Mixed neuroendocrine nonneuroendocrine neoplasms of the pancreas: a case report and literature review of pancreatic mixed neuroendocrine nonneuroendocrine neoplasm

Mixed pancreatic ductal adenocarcinoma and well-differentiated neuroendocrine tumor: A case report

BACKGROUND

Pancreatic mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are rare malignancies affecting the pancreas. The World Health Organization defines MiNENs as neoplasms composed of morphologically recognizable neuroendocrine and non-neuroendocrine components, each constituting 30% or more of the tumor volume. Adenocarcinoma-neuroendocrine carcinoma is the most frequent MiNEN combination. A well-differentiated neuroendocrine tumor (NET) component is rarely reported in MiNENs.

CASE SUMMARY

Here we report a rare case with intermingled components of ductal adenocarcinoma and grade 1 well-differentiated NET in the pancreas. The two tumors show distinct histology and significant differentiation discrepancy (poorly differentiated high grade adenocarcinoma and well-differentiated low grade NET), and also present as metastases in separate lymph nodes. Next generation sequencing of the two components demonstrates KRAS and TP53 mutations in the ductal adenocarcinoma, but no genetic alterations in the NET, suggesting divergent origins for these two components. Although tumors like this meet the diagnostic criteria for MiNEN, clinicians often find the diagnosis and staging confusing and impractical for clinical management.

CONCLUSION

Mixed NET/non-NET tumors with distinct histology and molecular profiles might be better classified as collision tumors rather than MiNENs.

Evaluating endoscopic ultrasound-guided tissue acquisition for diagnosis of small pancreatic neuroendocrine neoplasms

Background and study aims Although small hypervascular tumors are suspected to be pancreatic neuroendocrine tumors (p-NENs), their diagnosis and treatment are challenging. This study evaluated the usefulness of endoscopic ultrasound-guided tissue acquisition (EUS-TA) for diagnosis of small p-NENs. Methods All p-NEN lesions that underwent EUS-TA at our hospital between April 2018 and December 2023 were retrospectively analyzed. The diagnostic sensitivity of EUS-TA and the concordance rate of grading with EUS-TA and surgical specimens were examined. The lesions were grouped by size. Results The diagnostic sensitivity of EUS-TA was analyzed for 82 lesions, of which 44 were compared with postoperative specimens for grading. The definitive diagnosis was neuroendocrine tumor (NET) in 75 lesions, neuroendocrine carcinoma in five lesions, and mixed neuroendocrine non-neuroendocrine neoplasm in two lesions. Thirty tumors were ≤10 mm, 30 were 10 to 20 mm, and 22 were >20 mm, and the diagnostic sensitivities were 96.7%, 96.7%, and 90.9%, respectively. Concordance rates for grading were 94.4%, 82.4%, and 77.8% for tumors ≤10 mm, 10 to 20 mm, and ≥20 mm, respectively, with Cohen's kappa coefficients of 0.64, 0.48, and 0.40, respectively. Conclusions EUS-TA showed adequate diagnostic sensitivity and grading agreement for p-NENs of all sizes, allowing for determination of appropriate treatment.

Assessing the effectiveness and safety of surufatinib versus everolimus or sunitinib in advanced neuroendocrine neoplasms: insights from a real-world, retrospective cohort study using propensity score and inverse probability treatment weighting analysis

Background

While surufatinib, sunitinib, and everolimus have shown efficacy for advanced neuroendocrine neoplasms (NENs) in randomized controlled trials (RCTs), direct comparisons in a real-world setting remain unexplored. This gap highlights the clinical need to understand their comparative effectiveness and safety within the diverse Chinese population. Addressing this, our study provides insights into the real-world performance of these therapies, aiming to inform treatment selection and improve patient outcomes.

Methods

A retrospective, observational study was conducted at Fudan University Shanghai Cancer Center, including patients with advanced NENs treated with surufatinib, sunitinib, or everolimus between July 2020 and April 2023. Eligibility criteria focused on histologically confirmed, locally advanced, unresectable, or metastatic NENs, with patients having received at least one month of targeted therapy. We employed inverse probability weighting (IPW) with the propensity score (PS) matching to adjust for the bias of baseline characteristics. The assessment of covariates included age, sex, performance status, primary tumor site, functional status, genetic mutations, tumor differentiation, Ki67 index, tumor grade, metastasis site, and previous therapies. The primary outcome was progression-free survival (PFS), and secondary outcomes included objective response rate (ORR), disease control rate (DCR), and adverse events (AEs).

Results

The study enrolled 123, 56, and 68 locally advanced or metastatic NEN patients treated with surufatinib, sunitinib, and everolimus, respectively. Before adjusting for confounding factors, surufatinib was used less frequently as a first-line treatment compared to sunitinib and everolimus in pancreatic NENs (pNENs) (11.1% vs. 22.1%, P=0.057). Significant differences were noted in prior treatments and tumor characteristics between surufatinib and everolimus groups in extrapancreatic NENs (epNENs) (P<0.05). Post-IPW, these disparities were resolved (P>0.05). Surufatinib demonstrated superior median PFS (mPFS) in both pancreatic [8.30 vs. 6.33 months, hazard ratio (HR) 0.592, P<0.001] and epNENs (8.73 vs. 3.70 months, HR 0.608, P<0.001) compared to everolimus or sunitinib. Notably, male gender (HR 1.75, P=0.001), functional status (HR 2.09, P=0.01), Ki67 index >20% (HR 12.7, P=0.004), previous somatostatin analogue (SSA) treatment (HR 1.73, P=0.001), germline mutation (HR 5.62, P<0.001), poor differentiation (HR 7.45, P<0.001), liver metastasis (HR 1.72, P=0.001) and multiple treatment lines (HR 1.62 for 2nd line, P=0.04; HR 1.88 for ≥3rd line, P=0.01) were identified as negative prognostic factors for PFS. Conversely, dose adjustment (HR 0.63, P=0.009) and treatment with surufatinib (HR 0.58 for pNEN, P<0.001; HR 0.62 for epNEN, P=0.002) were correlated with longer PFS.

Conclusions

In a real-world Chinese cohort, surufatinib significantly outperformed sunitinib and everolimus in prolonging PFS among advanced NEN patients, with identifiable clinical features impacting survival, and conclusions regarding superiority should be interpreted with caution due to the retrospective design. Our findings underscore the need for prospective studies to further validate these results and explore additional predictive biomarkers for personalized treatment strategies.

Spatiotemporal heterogeneity and clinical challenge of pancreatic neuroendocrine tumors

During the course of pancreatic neuroendocrine tumors (NETs), they generally become more heterogeneous with individual cells exhibiting distinct molecular fingerprints. This heterogeneity manifests itself through an unequal distribution of genetically-variant, tumor cell subpopulations within disease locations (i.e., spatial heterogeneity) or changes in the genomic landscape over time (i.e., temporal heterogeneity); these characteristics complicate clinical diagnosis and treatment. Effective, feasible tumor heterogeneity detection and eradication methods are essential to overcome the clinical challenges of pancreatic NETs. This review explores the molecular fingerprints of pancreatic NETs and the spectrum of tumoral heterogeneity. We then describe the challenges of assessing heterogeneity by liquid biopsies and imaging modalities and the therapeutic challenges for pancreatic NETs. In general, navigating these challenges, refining approaches for translational research, and ultimately improving patient care are available once we have a better understanding of intratumoral spatiotemporal heterogeneity.