Mixed neuroendocrine non-neuroendocrine neoplasms in gastroenteropancreatic tract

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) are a heterogeneous group of malignant neoplasms that can settle in the gastroenteropancreatic tract. They are composed of a neuroendocrine (NE) and a non-NE component in at least 30% of each tumour. The non-NE component can include different histological combinations of glandular, squamous, mucinous and sarcomatoid phenotypes, and one or both of the components can be low-or high grade malignant. Recent changes in the nomenclature of these neoplasms might lead to great deal of confusion, and the lack of specific clinical trials is the main reason why their management is difficult. The review aims to clarify the definition of MiNEN and analyze available evidence about their diagnosis and treatment options according to their location and extension through careful analysis of the available data. It would be important to reach a general consensus on their diagnosis in order to construct a classification that remains stable over time and facilitates the design of clinical trials that, due to their low incidence, will require long recruitment periods.

Surufatinib plus toripalimab in patients with advanced neuroendocrine tumours and neuroendocrine carcinomas: An open-label, single-arm, multi-cohort phase II trial

BACKGROUND

The programmed death 1 inhibitor toripalimab plus the angio-immuno kinase inhibitor surufatinib revealed a tolerable safety profile and preliminary efficacy in patients with advanced solid tumours in a phase I study.

PATIENTS AND METHODS

This was an open-label, single-arm, multi-cohort phase II study in China. Patients with advanced neuroendocrine tumours (NETs) or neuroendocrine carcinomas (NECs) or mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) who had failed or were intolerable of standard treatment were given surufatinib (250 mg orally, once daily) plus toripalimab (240 mg intravenously, once every 3 weeks). Primary end-point was investigator-assessed objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1. Secondary end-points included duration of response (DoR), disease control rate, progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

Forty patients were enrolled into two cohorts by tumour types (NET, n = 19; NEC-MiNEN, n = 21). ORRs (95% CIs) were 21.1% (6.1-45.6) and 23.8% (8.2-47.2) in the NET and NEC-MiNEN cohorts, respectively. Median DoR was 7.1 months (6.9-not evaluable [NE]) and 4.1 months (3.0-NE), respectively. Median PFS was 9.6 months (4.1-NE) and 4.1 months (1.5-5.5); median OS was 27.3 (15.3-NE) and 10.9 months (9.1-14.6), respectively. Overall, grade ≥ 3 treatment-related adverse events occurred in 18 (45.0%) patients.

CONCLUSIONS

Surufatinib plus toripalimab showed antitumour activity and a tolerable safety profile in patients with previously treated NETs/NECs/MiNENs. Further study of this combination regimen is ongoing for advanced NECs, for which current therapeutic options remain limited.

CLINICALTRIALS

gov: NCT04169672.

Incidence, survival, and prognostic factors for patients with gastrointestinal mixed neuroendocrine non-neuroendocrine neoplasms: a SEER population-based study

BACKGROUND

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) are a group of rare tumors with limited research currently available. This study aimed to analyze the incidence, survival, and prognostic factors of gastrointestinal MiNENs.

METHODS

We included data from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2019. We compared the clinicopathologic characteristics and survival rates between MiNENs and neuroendocrine tumors (NETs), and calculated the incidence of MiNENs. We utilized univariate and multivariate Cox analysis to assess independent factors of prognosis and established a nomogram to predict 1-, 2-, and 3-year cancer-specific survival (CSS). Calibration and receiver operating characteristic (ROC) curves were drawn to validate the accuracy and reliability of the model. Decision curve analysis (DCA) was used to assess the clinical utility of the model.

RESULTS

Patients with gastrointestinal MiNENs had a poorer prognosis than those with NETs. The overall incidence of gastrointestinal MiNENs has been increasing annually. Multivariate Cox regression analysis revealed that tumor size, lymph node metastasis, distant metastasis, and surgery were independent risk factors for CSS in MiNENs patients. Based on these risk factors, the 1-, 2-, and 3-year CSS nomogram model for MiNENs patients was established. Calibration, ROC, and DCA curves of the training and validation sets demonstrated that this model had good accuracy and clinical utility.

CONCLUSION

Gastrointestinal MiNENs are rare tumors with an increasing incidence rate. The nomogram model is expected to be an effective tool for personalized prognosis prediction in MiNENs patients, which may benefit clinical decision-making.

Discussion on the benefits of different treatment strategies in elderly and non-elderly patients with appendix MiNEN: a retrospective study based on SEER database

PURPOSE

To investigate the benefits of surgery alone and postoperative chemotherapy in elderly and non-elderly patients with appendiceal mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) and analyze the factors affecting the prognosis of patients with MiNEN of the appendix.

METHODS

Based on the Surveillance, Epidemiology, and End Results database (SEER) of the National Cancer Institute of the USA, 389 patients with appendiceal MiNENs from 2000 to 2016 were collected. All patients were distributed in the elderly group (≥ 60 years old) and the non-elderly group (< 60 years old) according to their age. The prognosis of the two groups of patients who received simple surgery and postoperative chemotherapy was analyzed and compared. The two treatment methods of the two tranches were matched by propensity score matching method. The effect of different treatment ways on the prognosis of sick persons was compared. The survivorship curves were painted by the Kaplan Meier method, log rank test was used to analyze the subsistence discrepancy of each group, and COX proportional risk model was used to analyze the factors affecting the prognosis of patients with appendiceal MiNENs.

RESULTS

No matter the overall survival rate (OS) or cancer-specific mortality (CSM) of the two treatment schemes, the prognosis of patients in the only surgery group was meaningfully higher than that in the postoperative chemotherapy group, with statistically significant difference in component comparison (χ² = 16.496, χ² = 16.860, P < 0.001). After propensity score matching of patients in each group, there was no striking discrepancy in the OS of patients in the only surgery group compared with those in the postoperative chemotherapy group, regardless of whether they were elderly patients or non-elderly patients (χ² = 3.205, χ² = 1.521, all P > 0.05), the CSM consequences are fitting in with the OS. The consequences of the multivariate COX regression model showed that age (≥ 60 years old), sex (female), high histological grade, and lymph node positive were all the influencing factors for the poor OS of patients with MiNEN; the CSM results are consistent with the OS.

CONCLUSION

For patients with appendix MiNEN, whether elderly or non-elderly patients (especially for non-elderly patients), surgical treatment may be a better choice.

Mixed neuroendocrine-non-neuroendocrine neoplasms of the digestive system: A mini-review

Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are rare mixed tumors containing both neuroendocrine (NE) and non-NE components. Each component must occupy at least 30% of the tumor volume by definition. Recent molecular evidence suggests MiNENs are clonal neoplasms and potentially harbor targetable mutations similar to conventional carcinomas. There have been multiple changes in the nomenclature and classification of MiNENs which has created some confusion among pathologists on how to integrate the contributions of each component in a MiNEN, an issue which in turn has resulted in confusion in communication with front-line treating oncologists. This mini review summarizes our current understanding of MiNENs and outline diagnosis, prognosis, and management of these neoplasms. The authors emphasize the importance of treating the most aggressive component of the tumor regardless of its percentage volume.

Evidence of a common cell origin in a case of pancreatic mixed intraductal papillary mucinous neoplasm-neuroendocrine tumor

Recently, the term mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN) has been proposed as an umbrella definition covering different possible combinations of mixed neuroendocrine-exocrine neoplasms. Among these, the adenoma plus neuroendocrine tumor (NET) combination is among the rarest and not formally recognized by the 2019 WHO Classification. In this setting, the debate between either collision tumors or true mixed neoplasms is still unsolved. In this report, a pancreatic intraductal papillary mucinous neoplasm (IPMN) plus a NET is described, and the molecular investigations showed the presence in both populations of the same KRAS, GNAS, and CDKN2A mutations and the amplification of the CCND1 gene. These data prove clonality and support a common origin of both components, therefore confirming the true mixed nature. For this reason, mixed neuroendocrine-exocrine neoplasms, in which the exocrine component is represented by a glandular precursor lesion (adenoma/IPMN) only, should be included into the MiNEN family.