Comparison between Endoscopic Submucosal Dissection and Transanal Endoscopic Microsurgery in Early Rectal Neuroendocrine Tumor Patients: A Meta-Analysis.

PURPOSE: To compare the effectiveness, safety and cost-effectiveness of endoscopic submucosal dissection (ESD) with transanal endoscopic microsurgery (TEM) in early rectal neuroendocrine tumor (RNET) patients. This article will provide reliable evidence for surgeons in regards to clinical decision-making. METHODS: Systematic literature retrieval was performed in Pubmed, Embase and Cochrane database from 2013/4/30 to 2023/4/30. Methodology validation was performed by using the Newcastle-Ottawa Scale (NOS). Data-analysis was conducted by using the Review manager version 5.3 software. RESULTS: A total of three retrospective studies were included in our meta-analysis. All eligible studies were considered to be high quality. By comparing baseline characteristics between TEM and ESD, patients in the TEM group seemed to be characterized by a larger tumor size and lower tumor level, even though no statistical significance was found. Clear statistical significance favoring TEM was identified in terms of R0 resection rate, procedure time and hospital stay. No statistical significance was found in terms of recurrence rate, adverse events rate and additional treatment rate. CONCLUSIONS: Compared with ESD, TEM was a more effective treatment modality for early RNET patients; it was associated with a relatively higher R0 resection rate and a similar degree of safety. However, the relatively higher cost and complicated manipulation restricted the promotion of TEM. Surgeons should opt for TEM as a primary treatment in patients with a larger tumor size and deeper degree of tumorous infiltration if the financial condition and hospital facility permit.

The combination of etoposide and platinum for the treatment of thymic neuroendocrine neoplasms: A retrospective analysis.

BACKGROUND: To provide real-world outcomes for the combination of etoposide and platinum as a first-line treatment for advanced thymic neuroendocrine neoplasms (TNENs). METHODS: Retrospective analysis was performed on patients with advanced TNENs confirmed by pathology who received etoposide combined with platinum as a first-line chemotherapy in our institution between 2010 and 2022. RESULTS: A total of 16 patients were included in this study. Twelve patients (75%) received etoposide combined with cisplatin, and four patients (25%) received etoposide combined with carboplatin. Efficacy was evaluated in all patients, with an objective response rate of 31.3%. One patient achieved a complete response, four achieved a partial response, and in eight patients the disease remained stable; the disease control rate was 81.3%. The median progression-free survival (PFS) was 7.2 months with a 95% confidence interval (CI) of 2.1-12.3 months. The median overall survival (OS) was 50.4 months with a 95% CI of 32.1-68.8 months. No significant difference in efficacy was observed between the treatment groups with regards to PFS (p = 0.095) and OS (p = 0.061). Treatment-related adverse events were observed in all 12 patients when evaluated for toxicity, manifesting as hematologic toxicity. Grade 3-4 bone marrow suppression occurred in six patients (50%). No treatment-related deaths were recorded. CONCLUSION: This retrospective analysis, conducted in a real-life setting, suggests that the combination of etoposide and platinum has a promising anti-tumor activity in advanced TNENs, with a clinically significant overall response rate.

Management of Functional Pancreatic Neuroendocrine Neoplasms.

OPINION STATEMENT: Functional pancreatic neuroendocrine neoplasms (pNENs) are rare and heterogeneous diseases in terms of both clinical and pathological aspects. These tumors secrete hormones or peptides, which may cause a wide variety of symptoms related to a clinical syndrome. The management of functional pNENs is still challenging for clinicians due to the need to control both tumor growth and specific symptoms. Surgery remains the cornerstone in the management of local disease because it can definitively cure the patient. However, when the disease is not resectable, a broad spectrum of therapeutic options, including locoregional therapy, somatostatin analogs (SSAs), targeted therapies, peptide-receptor radionuclide therapy (PRRT), and chemotherapy, are available. The present review summarizes the main key issues regarding the clinical management of these tumors, providing a specific highlight on their therapeutic approach.

Outcomes and survival in patients with advanced intestinal neuroendocrine tumours on home parenteral nutrition, an international multicentre retrospective cohort study.

BACKGROUND AND AIMS: Only limited information is available on the use of home parenteral nutrition (HPN) in patients with advanced neuroendocrine tumours (NETs) causing intestinal failure (IF). This study aims to report the outcomes of the explore the use of HPN in this patient cohort, in the largest case series to date. METHODS: A retrospective study in the United Kingdom and the Netherlands was performed, using the UK National British Artificial Nutrition Survey (BANS) and local databases in the Netherlands. Data regarding age, sex, NET grading, staging, treatment, HPN characteristics and survival outcomes were collected. RESULTS: Data were collected on 41 patients (n = 18 males, 44%) with a median age of 65. Most primary tumours were in the small bowel (n = 35, 85%). The NETs were Grade 1 (n = 16, 39%), Grade 2 (n = 7, 17%), Grade 3 (n = 1, 2%). In 28 patients (n = 68%) there was stage IV disease with metastases located in the peritoneum, mesentery and or liver. There were two indications for HPN; short bowel syndrome (n = 27, 66%) and inoperable malignant bowel obstruction (n = 14, 34%). The median period on HPN was 11 months (interquartile range 4-25 months). 11 patients were still alive and receiving HPN treatment after 2 years, and 6 patients after 3 years. Six patients (22%) with short bowel syndrome (SBS) could be weaned from HPN. There was a statistically significant improved survival for patients with short bowel syndrome (median 24 months) compared to inoperable malignant bowel obstruction (median 7 months). The catheter-related bloodstream infection rate was comparable to other HPN patient cohorts at 1.0 per 1000 catheter days. CONCLUSION: This study shows that HPN can be used safely in patients with NET and IF to increase survival beyond that reasonably expected in the context of either short bowel syndrome or inoperable malignant bowel obstruction. Patients with short bowel syndrome are most likely to benefit. Further prospective studies are necessary to validate survival benefits and to demonstrate the effect of HPN on quality of life.

Lifestyle Factors and Development and Natural Course of Gastroenteropancreatic Neuroendocrine Tumors: A Review of the Literature.

INTRODUCTION: The rarity of neuroendocrine tumors (NETs) and their heterogeneous presentation complicate the identification of risk factors for their development and natural course. Several tumor-specific prognostic factors have been identified, but less attention has been given to lifestyle factors as risk and prognostic factors. This review aimed to identify studies on smoking, alcohol use, physical activity, diet, body mass index (BMI), and diabetes and their association with the development and course of gastroenteropancreatic (GEP-) NETs. METHODS: The literature was systematically searched for articles on lifestyle factors and NETs available via PubMed and Embase. Study quality was assessed using the Newcastle-Ottawa scale. RESULTS: A total of 25 eligible studies out of 3,021 screened articles were included. Most studies reported on smoking and alcohol, reporting conflicting results. Diet seems to have an influence on NET development, but few studies were published. Articles reporting on BMI were not unanimous on the effect on GEP-NETs. Diabetes was reported as a risk factor for NETs, while a protective effect was observed with metformin use. CONCLUSION: Different tissues, i.e., the pancreas and small intestine, may respond differently to exposure to alcohol and smoking. Evidence for diet so far is too limited to draw conclusions. Diabetes seems to be an important risk factor for the development of pancreatic NETs with a protective role in disease progression, while BMI is not unequivocally associated with the development and prognosis of NETs. Hence, our findings suggest that lifestyle factors play an important role in NET development as a disease course. Future research should consider lifestyle as an influence on disease progression and treatment response.

Substance use and esophageal neuroendocrine neoplasm: A case-control study.

Esophageal neuroendocrine neoplasms (NEN) are extremely rare and little is known about their risk factors. To identify the potential risk factors, we evaluated whether the history of substance use, including alcohol, tobacco and areca nut consumption was associated with esophageal NEN. Forty-one esophageal NEN patients diagnosed between 2002 and 2019 from 17 hospital in Taiwan were enrolled as the cases. Controls were participants who received complete esophagogastroduodenoscopy in an endoscopic cohort and 123 eligible controls were matched to 41 cases (3:1) on age and gender. Alcohol drinking and cigarette smoking significantly increased the risk of esophageal NEN, with about a fourfold risk increase in alcohol drinkers as well as cigarette smokers. Moreover, use of cigarette smoking and alcohol consumption in combination demonstrated the highest risk of esophageal NEN with the risk increasing up to 20 times compared with non-users. Alcohol consumption and cigarette smoking significantly increase risk of esophageal NEN and both alcohol and cigarette users had the highest risk.

The optimal duration of capecitabine plus temozolomide in patients with well-differentiated pancreatic NETs with or without maintenance therapy.

BACKGROUND: The optimal duration of capecitabine combined with temozolomide (CapTem) for metastatic pancreatic neuroendocrine tumours (PanNETs) remains controversial. The present study aimed to assess the activity and safety of prolonged CapTem and Cap maintenance therapy in patients with metastatic PanNETs. METHODS: Retrospective real-world data of 94 patients with metastatic PanNETs were obtained from one cancer centre. Fifteen patients were treated with Cap maintenance therapy after fixed 12-13 cycles of CapTem (group I), 44 patients were treated with prolonged CapTem until disease progression (group II), and 35 patients were treated with fixed 12-13 cycles of CapTem (group III). RESULTS: The mean ± SE follow-up period was 41.79 ± 26.31 months. The median CapTem treatment duration was 12 months in group I and 14 months in group II. The median time to best partial response was 12 months both in groups I and group II. The objective response rates of groups I and II were significantly higher than those of group III (73.3%, 41.9%, and 20%, respectively, p = .002). The median progression-free survival (mPFS) of group I and group II was significantly higher than that of group III (35 months, 26 months vs. 19 months, p < .001). Safety analysis of the three groups indicated rare events of grade 3-4 toxicities, with nausea, vomiting, fatigue, and anaemia being the most common adverse effects. CONCLUSIONS: Patients with PanNETs who responded well to CapTem treatment may benefit from prolonged CapTem and Cap maintenance therapy after fixed cycles. Prospective studies are encouraged to further explore the prolonged CapTem treatment and maintenance therapy.

An Update on the Management of Mixed Neuroendocrine-Non-neuroendocrine Neoplasms (MiNEN).

OPINION STATEMENT: The classification of mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) is evolving, and no clear management guidelines are currently available. However, recent studies provide insight into factors affecting outcomes and could help develop treatment decisions for patients with these rare malignancies. The majority of MiNENs have a poorly differentiated neuroendocrine carcinoma (NEC) component which is associated with an aggressive clinical course and poor outcomes. Due to the paucity of clinical trials, strategies adopted in gastrointestinal cancers and NECs are used to manage MiNENs. It is also to be noted that the thoracic neuroendocrine neoplasm WHO 2021 classification does not recognize MiNEN terminology but suggests an equivalent terminology called "combined neuroendocrine non neuroendocrine neoplasm." Surgical management is appropriate in early-stage disease with a low threshold for addition of adjuvant chemotherapy. Multimodality treatment with chemotherapy offers a survival benefit in advanced disease or when surgical resection is not possible without significant morbidity. Chemotherapy should be directed at the more aggressive component which is often the NEC component. In addition, molecular testing should be employed to evaluate patients for enrollment in clinical trials and other targeted treatments. Being a rare disease with retrospective studies and case series providing the majority of data on treatment selection, it is essential to include more granular details of pathology (e.g., Ki-67, mitotic index, percentage of each component, staging information) and treatment modalities (e.g., type and duration, rationale, radiologic response, survival outcomes) in future studies to make systematic reviews possible and help derive meaningful conclusions.

Clinical utility of endoscopic submucosal dissection using the pocket-creation method with a HookKnife and preoperative evaluation by endoscopic ultrasonography for the treatment of rectal neuroendocrine tumors.

BACKGROUND: Various endoscopic methods have been developed to remove small rectal neuroendocrine tumors (NETs). This study aimed to evaluate the clinical utility of endoscopic submucosal dissection using the pocket-creation method (ESD-PCM) with a HookKnife, following preoperative evaluation by endoscopic ultrasonography (EUS), for the treatment of rectal NETs. METHODS: We analyzed retrospectively consecutive patients who underwent ESD-PCM with a HookKnife for the removal of rectal NETs, with a size less than 10 mm, at Mie University Hospital between June 2015 and December 2019. All the rectal NETs were resected by ESD-PCM with a HookKnife. The R0 resection rate, procedure time, adverse event rate, diagnostic accuracy of tumor size and invasion depth evaluated by preoperative EUS, and follow-up outcome were evaluated retrospectively. RESULTS: The study group comprised 12 patients with 12 resected lesions. The median tumor size of the resected specimens was 5 mm and the size and invasion depth of each tumor was approximately equal to that predicted by preoperative EUS. R0 resection was achieved in all cases, without adverse events. The median procedure time was 50.5 min, which did not differ from previous studies. No recurrence was observed during the median follow-up period of 34.4 months (range, 5.2-60.0 months). CONCLUSIONS: ESD-PCM with a HookKnife provides a favorable clinical utility for removing rectal NETs, with high R0 resection rate and good follow-up outcome. In addition, EUS is useful for evaluating preoperatively the size and invasion depth of rectal NETs.

Dynamic Interactions Between the Immune System and the Neuroendocrine System in Health and Disease.

The immune system and the neuroendocrine system share many common features. Both consist of diverse components consisting of receptors and networks that are widely distributed throughout the body, and both sense and react to external stimuli which, on the one hand control mechanisms of immunity, and on the other hand control and regulate growth, development, and metabolism. It is thus not surprising, therefore, that the immune system and the neuroendocrine system communicate extensively. This article will focus on bi-directional immune-endocrine interactions with particular emphasis on the hormones of the hypothalamus-pituitary-thyroid (HPT) axis. New findings will be discussed demonstrating the direct process through which the immune system-derived thyroid stimulating hormone (TSH) controls thyroid hormone synthesis and bone metamorphosis, particularly in the context of a novel splice variant of TSHß made by peripheral blood leukocytes (PBL). Also presented are the ways whereby the TSHß splice variant may be a contributing factor in the development and/or perpetuation of autoimmune thyroid disease (AIT), and how systemic infection may elicit immune-endocrine responses. The relationship between non-HPT hormones, in particular adipose hormones, and immunity is discussed.

Immunotherapy in Neuroendocrine Neoplasms: Where Are We Now?

OPINION STATEMENT: Immune checkpoint inhibitors (ICIs) represent a breakthrough in the management of many hard-to-treat cancers over the past decade with demonstrable improvement in survival outcomes. We reviewed the state of the art of ICIs in neuroendocrine neoplasms (NENs). While ICIs have become part of the standard of care for the management of small cell lung cancer (SCLC), their role is still unclear in the management of extra-pulmonary (EP) poorly differentiated neuroendocrine carcinomas (NECs) as well as in the management of well-differentiated neuroendocrine tumors (NETs). Conflicting results derived from the various studies in NETs and EP NECs therefore for specific settings, such as the lung NETs, or therapeutic regimen, e.g., combo vs single agent, for ICIs benefit. Therefore, at the moment, no ICIs approach is justified for NETs and EP NECs in clinical practice. Future investigations should be designed with the aim to overcome the several limitations of the current trials, e.g., lacking of a central pathology review or heterogeneity of the cohorts, in order to reduce the risk of biases. Future trials combining ICIs with other biological agents are welcome. This review aims to provide a comprehensive overview of the biological rationale and evolving clinical applications of the use of ICIs in the management of NENs (both well-differentiated and poorly differentiated groups).

Treatment personalization in gastrointestinal neuroendocrine tumors.

OPINION STATEMENT: The clinical scenario of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) is continuously changing due to significant improvements in the definition of their molecular landscapes and the introduction of innovative therapeutic approaches. Many efforts are currently employed in the integration of the genetics/epigenetics and clinical information. This is leading to an improvement of tumor classification, prognostic stratification and ameliorating the management of patients based on a personalized approach.

An Update on the Management of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH).

OPINION STATEMENT: DIPNECH is caused by an idiopathic proliferation of pulmonary neuroendocrine cells which can lead to bronchiolitis and multifocal lung neuroendocrine tumors. Patients often present with chronic cough and dyspnea. Larger NETs may develop malignant potential. Somatostatin analogs can palliate chronic symptoms, particularly cough. Surgical resection can be considered for relatively large (e.g. >1 cm), progressive tumors.

Prognosis after surgery for multiple endocrine neoplasia type 1-related pancreatic neuroendocrine tumors: Functionality matters.

BACKGROUND: Metastasized pancreatic neuroendocrine tumors are the leading cause of death in patients with multiple endocrine neoplasia type 1. Aside from tumor size, prognostic factors of pancreatic neuroendocrine tumors are largely unknown. The present study aimed to assess whether the prognosis of patients with resected multiple endocrine neoplasia type 1-related nonfunctioning pancreatic neuroendocrine tumors differs from those with resected multiple endocrine neoplasia type 1-related insulinomas and assessed factors associated with prognosis. METHODS: Patients who underwent resection of a multiple endocrine neoplasia type 1-related pancreatic neuroendocrine tumors between 1990 and 2016 were identified in 2 databases: the DutchMEN Study Group and the International MEN1 Insulinoma Study Group databases. Cox regression was performed to compare liver metastases-free survival of patients with a nonfunctioning pancreatic neuroendocrine tumors versus those with an insulinoma and to identify factors associated with liver metastases-free survival. RESULTS: Out of 153 patients with multiple endocrine neoplasia type 1, 61 underwent resection for a nonfunctioning pancreatic neuroendocrine tumor and 92 for an insulinoma. Of the patients with resected lymph nodes, 56% (18/32) of nonfunctioning pancreatic neuroendocrine tumors had lymph node metastases compared to 10% (4/41) of insulinomas (P = .001). Estimated 10-year liver metastases-free survival was 63% (95% confidence interval 42%-76%) for nonfunctioning pancreatic neuroendocrine tumors and 87% (72%-91%) for insulinomas. After adjustment for size, World Health Organization tumor grade, and age, nonfunctioning pancreatic neuroendocrine tumors had an increased risk for liver metastases or death (hazard ratio 3.04 [1.47-6.30]). In pancreatic neuroendocrine tumors ≥2 cm, nonfunctioning pancreatic neuroendocrine tumors (2.99 [1.22-7.33]) and World Health Organization grade 2 (2.95 [1.02-8.50]) were associated with liver metastases-free survival. CONCLUSION: Patients with resected multiple endocrine neoplasia type 1-related nonfunctioning pancreatic neuroendocrine tumors had a significantly lower liver metastases-free survival than patients with insulinomas. Postoperative counseling and follow-up regimens should be tumor type specific and at least consider size and World Health Organization grade.

Pancreatic insufficiency following pancreatectomy: Does underlying tumor syndrome confer a greater risk?

BACKGROUND: The risk of postoperative pancreatic exocrine insufficiency (PPEI) is unknown in patients with multiple endocrine neoplasia type I (MEN1) and von Hippel-Lindau (VHL) who require resection of pancreatic neuroendocrine tumors (PNETs). METHODS: A retrospective review of patients who underwent resection of PNETs at the National Institutes of Health from 2007 to 2019 was performed. RESULTS: Our cohort included 82 patients (VHL n = 25, MEN1 n = 20, sporadic n = 37), 6 of whom developed PPEI. While VHL compared to all non-VHL patients (p = 0.046), non-functional PNETs (p = 0.050), and pancreaticoduodenectomy (PD) (p=<0.001) were associated with higher rates of PPEI on univariate analysis, only PD was found to be an independent predictor of PPEI on multivariate analysis (OR 14.43, 95% CI 1.43-145.8, p = 0.024). CONCLUSIONS: The rate of PPEI in patients with hereditary tumor syndromes was similar to that of sporadic PNETs. PD was independently associated with PPEI, and this increased risk should be included in preoperative counseling.

Risk factors for pancreas and lung neuroendocrine neoplasms: a case-control study.

PURPOSE: Neuroendocrine neoplasia (NEN) has been displaying an incremental trend along the last two decades. This phenomenon is poorly understood, and little information is available on risk factor for neuroendocrine neoplasia development. Aim of this work is to elucidate the role of potentially modifiable risk factors for pancreatic and pulmonary NEN. METHODS: We conducted a case-control study on 184 patients with NEN (100 pancreas and 84 lung) and 248 controls. The structured questionnaire included 84 queries on socio-demographic, behavioral, dietary and clinical information. RESULTS: Increased risk was associated with history of cancer ("other tumor", lung OR = 7.18; 95% CI: 2.55-20.20 and pancreas OR = 5.88; 95% CI: 2.43-14.22; "family history of tumor", lung OR = 2.66; 95% CI: 1.53-4.64 and pancreas OR = 1.94; 95% CI: 1.19-3.17; "family history of lung tumor", lung OR = 2.56; 95% CI: 1.05-6.24 and pancreas OR = 2.60; 95% CI: 1.13-5.95). Type 2 diabetes mellitus associated with an increased risk of pancreatic NEN (OR = 3.01; 95% CI: 1.15-7.89). CONCLUSIONS: Besides site-specific risk factors, there is a significant link between neuroendocrine neoplasia and cancer in general, pointing to a shared cancer predisposition.

Molecular Characterization of Appendiceal Goblet Cell Carcinoid.

Goblet cell carcinoid (GCC) is a distinct subtype of appendiceal neoplasm that exhibits unique clinical and pathologic features. We aimed to reveal the molecular profiles of GCC compared with other appendiceal tumors, such as adenocarcinomas and neuroendocrine tumors. A total of 495 appendiceal tumor samples (53 GCCs, 428 adenocarcinomas, and 14 neuroendocrine tumors) were tested with next-generation sequencing (NGS) on a 592-gene panel and IHC. Microsatellite instability (MSI)/mismatch repair (MMR) status was tested with a combination of NGS, IHC, and fragment analyses. Tumor mutational burden (TMB) was evaluated by NGS, and PD-L1 expression was tested by IHC (SP142). The most prevalent mutated genes within GCCs were TP53 (24.0%), ARID1A (15.4%), SMAD4 (9.4%), and KRAS (7.5%). Pathway-specific alterations were dominantly observed in cell cycle, MAPK, epigenetic, and TGFß signaling pathways. GCCs as compared with adenocarcinomas exhibited significantly lower mutation rates in KRAS, GNAS, and APC, and significantly higher mutation rates in CDH1, CHEK2, CDC73, ERCC2, and FGFR2 GCCs as compared with neuroendocrine tumors showed significantly lower mutation rates in KRAS, APC, BRCA2, and FANCA In GCCs, MSI high/MMR deficient, TMB high (≥17 mutations/Mb), and PD-L1 expression were seen in 0.0%, 0.0%, and 2.0% of tumors, respectively. No significant differences were observed in any immunotherapy-related markers examined when compared with adenocarcinomas and neuroendocrine tumors. In conclusion, GCCs had considerably distinct mutational profiles compared with appendiceal adenocarcinomas and neuroendocrine tumors. Understanding these molecular characteristics may be critical for the development of novel and more effective treatment strategies for GCC.

Merkel cell carcinoma: Preparing to go the distance.

INTRODUCTION: Merkel cell carcinoma (MCC) is a rare and aggressive malignancy of the skin, with poor clinical outcomes. Typical conditions include a rapidly growing, solitary dome-shaped, violaceous nodule. Several root causes have been identified - sun exposure, age, lighter skin, immunocompromised state, and polyomavirus infection. Wide local excision is the best treatment. The tumour is radiotherapy-responsive. However, the success rate of the treatment with chemotherapy is rather limited. Immunotherapy has shown promising results. Early detection is important to prevent morbidity and mortality. CASE REPORT: In this literature work, we reported on a particular case of MCC, as exhibited by an 84-year-old Chinese woman, and discussed the clinical features and management of MCC. DISCUSSION: We highlighted that MCC cases have a link to the polyomavirus 5. Patients who were identified with the Polyomavirus 5, and underwent immunotherapy, were seen to depict much better prognosis.

LIN28B promotes the development of neuroendocrine prostate cancer.

Therapy-induced neuroendocrine prostate cancer (t-NEPC) is a highly aggressive subtype of prostate cancer with poor patient survival. Emerging evidence indicates that t-NEPC can develop when prostate adenocarcinoma cells acquire cancer stem-like cell signaling in the presence of androgen receptor inhibition, followed by redifferentiation toward neuroendocrine lineage and subsequent t-NEPC progression. Whether the stem-like signaling is controlled by the core pluripotency stem cell genes (e.g., LIN28 and SOX2) remains unknown. Here, we report that the transcription of the LIN28B isoform and SOX2 were co-upregulated in t-NEPC patient tumors, patient-derived xenografts, transgenic mice, and cell models. Immunohistochemistry validated that LIN28B and SOX2 protein expression were elevated in t-NEPC patient biopsies. Using prostate adenocarcinoma and t-NEPC cell models, we demonstrated that LIN28B induced a stem-like gene network, neuroendocrine biomarkers, and neuroendocrine cell morphology. LIN28B depletion by CRISPR inhibited t-NEPC tumorigenesis and xenograft growth. These LIN28B functions were mediated mainly through the suppression of let-7 miRNA expression, resulting in de-repression of the transcription factor HMGA2 and HMGA2-mediated SOX2 expression. This study revealed a mechanism by which t-NEPC can develop through the LIN28B/let-7/SOX2 axis that regulates a cancer cell stem-like gene network, highlighting LIN28B as a potential therapeutic target in t-NEPC.