult to diagnose, and treatment is uncertain.

Methods

A retrospective analysis of clinical data from patients with pancreatic solid pseudopapillary neoplasm (SPN) hepatic metastases who underwent surgery at the First Hospital of Jilin University from January 2005 to December 2021 was conducted. A total of 287 patients with SPN were included in the study, of which 8 (3%) developed liver metastases, all of whom were treated surgically and recovered well after surgery. The clinical presentation, imaging features, surgical treatment, histopathological examination, and postoperative follow-up data (mean 70 months; range 28-138 months) of the patients were recorded and analyzed. Clinical response strategies can be derived by reviewing previous studies on hepatic metastases of SPNs.

Results

For resectable hepatic metastases from pancreatic solid pseudopapillary neoplasms, early surgery with total resection of the primary tumor and metastasis has shown great efficiency and is associated with patient good prognosis. In patients presenting unresectable hepatic metastases, aggressive tumor reduction surgery resulted in the alleviation of clinical symptoms and reduction of tumor burden while potentially achieving long-term survival.

Conclusion

For hepatic metastases of SPNs, a preoperative liver tissue biopsy is beneficial for a definitive diagnosis. Surgery demonstrates excellent therapeutic efficacy and is considered the preferred curative treatment approach. This paper presents clinical experiences with SPN-related hepatic metastases at the Affiliated Hospital of Jilin University, which can be used to guide patient counseling in clinical practice.

Unraveling the enigma: A comprehensive review of solid pseudopapillary tumor of the pancreas

Solid pseudopapillary tumor of the pancreas (SPTP) is a rare neoplasm predominantly observed in young females. Pathologically, CTNNB1 mutations, β-catenin nuclear accumulation, and subsequent Wnt-signaling pathway activation are the leading molecular features. Accurate preoperative diagnosis often relies on imaging techniques and endoscopic biopsies. Surgical resection remains the mainstay treatment. Risk models, such as the Fudan Prognostic Index, show promise as predictive tools for assessing the prognosis of SPTP. Establishing three types of metachronous liver metastasis can be beneficial in tailoring individualized treatment and follow-up strategies. Despite advancements, challenges persist in understanding its etiology, establishing standardized treatments for unresectable or metastatic diseases, and developing a widely recognized grading system. This comprehensive review aims to elucidate the enigma by consolidating current knowledge on the epidemiology, clinical presentation, pathology, molecular characteristics, diagnostic methods, treatment options, and prognostic factors.

Malignant Solid Pseudopapillary Neoplasm of the Pancreas: An Orthogonal Analysis

BACKGROUND

Pancreatic solid pseudopapillary neoplasms (SPN) are generally indolent; however, some patients present with "malignant" SPN. An orthogonal analysis of multiple datasets was performed to investigate the utility of complete surgical resection (CSR) for malignant SPN.

METHODS

A systematic review was performed for cases of malignant SPN, defined as T4, N1, and/or M1. Malignant SPN was analyzed within the National Cancer Database (NCDB) and compared with T1-3N0M0 SPN. Predictors of malignant SPN were assessed, and treatments were analyzed by using survival analysis.

RESULTS

The systematic review yielded 164 cases of malignant SPN. Of 31 children, only one died due to malignant SPN. Among adults, CSR was associated with improved disease-specific survival (DSS) (P = 0.0002). Chemotherapy did not improve malignant SPN DSS, whether resected (P = 0.8485) or not (P = 0.2219). Of 692 adults with SPN within the NCDB, 93 (13.4%) had malignant SPN. Pancreatic head location (odds ratio [OR] 2.174; 95% confidence interval [CI] 1.136-4.166; P = 0.0186) and tumor size (OR 1.154; 95% CI 1.079-1.235; P < 0.0001) associated with the malignant phenotype. Malignant SPN predicted decreased overall survival (OS) compared with T1-3N0M0 disease (P < 0.0001). Resected malignant SPN demonstrated improved OS (P < 0.0001), including resected stage IV malignant SPN (P = 0.0003). Chemotherapy did not improve OS for malignant SPN, whether resected (P = 0.8633) or not (P = 0.5734). Within a multivariable model, resection was associated with decreased hazard of death (hazard ratio 0.090; 95% CI 0.030-0.261; P < 0.0001).

CONCLUSIONS

Approximately 13% of patients with SPN present with a malignant phenotype. Pediatric cases may be less aggressive. Resection may improve survival for malignant SPN, which does not appear chemosensitive.

A refractory liver metastatic solid pseudopapillary neoplasm pancreas harbored CTNNB1 mutation showed good response to celecoxib: A case report

Solid pseudopapillary neoplasm (SPN) of the pancreas is rare relatively low-grade malignant neoplasm and metastasis rarely. Surgical resection is the primary treatment option for primary and metastatic lesions of SPN, and chemotherapy is often ineffective in non-operable SPNs. SPNs are characterized by the presence of somatic CTNNB1 exon 3 mutations, leading to the activation of Wnt/β-catenin/Cox-2 signal pathway. Here, we firstly report that a refractory liver metastatic pancreatic SPN patient after the failure of multi-line chemotherapies benefited from the Cox-2 selective inhibitor (Celecoxib) based on CTNNB1 D32V mutation detected by next-generation sequencing (NGS), achieving a more than 22-month progression-free survival without any adverse events. Our case provides a potential treatment option for liver metastatic SPN patients with CTNNB1 mutations and highlights the application of NGS for the better treatment decision making.

Endocrine therapy for metastatic solid pseudopapillary neoplasm of the pancreas: A case report

Solid pseudopapillary neoplasm (SPN) of the pancreas is an extremely rare tumor, associated with favorable prognosis and long-term survival in patients with advanced disease. However, limited data exist on systemic therapy for such patients. Herein, we present a case of a young woman with a history of SPN, who progressed after multiple surgical resections and chemotherapy regimens. The immunohistochemistry (IHC) showed overexpression of estrogen receptors (ER) and progesterone receptors (PR) in tumor tissue. The patient started to receive tamoxifen and showed a durable response to endocrine therapy.

The Sex Features of Patients With Solid Pseudopapillary Neoplasms of the Pancreas: A Retrospective Study

Background

Solid pseudopapillary neoplasms of the pancreas (SPNs) in male patients are more frequently reported. The aim of the study was to evaluate the sex features of SPN and the risk factors that predict tumor recurrence.

Methods

From 2013 to 2019, patients who were pathologically confirmed to have SPNs were retrospectively reviewed. The baseline study parameters were compared between males and females. A logistic regression model was established to identify the independent risk factors for tumor recurrence.

Results

In total, 221 patients were included in this study. Of them, 53 patients (24.0%) were males. Male patients were older than female patients (39.1 vs 31.6 years, P=0.001), and the tumor size in male patients was smaller than that in female patients (50.38 vs 39.65 mm, P=0.038). The preoperative imaging diagnostic accuracy was significantly higher in females than in males (70.5% vs 54%, P=0.02). SPNs in male patients tended to be misdiagnosed with other malignant tumors (37.7% vs 10.7%, P<0.0001), with a more solid component observed in images (66.8% vs 24.7%, P<0.0001). For immunohistochemical staining, the expression of beta catenin was significantly lower in male patients (P=0.002), and the expression of vimentin was the opposite (P=0.01). The overall survival rate and disease-free survival were not different. Based on multivariate analysis, older age [hazard ratio (HR)= 1.094, 95% confidence interval (CI): 1.005-1.190] and KI 67 index grade III (HR=12.029, 95% CI: 2.399-60.311) were independent risk factors for tumor recurrence.

Conclusion

The clinical and imaging features of SPN in males were not in full accord with those in females; however, the differences did not influence prognosis.