What is New in the 2019 World Health Organization (WHO) Classification of Tumors of the Digestive System: Review of Selected Updates on Neuroendocrine Neoplasms, Appendiceal Tumors, and Molecular Testing

Roles of long non‑coding RNA SNHG16 in human digestive system cancer (Review)

The incidence of tumors in the human digestive system is relatively high, including esophageal cancer, liver cancer, pancreatic cancer, gastric cancer and colorectal cancer. These malignancies arise from a complex interplay of environmental and genetic factors. Among them, long non‑coding RNAs (lncRNAs), which cannot be translated into proteins, serve an important role in the development, progression, migration and prognosis of tumors. Small nucleolar RNA host gene 16 (SNHG16) is a typical lncRNA, and its relationship with digestive system tumors has been widely explored. The prevailing hypothesis suggests that the principal molecular mechanism of SNHG16 in digestive system tumors involves it functioning as a competitive endogenous RNA that interacts with other proteins, regulates various genes and influences a downstream target molecule. The present review summarizes recent research on the relationship between SNHG16 and numerous types of digestive system cancer, encompassing its biological functions, underlying mechanisms and potential clinical implications. Furthermore, it outlines the association between SNHG16 expression and pertinent risk factors, such as smoking, infection and diet. The present review indicated the promise of SNHG16 as a potential biomarker and therapeutic target in human digestive system cancer.

A neuroendocrine tumor arising in a tailgut cyst: Case report and literature review

INTRODUCTION AND IMPORTANCE

Cystic lesions in the retrorectal space include developmental abnormality, inflammatory process, and tumor-relevant cysts. Among them, the tailgut cyst is the most common lesion which is featured by the complex epithelium lining the wall. It is generally accepted that tailgut cysts are embryonic residues and are mostly benign, but there are also reports about malignant transformation and even metastasis.

CASE PRESENTATION

A 44-year-old female complained a sacrococcygeal discomfort more than one year. The imaging diagnosis was an infectious cyst. After surgery, a solid region was defined in a cyst. Morphologically, the region was composed of bland epithelia forming glandular or ribbon-like structure, with round nuclei and fine chromatin. Immunohistochemically, the cells were positive for CK7, CD56 and synaptophysin. The Ki-67-positive cells were about 1 %. The final diagnosis is a low-grade neuroendocrine tumor arising in a tailgut cyst. The patient was living without recurrence by the follow-up of 20 months after surgery.

CLINICAL DISCUSSION

By reviewing the previously reported NET arising from tailgut cysts, we summarized 29 cases of neuroendocrine neoplasms that reported detailed information, and the majority are women. We found that the higher-grade tumor presented a higher tendency of distant metastasis or recurrence after surgery. Complete resection and full evaluation by pathologists are necessary to get a correct diagnosis and avoid disease progression.

CONCLUSION

We reported the rare case of NET G1 arising from a tailgut cyst and reviewed relevant reports, in order to broaden differential diagnoses when an isolated mass is identified in the retrorectal space.

An Illustrated Review of the Recent 2019 World Health Organization Classification of Neuroendocrine Neoplasms: A Radiologic and Pathologic Correlation

ABSTRACT

Recent advances in molecular pathology and an improved understanding of the etiology of neuroendocrine neoplasms (NENs) have given rise to an updated World Health Organization classification. Since gastroenteropancreatic NENs (GEP-NENs) are the most common forms of NENs and their incidence has been increasing constantly, they will be the focus of our attention. Here, we review the findings at the foundation of the new classification system, discuss how it impacts imaging research and radiological practice, and illustrate typical and atypical imaging and pathological findings. Gastroenteropancreatic NENs have a highly variable clinical course, which existing classification schemes based on proliferation rate were unable to fully capture. While well- and poorly differentiated NENs both express neuroendocrine markers, they are fundamentally different diseases, which may show similar proliferation rates. Genetic alterations specific to well-differentiated neuroendocrine tumors graded 1 to 3 and poorly differentiated neuroendocrine cancers of small cell and large-cell subtype have been identified. The new tumor classification places new demands and creates opportunities for radiologists to continue providing the clinically most relevant report and on researchers to design projects, which continue to be clinically applicable.

Clinical Intricacies and Advances in Neuroendocrine Tumors: An Organ-Based Multidisciplinary Approach

ABSTRACT

Neuroendocrine neoplasms (NENs) are rare neoplasms originating from neuroendocrine cells, with increasing incidence due to enhanced detection methods. These tumors display considerable heterogeneity, necessitating diverse management strategies based on factors like organ of origin and tumor size. This article provides a comprehensive overview of therapeutic approaches for NENs, emphasizing the role of imaging in treatment decisions. It categorizes tumors based on their locations: gastric, duodenal, pancreatic, small bowel, colonic, rectal, appendiceal, gallbladder, prostate, lung, gynecological, and others. The piece also elucidates the challenges in managing metastatic disease and controversies surrounding MEN1-neuroendocrine tumor management. The article underscores the significance of individualized treatment plans, underscoring the need for a multidisciplinary approach to ensure optimal patient outcomes.

Advancements in Neuroendocrine Neoplasms: Imaging and Future Frontiers

Neuroendocrine neoplasms (NENs) are a diverse group of tumors with varying clinical behaviors. Their incidence has risen due to increased awareness, improved diagnostics, and aging populations. The 2019 World Health Organization classification emphasizes integrating radiology and histopathology to characterize NENs and create personalized treatment plans. Imaging methods like CT, MRI, and PET/CT are crucial for detection, staging, treatment planning, and monitoring, but each of them poses different interpretative challenges and none are immune to pitfalls. Treatment options include surgery, targeted therapies, and chemotherapy, based on the tumor type, stage, and patient-specific factors. This review aims to provide insights into the latest developments and challenges in NEN imaging, diagnosis, and management.

UBXN11 Predicts as a Poor Index for Colorectal Cancer and Contributes to the Tumorigenesis by Activating NF-κB Signaling

BACKGROUND

The complex mechanisms of colorectal cancer (CRC) pathogenesis and progression remain poorly understood. This study endeavors to unravel the role of UBXN11within the context of CRC.

METHODS

UBXN11 expression level in CRC, stomach adenocarcinoma and esophageal carcinoma, and the overall survival in corresponding cancers were analyzed using UALCAN database. Human CRC cell lines and xenograft mouse model with UBXN11 overexpression were established to investigate the pathological role of UBXN11 in CRC progression. Luciferase assay, qPCR, and Western blot were performed to dissect the interaction between UBXN11 and NF-κB signaling.

RESULTS

Heightened UBXN11 expression was observed in various digestive tract tumors, which was positively correlated with the reduced overall survival rates in CRC patients. Overexpression of UBXN11 significantly enhanced CRC cell proliferation in vitro and promoted tumor growth in vivo. Mechanistically, UBXN11 promoted CRC tumorigenesis through increasing the activation of NF-κB signaling pathway.

CONCLUSIONS

This study underscores the pivotal role of UBXN11 in CRC progression and paves the way for novel therapeutic strategies for CRC treatment.

Heterogeneous Uptake of 68 Ga-DOTATATE and 18 F-FDG in Initial Diagnosed Neuroendocrine Tumors Patients : Which Patients Are Suitable for Dual-Tracer PET Imaging?

PURPOSE

This study was designed to assess the uptake heterogeneity in neuroendocrine tumor (NET) patients at initial diagnosis with dual-tracer PET imaging and the staging changes and prognostic value it brings to explore the indication of the use of dual-tracer PET.

METHODS

Fifty-one newly diagnosed patients with pathologically confirmed NET who underwent 18 F-FDG and 68 Ga-DOTATATE PET imaging between January 2020 and September 2022 were enrolled. Dual-tracer uptake patterns were classified into 3 groups: A. 68 Ga-DOTATATE positive and 18 F-FDG negative, B. 68 Ga-DOTATATE positive and 18 F-FDG positive, and C. 68 Ga-DOTATATE negative and 18 F-FDG positive. Descriptive statistics were used to evaluate the heterogeneity of dual-tracer uptake patterns among different grading (G) groups, between primary and metastatic lesions, and staging changes. Moreover, dual-tracer uptake patterns, grade, age, sex, and stage were compared with progression-free survival (PFS) by Cox regression.

RESULTS

In the different G groups, none of the patients with dual-tracer uptake pattern A had grade 3 histology, but 57% of patients with grade 1 disease had FDG avidity (25% of them resulting in dual-tracer uptake pattern C). Patients with no metastasis were well differentiated, but one of them presented with dual-tracer uptake pattern C. Different uptake patterns were also observed between primary and metastatic lesions, particularly 44% of patients with dual-tracer uptake pattern A of primary with FDG avidity of metastases. Moreover, 9 (17.6%) had new lesions detected by additional 18 F-FDG PET imaging, and 3 of them (5.9%) had clinical stage changed accordingly. The Cox regression test showed that the dual-tracer uptake patterns were significantly correlated with PFS by univariate and multivariate analyses ( P = 0.026 and 0.039, respectively), whereas the grade and stage did not correlate with survival (all P >0.05).

CONCLUSION

The current study has proven the uptake heterogeneity of the NET at initial diagnosis and demonstrated the staging and prognostic value of dual-tracer PET imaging. Our preliminary results have confirmed the importance of dual-tracer imaging modalities and concluded that dual-tracer PET imaging could be considered as prognostic tool for all patients with an initial diagnosis of NET.

Mixed neuroendocrine-non-neuroendocrine neoplasm of the bile duct with long-term prognosis after neoadjuvant chemotherapy

A 74-year-old man with obstructive jaundice presented with a thickened distal bile duct wall. A transpapillary forceps biopsy revealed an adenocarcinoma; however, because the tumor image was different from that of a typical cholangiocarcinoma, endoscopic ultrasound-guided fine-needle aspiration was performed on the tumor and enlarged lymph nodes. The tumor cells were positive for synaptophysin and CD56 with a Ki67 labeling index of 95%, and he was diagnosed with small cell neuroendocrine carcinoma. We diagnosed a bile duct tumor with neuroendocrine carcinoma component with lymph node metastasis. Preoperative chemotherapy for neuroendocrine carcinoma was administered because R0 resection was difficult and the risk of postoperative recurrence was high. Three courses of chemotherapy with carboplatin and etoposide resulted in marked tumor shrinkage, and radical resection was performed 3 months after diagnosis. Postoperative pathology revealed adenocarcinoma in the mucosal epithelium and small cell neuroendocrine carcinoma in the submucosa, most of which resolved with chemotherapy. Carboplatin and etoposide were resumed as adjuvant chemotherapy, and 67 months of recurrence-free survival were achieved after surgery.

Prevalence of, Subtypes of, and the Role of Age in Incidental Appendiceal Neoplasms in Acute Appendicitis: A Single-Institute Study from Bahrain

INTRODUCTION

Primary appendiceal neoplasms (ANs) are rare entities that can present with acute appendicitis symptoms. Accurate diagnosis of these diverse subtypes is crucial for prognosis and proper management.

AIMS AND OBJECTIVES

 This descriptive retrospective study aims to determine the prevalence and pathological subtypes of incidental ANs in patients presenting with acute appendicitis symptoms at Salmaniya Medical Center (SMC) in Bahrain between the period of January 2020 and March 2024. Particular focus was placed on investigating whether advanced age is a significant risk factor for these neoplasms.

MATERIALS AND METHODS

 The study included 38,643 patients (aged 15 years and above) who underwent appendectomy for suspected acute appendicitis during the study period. Demographic data, clinical diagnoses, preoperative imaging findings, histopathological reports, and management details were analyzed. Medical records of patients were retrieved from ISEHA system. Statistical analysis was done using Microsoft Excel.

RESULTS

The results showed that 12 patients (0.04% per year) had different subtypes of appendiceal tumors. Neuroendocrine tumors were the most common, identified in nine patients (75%), including nine cases of well-differentiated neuroendocrine carcinoma (NEC). Other histopathological subtypes included low-grade appendiceal mucinous neoplasm (LAMN), adenocarcinoma, and goblet cell adenocarcinoma, each found in one patient. Additionally, two patients had confirmed appendiceal mucocele. The mean age of patients with ANs was 30 years (range: 19-52 years), and 66.6% were younger than 38 years.  Conclusion: These findings highlight the importance of considering ANs in the differential diagnosis of acute appendicitis, especially in older patients. Further research is warranted to confirm the role of age as a risk factor and guide clinical decision-making.

Claudin 18.2 expression in digestive neuroendocrine neoplasms: a clinicopathological study

BACKGROUND

Claudin 18.2-targeted therapy has shown significant efficacy in treating claudin 18.2-positive cancers. However, limited systematic studies have investigated characteristics of claudin 18.2 expression in neuroendocrine neoplasms (NENs).

METHODS

Data and specimens from 403 cases of digestive NENs were retrospectively collected, and claudin 18.2 expression was detected using immunochemical staining.

RESULTS

Claudin 18.2 was positive in 19.6% (79/403) of the digestive NENs. The highest positive rate of claudin 18.2 was observed in gastric NENs (72/259, 27.8%), accounting for 91.1% (72/79) of all positive cases. The positivity rate was significantly higher in gastric NENs compared to pancreatic (2/78, 2.6%) or colorectal NENs (2/38, 5.3%; p < 0.05). For digestive NENs, claudin 18.2 positivity was significantly higher in neuroendocrine carcinomas (NECs) (37/144, 25.7%) than in neuroendocrine tumours (NETs; 14/160, 8.8%; p < 0.001), but no significant difference was found between gastric NECs (59/213, 27.7%) and gastric NETs (13/46, 28.3%; p > 0.05). The positivity was significantly higher in large-cell NECs (LCNECs; 28/79, 35.4%) and MiNEN (mixed neuroendocrine-non- neuroendocrine neoplasms)-LCNECs (23/66, 34.8%) compared to small-cell NECs (SCNECs; 9/65, 13.8%) and MiNEN-SCNECs (5/33, 15.2%; p < 0.05). Claudin 18.2 expression was more prevalent in gastric NENs than in pancreatic (12.5 ×; p = 0.001) and colorectal NENs (5.9 ×; p = 0.021). Claudin 18.2 staining was a useful method for identify the gastric origins of NETs, with a sensitivity of 28.3% and a specificity of 99.1%.

CONCLUSION

The expression characteristics of claudin 18.2 in NENs were characterized, which may provide a clinicopathological reference for targeted therapies in patients with NENs.

Impact of grade on workup of rectal neuroendocrine tumors: a retrospective cohort study : Grade impact on workup of rectal NETs

BACKGROUND

Rectal neuroendocrine tumors (RNETs) are often discovered on screening colonoscopy. Indications for staging and definitive resection are inconsistent in current guidelines. We evaluated the role of grade in guiding staging and procedural decision-making.

METHODS

Patients with biopsy confirmed RNETs between 2004 and 2015 were reviewed. Baseline characteristics, staging investigations (biochemical and imaging), and endoscopic/surgical treatment were recorded. Associations between grade, preoperative staging, interventions, and survival were determined using Fisher-Freeman-Halton Exact, log-rank, and Kaplan-Meier analysis.

RESULTS

Amongst 139 patients with RNETs, 9% were aged ≥ 75 years and 44% female. Tumor grade was: 73% grade 1 (G1), 18%, grade 2 (G2) and 9% grade 3 (G3). Staging investigations were performed in 52% of patients. All serum chromogranin A and 97% of 24-hour urine 5-hydroxyindoleacetic acid tests were normal. The large majority of staging computed tomography (CT) scans were negative (76%) with subgroup analysis showing no G1 patients with CT identified distant disease compared with 38% of G2 and 50% of G3 patients (p < 0.001). G1 patients were more likely to achieve R0/R1 resections compared to G2 (95% vs. 50%, p < 0.001) and G1 patients had significantly better 5-year overall survival (G1: 98%, G2: 67%, G3: 10%, p < 0.001).

CONCLUSION

Tumor grade is important in preoperative workup and surgical decision-making. Biochemical staging may be omitted but staging CT should be considered for patients with grade ≥ 2 lesions. Anatomic resections should be considered for patients with grade 2 disease.

Gastric mixed neuroendocrine non-neuroendocrine neoplasms

The uncommon tumour known as gastric mixed neuroendocrine-non-neuroendocrine neoplasms (G-MiNENs) is made up of parts of neuroendocrine carcinoma and adenocarcinoma. The biological and clinical features are different from those of gastric adenocarcinoma. Their pathophysiology, diagnostic standards, and clinical behaviour have all been the subject of lengthy debates, and their nomenclature has undergone multiple changes. Its emergence has created new challenges in the classification and diagnosis of gastric tumours. This review will update information on the topic, covering molecular aspects, diagnostic criteria, treatment, and prognostic factor discovery. It will also provide a historical context that will aid in understanding the evolution of the idea and nomenclature of mixed gastric tumours. Additionally, it will provide the reader a thorough understanding of this difficult topic of cancer that is applicable to real-world situations.

Managing end-stage carcinoid heart disease: A case report and literature review

BACKGROUND

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are rare tumors, often diagnosed in an advanced stage when curative treatment is impossible and grueling symptoms related to vasoactive substance release by tumor cells affect patients' quality of life. Cardiovascular complications of GEP-NENs, primarily tricuspid and pulmonary valve disease, and right-sided heart failure, are the leading cause of death, even compared to metastatic disease.

CASE SUMMARY

We present a case of a 35-year-old patient with progressive dyspnea, back pain, polyneuropathic leg pain, and nocturnal diarrhea lasting for a decade before the diagnosis of neuroendocrine carcinoma of unknown primary with extensive liver metastases. During the initial presentation, serum biomarkers were not evaluated, and the patient received five cycles of doxorubicin, which he did not tolerate well, so he refused further therapy and was lost to follow-up. After 10 years, he presented to the emergency room with signs and symptoms of right-sided heart failure. Panneuroendocrine markers, serum chromogranin A, and urinary 5-hydroxyindoleacetic acid were extremely elevated (900 ng/mL and 2178 µmol/L), and transabdominal ultrasound confirmed hepatic metastases. Computed tomography (CT) showed liver metastases up to 6 cm in diameter and metastases in mesenteric lymph nodes and pelvis. Furthermore, an Octreoscan showed lesions in the heart, thoracic spine, duodenum, and ascendent colon. A standard transthoracic echocardiogram confirmed findings of carcinoid heart disease. The patient was not a candidate for valve replacement. He started octreotide acetate treatment, and the dose escalated to 80 mg IM monthly. Although biochemical response and symptomatic improvement were noted, the patient died.

CONCLUSION

Carcinoid heart disease occurs with carcinoid syndrome related to advanced neuroendocrine tumors, usually with liver metastases, which manifests as right-sided heart valve dysfunction leading to right-sided heart failure. Carcinoid heart disease and tumor burden are major prognostic factors of poor survival. Therefore, they must be actively sought by available biochemical markers and imaging techniques. Moreover, imaging techniques aiding tumor detection and staging, somatostatin receptor positron emission tomography/CT, and CT or magnetic resonance imaging, should be performed at the time of diagnosis and in 3- to 6-mo intervals to determine tumor growth rate and assess the possibility of locoregional therapy and/or palliative surgery. Valve replacement at the onset of symptoms or right ventricular dysfunction may be considered, while any delay can worsen right-sided ventricular failure.

Case report: A rare case of coexistence of low-grade appendiceal mucinous neoplasia and goblet cell adenocarcinoma in the appendix

Background

Primary appendiceal tumors are rare. Low-grade appendiceal mucinous neoplasia (LAMN) and goblet cell adenocarcinoma (GCA) account for 20% and 14% of primary appendiceal tumors, respectively. The coexistence of LAMN and GCA is an extremely rare event. This report presents a case of an elderly male patient with an appendiceal tumor composed of LAMN and GCA in the same appendix.

Case presentation

A 72-year-old male patient was admitted to our institution presenting with a history of abdominal pain localized to the right lower quadrant for two months. Abdominal computed tomography (CT) showed a large dilated thickened cystic mass in the appendix, along with a small duodenal diverticulum. Laboratory tests indicated elevated levels of serum carcinoembryonic antigen (CEA) and cancer antigen 199 (CA19-9) markers. The patient underwent a laparoscopic right hemicolectomy and exploration of the duodenal diverticulum, and there was no finding of perforation of the duodenal diverticulum. Focal positivity for chromogranin A (CgA) and synaptophysin (Syn) was observed in the tumor cells of GCA. The final pathological diagnosis revealed the coexistence of LAMN staged pT4a and grade 1 GCA staged pT3 in the appendix. Unfortunately, the patient died due to severe septic shock and circulatory failure secondary to a perforated duodenal diverticulum.

Conclusions

The coexistence of LAMN and GCA are extremely rare in the appendix and may result from the proliferation of two independent cellular lines. The coexistence of distinct neoplasms poses diagnostic and management challenges. Multidisciplinary team discussion may be essential in the effective management of these patients.

Small Cell Carcinoma of the Rectum Associated With a Tubulovillous Adenoma: An Atypical Case Presentation

Small cell carcinoma of the rectum (SCCR) is a rare and aggressive neuroendocrine tumor. Its association with a tubulovillous adenoma is an exceptional occurrence, presenting significant implications for diagnosis and treatment. This case report details a 62-year-old male, undergoing treatment for hepatocellular carcinoma, presented with symptoms of diarrhea. A colonoscopy initially suggested a benign tubulovillous adenoma, but the presence of discordant clinical findings led to further evaluation. The final diagnosis, established post-surgery, was SCCR originating from a tubulovillous adenoma. This case highlights the diagnostic challenges when unusual presentations arise from atypical pathological findings, especially in patients with concurrent malignancies. The management followed standard care protocols, including robotic transanal surgery, despite the patient's ongoing HCC treatment. This case adds to the limited existing literature on SCCR, particularly its rare association with a tubulovillous adenoma. It emphasizes the importance of a multi-disciplinary approach in diagnosing and managing rare entities in colorectal cancer while demonstrating the feasibility of standard care in patients with complex comorbidities.

Sporadic Zollinger-Ellison syndrome in a patient with isolated mesenteric gastrinoma

INTRODUCTION

Zollinger-Ellison syndrome (ZES) is due to a gastrin-producing neuroendocrine tumor (gastrinoma) with subsequent gastric acid hypersecretion, gastroesophageal reflux disease (GERD), peptic ulcers, and chronic diarrhea.

CASE PRESENTATION

A 40-year old patient presented with epigastric pain associated with diarrhea evolving for 10 years, he has been treated by acid-suppressive medications without substantial clinical improvement. Gastro-duodenal endoscopy was performed with gastric biopsies that showed peptic ulcerations, a serum gastrin assay that showed high levels exceeding 10 times the upper limit of the normal range. The abdominal contrast-enhanced computed tomography scan (CT-Scan) showed a solid-cystic mass with contrast enhancement in the right colon mesentery. The histopathological analysis of the resected mass showed a well-differentiated neuroendocrine tumor, and the diagnosis of a sporadic Zollinger-Ellison syndrome (ZES) was disclosed. Eighteen months after the surgical treatment the patient has no symptoms of the disease.

CLINICAL DISCUSSION

Patients with ZES present often with long-standing clinical symptoms with delayed diagnosis. The surgical resection of the causative gastrinoma remains the most effective therapeutic treatment.

CONCLUSION

Patients with refractory chronic diarrhea and epigastric pain should be suspected of having ZES in order to benefit from adequate clinical management.

Current Status of Treatment among Patients with Appendiceal Tumors-Old Challenges and New Solutions?

The 5th edition of the World Health Organization (WHO) classification of tumors of the digestive system distinguishes four categories of appendiceal tumors (ATs): serrated lesions and polyps, mucinous neoplasms, adenocarcinomas, and neuroendocrine neoplasms (NENs). The differential diagnosis of ATs can be challenging in medical practice, due to their rarity and lack of data from randomized controlled trials on a large, diverse group of patients. ATs are usually noted in specimens obtained during appendectomies due to clinical acute appendicitis. In the European population, most ATs (65%) occur over the age of 50 and among women (56.8%). According to histological type, 54.6% are neuroendocrine tumors (NETs); 26.8% cystic, mucinous, and serous neoplasms; and 18.6% adenocarcinoma not otherwise specified (NOS). On pathologic analysis, most AT findings are benign lesions or small NENs that do not require further therapeutic measures. The presence of appendiceal mucinous neoplasm (AMN) can lead to pseudomyxoma peritonei (PMP). While the multimodal treatment for abdominal malignancies has evolved over the past several decades, the clinical workup and treatment of ATs remain a challenge. Therefore, this review aims to describe the diagnostic possibilities, molecular-based diagnosis, staging, differences in the treatment process, and prognostic factors associated with ATs.

Improving susceptibility of neuroendocrine tumors to radionuclide therapies: personalized approaches towards complementary treatments

Radionuclide therapies are an important tool for the management of patients with neuroendocrine neoplasms (NENs). Especially [131I]MIBG and [177Lu]Lu-DOTA-TATE are routinely used for the treatment of a subset of NENs, including pheochromocytomas, paragangliomas and gastroenteropancreatic tumors. Some patients suffering from other forms of NENs, such as medullary thyroid carcinoma or neuroblastoma, were shown to respond to radionuclide therapy; however, no general recommendations exist. Although [131I]MIBG and [177Lu]Lu-DOTA-TATE can delay disease progression and improve quality of life, complete remissions are achieved rarely. Hence, better individually tailored combination regimes are required. This review summarizes currently applied radionuclide therapies in the context of NENs and informs about recent advances in the development of theranostic agents that might enable targeting subgroups of NENs that previously did not respond to [131I]MIBG or [177Lu]Lu-DOTA-TATE. Moreover, molecular pathways involved in NEN tumorigenesis and progression that mediate features of radioresistance and are particularly related to the stemness of cancer cells are discussed. Pharmacological inhibition of such pathways might result in radiosensitization or general complementary antitumor effects in patients with certain genetic, transcriptomic, or metabolic characteristics. Finally, we provide an overview of approved targeted agents that might be beneficial in combination with radionuclide therapies in the context of a personalized molecular profiling approach.

Recurrence-Free Survival and Disease-Specific Survival in Patients with Pancreatic Neuroendocrine Neoplasms: A Single-Center Retrospective Study of 413 Patients

INTRODUCTION

The prognosis and impact of different prognostic factors in pancreatic neuroendocrine neoplasms (pNEN) remain controversial.

AIM

To investigate prognostic factors for recurrence-free survival and disease-specific survival in patients with pNEN, divided into three groups: patients undergoing surveillance (tumor size < 2 cm, group 1), patients followed after curative-intended surgery (group 2), and patients with unresectable disease or residual tumors after resection (group 3).

METHOD

A single-center retrospective study including consecutive patients over a 20-year period. Multivariate Cox regression analyses were performed to identify risk factors.

RESULTS

413 patients were included, with a mean (SD) age of 62 ± 14 years. In group 1 (n = 51), median (IQR) follow-up was 29 (21-34) months, and tumor size was 1.0 (0.8-1.4) cm. One progressed and had a tumor resection. In group 2 (n = 165), follow-up 59 (31-102) months, median tumor size 2 (1.2-3.4) cm, median Ki-67 index 5 (3-10)%, the 5-year recurrence rate was 21%. Tumor size (p < 0.001), Ki-67 index (p = 0.02), and location in the pancreatic head (p < 0.001) were independent risk factors. In group 3 (n = 197), follow-up 19 (6-46) months, median tumor size 4.2 (2.6-7.0) cm, Ki-67 index 17 (9-64)%, the median disease-specific survival was 22 (6-75) months-99 in NET G1; 54 in NET G2; 14 in NET G3; and 6 months in neuroendocrine carcinomas (NEC). Age (p = 0.029), plasma chromogranin A (p = 0.014), and proliferation, expressed by grade (p = 0.001) and Ki-67 index (p < 0.001), were risk factors.

CONCLUSION

Growth in pNET < 2 cm requiring surgery was observed in 1/51. Tumor size, Ki-67 index, and location in the head were prognostic factors for disease recurrence, while age, plasma chromogranin A, and proliferation predicted mortality in patients with unresectable disease or residual tumors after resection.

Prioritization of Fluorescence In Situ Hybridization (FISH) Probes for Differentiating Primary Sites of Neuroendocrine Tumors with Machine Learning

Determining neuroendocrine tumor (NET) primary sites is pivotal for patient care as pancreatic NETs (pNETs) and small bowel NETs (sbNETs) have distinct treatment approaches. The diagnostic power and prioritization of fluorescence in situ hybridization (FISH) assay biomarkers for establishing primary sites has not been thoroughly investigated using machine learning (ML) techniques. We trained ML models on FISH assay metrics from 85 sbNET and 59 pNET samples for primary site prediction. Exploring multiple methods for imputing missing data, the impute-by-median dataset coupled with a support vector machine model achieved the highest classification accuracy of 93.1% on a held-out test set, with the top importance variables originating from the ERBB2 FISH probe. Due to the greater interpretability of decision tree (DT) models, we fit DT models to ten dataset splits, achieving optimal performance with k-nearest neighbor (KNN) imputed data and a transformation to single categorical biomarker probe variables, with a mean accuracy of 81.4%, on held-out test sets. ERBB2 and MET variables ranked as top-performing features in 9 of 10 DT models and the full dataset model. These findings offer probabilistic guidance for FISH testing, emphasizing the prioritization of the ERBB2, SMAD4, and CDKN2A FISH probes in diagnosing NET primary sites.

Incidence and Management of Appendiceal Neuroendocrine Tumors in Pediatric Population: A Bicentric Experience with 6285 Appendectomies

BACKGROUND

Neuroendocrine tumors (NETs) are rare tumors that arise from neuroendocrine cells and are the most common tumors of the appendix. NETs of the appendix usually cause no symptoms and often go unnoticed until they cause acute appendicitis or are discovered during an accidental appendectomy. As the trend towards the conservative treatment of acute appendicitis increases in the pediatric population, the question arises as to whether the majority of NETs go undetected and are only discovered at an advanced stage. The purpose of the proposed study is to review the incidence and outcomes of treatment for NETs of the appendix in children and include the data presented in the data pool for further review.

METHODS

From 1 January 2009 to 1 November 2023, a total of 6285 appendectomies were performed in two large pediatric centers in Croatia. After a retrospective review of the case records and histopathologic findings, a total of 31 children (0.49%) were diagnosed with NET of the appendix and included in the further analysis. The primary outcome of this study was the incidence and treatment outcome of pediatric patients diagnosed with NET of the appendix. Secondary outcomes included the patients' demographic, clinical, and laboratory data and the histopathologic characteristics of tumor species.

RESULTS

The overall incidence of NETs of the appendix was stable over the study years, with minor fluctuations. The median age of patients was 14 (interquartile range-IQR: 12, 16) years, with a female predominance (64.5%). The majority of patients (96.8%) presented with acute abdominal pain and underwent appendectomy because acute appendicitis was suspected. Acute appendicitis was confirmed by histopathology in 18 (58%) cases. NETs of the appendix were not detected preoperatively in any of the patients. Among patients with confirmed acute appendicitis, most (n = 14; 77.8%) were found to have non-perforated acute appendicitis. In most children, the tumor was located at the tip of the appendix (n = 18; 58.1%), and the majority of tumors had a diameter of less than 1 cm (n = 21, 67.7%). The mitotic count (n = 25, 80.6%) and Ki-67 proliferation index (n = 23, 74.2%) were low in most patients, so most tumors were classified as NET G1 (n = 25, 80.6%), while NET G2 and NET G3 were found in four (12.9%) and two (6.5%) patients, respectively. All children were treated with appendectomy only. The median follow-up time was 54 (IQR: 24, 95) months.

CONCLUSIONS

The incidence of appendiceal NET among pediatric patients is very low. NET occurs most frequently in adolescents, with a female predominance. Most tumors are less than 1 cm in diameter, located at the tip, and associated with non-perforated appendicitis. Appendectomy is the treatment of choice, and major surgery was not necessary in our cohort.

Comparison of the clinical features and long-term prognosis of gallbladder neuroendocrine carcinoma versus gallbladder adenocarcinoma: A propensity score-matched analysis

Gallbladder neuroendocrine carcinoma (GBNEC) is rare and characterized by a low degree of tumor differentiation. The clinical features of GBNEC versus gallbladder adenocarcinoma (GBADC) remain a subject of debate. A total of 201 GBADC and 36 GBNEC cases that underwent surgery resection between January 2010 and 2022 at the Department of Biliary Surgery, West China Hospital, Sichuan University were included. A 1:1 propensity score matching (PSM) was performed based on seven predefined variables: age, sex, the American Joint Committee on Cancer (AJCC) stage, resection status, perineural invasion (PNI), lymphovascular invasion (LVI), and degree of tumor differentiation. Compared with GBADC, GBNEC patients were younger (median age 56.0 vs 64.0 years; P = 0.001), and more patients presented with advanced stages of tumor (P = 0.003). Patients with GBNEC also had a higher rate of PNI (55.6% vs 22.4%; P < 0.001), and LVI (63.9% vs 45.80%; P = 0.658). Before PSM, GBNEC patients had inferior prognoses compared with GBADC patients with a shorter median overall survival (mOS) (15.02 vs 20.11 months; P = 0.0028) and a shorter median recurrence-free survival (mRFS) (10.30 vs 15.17 months; P = 0.0028). However, after PSM analyses, there were no differences in OS (mOS 18.6 vs 18.0 months; P=0.24) or RFS (mRFS 10.98 vs 12.02 months; P = 0.39) between the GBNEC and GBADC cases. After multivariate analysis, tumor diagnosis (GBNEC vs GBADC) was not identified as an independent risk factor for shorter RFS (P = 0.506) or OS (P = 0.731). Unfavorable pathological features, including advanced AJCC tumor stages, poor differentiation, presence of LVI, and positive resection margins (all P < 0.05), were independent risk factors for inferior OS and RFS. GBNEC is difficult to diagnose early and has a prognosis comparable to stage-matched poorly differentiated GBADC. Tumor diagnosis (either GBADC or GBNEC) was not an independent risk factor for the patient's OS. Unfavorable pathological features of the neoplasm are the main determinants.

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.

Clinicopathologic and Molecular Characterization of Anorectal Neuroendocrine Carcinomas Reveals Human Papillomavirus, p53, and c-Myc as Alternative Mechanisms of Carcinogenesis

Poorly differentiated neuroendocrine carcinomas (NECs) are rare malignant neoplasms with aggressive behavior. The diagnosis remains challenging due to ever-changing terminologies and morphologic overlaps with other disease entities. Herein, we seek to better define anorectal NECs by high-risk human papillomavirus (HPV) status and molecular profiling. Fourteen cases, including 3 men and 11 women with a median age of 63 years, were included. High-risk HPV RNA in situ hybridization was diffusely positive (+) in 7 cases, focal rarely positive (+/-) in 2 cases, and completely negative (-) in 5 cases. By morphology, all HPV(-) NECs were large-cell type, 3 mixed with a tubular adenoma/dysplasia or invasive adenocarcinoma. HPV-related (+ or +/-) NECs were mostly small-cell type, 3 mixed with squamous dysplasia and/or squamous cell carcinoma. Immunohistochemically, all NECs were positive for at least 2 neuroendocrine markers. The HPV(-) NECs were also positive for CDX2, whereas all HPV-related NECs were negative or only focally positive for CDX2, p40, and p63. Overexpression of p53 was found in 3 HPV(-) and 2 HPV(+/-) NECs but not in any HPV(+) NECs. Molecular analysis revealed MYC gene amplification in 4 cases: 2 HPV(-), 1 HPV(+/-), and 1 HPV(+). This was confirmed by fluorescence in situ hybridization in all but 1 HPV(-) NEC, which showed polysomy 8 but no true MYC amplification. Interestingly, only 2 of the 4 MYC amplification-bearing cases, both p53 normal/wild-type, expressed c-Myc protein by immunohistochemistry. The other 2 cases, both p53 overexpressed, did not show c-Myc expression despite true MYC amplification. Our study demonstrates that anorectal NECs arise in HPV-dependent or -independent pathways, with heterogeneous expression of other lineage markers and different molecular signatures. Expressions of p53 and c-Myc proteins appear to be mutually exclusive regardless of HPV status, likely mediating alternative mechanisms of NEC carcinogenesis.

High Incidence of Appendiceal Neoplasms in the Elderly: A Critical Concern for Non-Surgical Treatment

OBJECTIVE

Appendiceal neoplasms (ANs) are rare tumors that are often discovered incidentally during histopathological examinations. The increasing incidence of ANs is a critical issue in the non-operative management of acute appendicitis. This study aimed to document the temporal trends over a 12-year period by analyzing the clinical presentation, imaging findings, and histopathological features of ANs.

SUBJECTS AND METHODS

Health records of patients who underwent appendectomy from 2011 to 2022 were examined. Demographic and clinical data, laboratory results, imaging findings, and histopathological features were documented. The characteristics of both ANs and non-neoplastic cases were evaluated.

RESULTS

A total of 22,304 cases were identified, of which 330 (1.5%) were diagnosed with ANs. The odds ratio for ANs increased with age, with the highest odds ratio observed in patients aged 70 or older. Receiver Operating Characteristic analysis showed that age and appendiceal diameter were significant predictors of ANs. An optimal age cut-off point of 28.5 years was determined, yielding a sensitivity of 72% and a specificity of 64%. For appendiceal diameter, the optimal cut-off was found to be 9.5 mm, exhibiting a sensitivity of 77% and a specificity of 56%.

CONCLUSION

Although the incidence of ANs remains relatively low, a steady increase has been observed over the past decade. The increasing rate of ANs raises concerns regarding non-surgical management options. The results of this study highlight the importance of considering ANs as a potential diagnosis in older patients and in patients with an appendix diameter greater than 9.5 mm. These findings may have implications for treatment and management.

Multivisceral resection of nonfunctional pancreatic neuroendocrine neoplasm with nearby organ invasion: a case report

Pancreatic neuroendocrine neoplasms (pNENs) are relatively rare epithelial malignancies originating from pancreatic neuroendocrine cells, pathologically classified into well-differentiated pancreatic neuroendocrine tumors (pNETs) and poorly-differentiated pancreatic neuroendocrine carcinoma (pNECs). Although they also fall under the category of pNENs, the almost entirely distinct biological characteristics and survival prognosis have caused debate among surgeons when it comes to the development of surgical intervention options, particularly for locally advanced G3 pNETs and pNECs. We present a case of 66-year-old male with nonfunctional G3 pNET, invasion of five nearby pancreatic organs and type II liver metastases. The patient achieved good outcomes after undergoing multivisceral resection and postoperative adjuvant chemotherapy. This finding helps surgeons better understand locally advanced pNENs, formulate treatment decisions systematically and confidently, and balance patient benefits and risks of surgery.

Three Dimensional Models of Endocrine Organs and Target Tissues Regulated by the Endocrine System

Immortalized cell lines originating from tumors and cultured in monolayers in vitro display consistent behavior and response, and generate reproducible results across laboratories. However, for certain endpoints, these cell lines behave quite differently from the original solid tumors. Thereby, the homogeneity of immortalized cell lines and two-dimensionality of monolayer cultures deters from the development of new therapies and translatability of results to the more complex situation in vivo. Organoids originating from tissue biopsies and spheroids from cell lines mimic the heterogeneous and multidimensional characteristics of tumor cells in 3D structures in vitro. Thus, they have the advantage of recapitulating the more complex tissue architecture of solid tumors. In this review, we discuss recent efforts in basic and preclinical cancer research to establish methods to generate organoids/spheroids and living biobanks from endocrine tissues and target organs under endocrine control while striving to achieve solutions in personalized medicine.

Understanding the increasing incidence of neuroendocrine tumors

INTRODUCTION

Neuroendocrine tumors (NETs) are a diverse group of tumors with origins from different primary sites such as gastro-entero-pancreatic, lung and endocrine tissue. Worldwide, their incidence has increased in recent decades. Advances in imaging and better clinical awareness are traditionally attributed to this trend; however, other factors such as genetic and environmental contributors are appreciated as well.

AREAS COVERED

The purpose of this article is to review the worldwide epidemiologic trends in incidence of NET through the decades and discuss the various factors potentially contributing to the observed changes in incidence trends.

EXPERT OPINION

Overall, the incidence of NET has increased across the globe over the last few decades. Although multiple genetics and environmental factors have been proposed, the majority of this increase in incidence is secondary to earlier detection. Future studies will help in more accurate assessments and an improved understanding of disease incidence among patients with different grades and differentiation.

Potent molecular-targeted therapies for gastro-entero-pancreatic neuroendocrine carcinoma

Neuroendocrine neoplasms (NENs), which are characterized by neuroendocrine differentiation, can arise in various organs. NENs have been divided into well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs) based on morphological differentiation, each of which has a distinct etiology, molecular profile, and clinicopathological features. While the majority of NECs originate in the pulmonary organs, extrapulmonary NECs occur most predominantly in the gastro-entero-pancreatic (GEP) system. Although platinum-based chemotherapy is the main therapeutic option for recurrent or metastatic GEP-NEC patients, the clinical benefits are limited and associated with a poor prognosis, indicating the clinically urgent need for effective therapeutic agents. The clinical development of molecular-targeted therapies has been hampered due to the rarity of GEP-NECs and the paucity of knowledge on their biology. In this review, we summarize the biology, current treatments, and molecular profiles of GEP-NECs based on the findings of pivotal comprehensive molecular analyses; we also highlight potent therapeutic targets for future precision medicine based on the most recent results of clinical trials.

Detection of Neuroendocrine Tumours by Enteroscopy: A Case Report

We present the case of a 62-year-old patient who developed melenas and in whom conventional endoscopic tests could not detect any bleeding lesion. In our case, capsule endoscopy and enteroscopy were the pivotal elements in establishing the diagnosis of a neuroendocrine tumour with an atypical location. As a result, it was possible to surgically remove the lesions at an early stage of the malignancy without metastatic disease and without the need for adjuvant therapy. Our case demonstrates the need for these new techniques in tumours of atypical location and aggressive course. Otherwise, this malignancy may be underdiagnosed until an advanced stage.

A rare occurrence of a poorly differentiated large cell neuroendocrine carcinoma of the gallbladder: A case report and review of the literature

INTRODUCTION

Neuroendocrine carcinoma (NEC) of the gallbladder is a rare entity with much of the surgical strategy and management mirroring that of adenocarcinoma of the gallbladder. In contrast to gallbladder adenocarcinoma, however, it tends to be a more aggressive and lethal malignancy associated with a short survival after the time of diagnosis. Furthermore, due to its rarity, there are no consensus guidelines for its management.

PRESENTATION OF CASE

We present the case of a 73-year-old female who presented with acute cholecystitis and was found to have a poorly differentiated large cell NEC of the gallbladder after laparoscopic cholecystectomy. She was treated with adjuvant chemotherapy and has shown no evidence of cancer recurrence on three-year follow up.

DISCUSSION

Surgical resection is the cornerstone of curative treatment for gallbladder NEC. Management may include simple cholecystectomy, extended cholecystectomy, radical cholecystectomy, or palliative cholecystectomy. It is unclear whether lymphadenectomy confers a survival benefit. Adjuvant chemotherapy with platinum-based regimens, on the other hand, has been associated with increased survival rates. Radiation, immunotherapy, somatostatin analogs and targeted therapy have also been used for treatment.

CONCLUSION

NEC of the gallbladder is extremely rare, aggressive, and carries a dismal prognosis. Further studies are needed to develop the optimal treatment approach to increase survival rates and establish best practices to manage these patients.

The Promise of Epigenetics Research in the Treatment of Appendiceal Neoplasms

Appendiceal cancers (AC) are a rare and heterogeneous group of malignancies. Historically, appendiceal neoplasms have been grouped with colorectal cancers (CRC), and treatment strategies have been modeled after CRC management guidelines due to their structural similarities and anatomical proximity. However, the two have marked differences in biological behavior and treatment response, and evidence suggests significant discrepancies in their respective genetic profiles. In addition, while the WHO classification for appendiceal cancers is currently based on traditional histopathological criteria, studies have demonstrated that histomorphology does not correlate with survival or treatment response in AC. Due to their rarity, appendiceal cancers have not been studied as extensively as other gastrointestinal cancers. However, their incidence has been increasing steadily over the past decade, making it crucial to identify new and more effective strategies for detection and treatment. Recent efforts to map and understand the molecular landscape of appendiceal cancers have unearthed a wealth of information that has made it evident that appendiceal cancers possess a unique molecular profile, distinct from other gastrointestinal cancers. This review focuses on the epigenetic landscape of epithelial appendiceal cancers and aims to provide a comprehensive overview of the current state of knowledge of epigenetic changes across different appendiceal cancer subtypes, highlighting the challenges as well as the promise of employing epigenetics in the quest for the detection of biomarkers, therapeutic targets, surveillance markers, and predictors of treatment response and survival in epithelial appendiceal neoplasms.

Analysis of surgical treatment of appendix neuroendocrine neoplasms-17 years of single-center experience

BACKGROUND/AIM

This study investigated the clinicopathological characteristics and treatment of appendix neuroendocrine neoplasms in appendectomy specimens of our center.

MATERIALS AND METHODS

The clinicopathological data, including age, sex, preoperative clinical manifestation, surgical method, and histopathological examination results of 11 patients with appendix neuroendocrine neoplasms confirmed by surgery and pathology between November 2005 and January 2023, were retrospectively analyzed.

RESULTS

In the histopathological examination of 7277 appendectomy specimens, 11 cases (0.2%) had appendix neuroendocrine neoplasms. Among the 11 patients, 8(72.7%) were males, and 3(27.3%) were females, with an average age of 48.1 years. All patients underwent emergency surgery. A total of 9 patients underwent open appendectomy, including 1 patient who underwent second-stage simple right hemicolectomy after an appendectomy, and two who underwent laparoscopic appendectomy. All 11 patients were followed up for a period of 1 to 17 years. All patients survived without any indication of tumor recurrence.

CONCLUSION

Appendiceal neuroendocrine neoplasms are low-grade malignant tumors originating from neuroendocrine cells. They are rarely seen in clinical practice and are often treated based on acute and chronic appendicitis symptoms. These tumors are challenging to diagnose before surgery due to the lack of specificity in clinical manifestations and auxiliary examinations. The diagnosis generally depends on postoperative pathology and immunohistochemistry. Despite the diagnostic challenges, these tumors have a favorable prognosis.

A case of neuroendocrine carcinoma with massive invasion to the liver and multiorgan causing acute liver failure

INTRODUCTION

Acute liver failure (ALF) due to a malignant neoplasm is rare. Here, we present a case of neuroendocrine carcinoma (NEC) with massive invasion to the liver and multi-organ causing ALF that resulted in a poor outcome. A 56-year-old man was referred to our hospital for ALF of unknown cause. Abdominal imaging studies revealed hepatomegaly with multiple intrahepatic lesions. The patient also showed disseminated intravascular coagulation. Despite administration of prednisolone for the ALF, he died suddenly of respiratory failure on day 3 after admission. Autopsy showed a markedly enlarged liver weighing 4,600 g with diffuse nodular lesions. The tumors had metastasized to the lungs, spleen, adrenal glands, and bone marrow. Severe pulmonary hemorrhage was also noted. Histologically, the tumors were poorly differentiated and composed of small-sized and uniform neoplastic cells, positive for chromogranin A, synaptophysin, CD56, and p53 with a Ki-67 labeling index of over 50%. As there was no primary lesion in the gastrointestinal tract, pancreas, or other organs, primary hepatic neuroendocrine carcinoma (PHNEC) was suspected.

CONCLUSION

We experienced a case of NEC causing ALF and multi-organ invasion with a rapidly deteriorating course. Liver metastasis from a neuroendocrine tumor/neoplasm is common, while a primary hepatic neuroendocrine tumor/neoplasm is extremely rare. We could not determine PHNEC; however, it was highly suspected. Further studies are needed to elucidate the pathogenesis of this rare disease.

Neuroendocrine Neoplasms of the Gastrointestinal Tract versus Neuroendocrine Neoplasms of the Gynaecological Tract-Comparison of the Risk Factors and Non-Surgical Treatment Efficacy

Neuroendocrine tumours of the gastrointestinal tract are rare. The incidence has increased in recent years due to improvements in diagnostic methods for detecting these lesions. These tumours have a poor prognosis, especially when detected at an advanced stage. The basis of the treatment is resection, and non-surgical treatments are also standard in the treatment process. The situation is similar in even rarer neuroendocrine tumours of the reproductive tract, which are associated with an equally poor prognosis. In this article, we focus on learning about the risk factors (including genetic mutations) that increase the risk of the disease and comparing the effectiveness of non-surgical treatments-chemotherapy, radiotherapy, peptide receptor radionuclide therapy, somatostatin analogues, and immunotherapy. The efficacy of these treatments varies, and immunotherapy appears to be a promising form of treatment; however, this requires further research.

Neuroendocrine Neoplasms: Epidemiology, Diagnosis, and Management

Neuroendocrine tumors have variety of biological and clinical characteristics. The classification of neuroendocrine neoplasm has evolved, and the newest 2019 World Health Organization classification outlines a well-differentiated high-grade G3 subtype, recognizing its differences from the poorly differentiated neuroendocrine carcinoma. ⁶⁸Ga-DOTAT PET has largely replaced somatostatin scintigraphy as the diagnostic workup choice for NENs. NETest, a multi-analyte liquid biopsy, is a promising recent development in the biochemical diagnosis. Management includes wait and watch approach, surgical resection, somatostatin analogs, ¹⁷⁷Lu DOTATATE therapy, chemotherapy, radiotherapy or immunotherapy combinations. Further clinical trials are necessary for determining the appropriate sequencing.

Comparison of thoracoabdominal versus abdominal-transhiatal surgical approaches in Siewert type II adenocarcinoma at the esophagogastric junction: Protocol for a prospective multicenter randomized controlled trial

Background

Siewert type II adenocarcinoma of the esophagogastric junction (Siewert II AEG) can be resected by the right thoracoabdominal surgical approach (RTA) or abdominal-transhiatal surgical approach (TH) under minimally invasive conditions. Although both surgical methods achieve complete tumor resection, there is a debate as to whether the former method is superior to or at least noninferior to the latter in terms of surgical safety. Currently, a small number of retrospective studies have compared the two surgical approaches, with inconclusive results. As such, a prospective multicenter randomized controlled trial is necessary to validate the value of RTA (Ivor-Lewis) compared to TH.

Methods

The planned study is a prospective, multicenter, randomized clinical trial. Patients (n=212) with Siewert II AEG that could be resected by either of the above two surgical approaches will be included in this trial and randomized to the RTA group (n=106) or the TH group (n=106). The primary outcome will be 3-year disease-free survival (DFS). The secondary outcomes will include 5-year overall survival (OS), incidence of postoperative complications, postoperative mortality, local recurrence rate, number and location of removed lymph nodes, quality of life (QOL), surgical Apgar score, and duration of the operation. Follow-ups are scheduled every three months for the first 3 years after the surgery and every six months for the next 2 years.

Discussion

Among Siewert II AEG patients with resectable tumors, this is the first prospective, randomized clinical trial comparing the surgical safety of minimally invasive RTA and TH. RTA is hypothesized to provide better digestive tract reconstruction and dissection of mediastinal lymph nodes while maintaining a high quality of life and good postoperative outcome. Moreover, this trial will provide a high level of evidence for the choice of surgical procedures for Siewert II AEG.

Clinical trial registration

Chinese Ethics Committee of Registering Clinical Trials, identifier (ChiECRCT20210635); Clinical Trial.gov, identifier (NCT05356520).

Comparative Outcomes of Second-line Topoisomerase-I Inhibitor Therapies on Neuroendocrine Carcinoma

INTRODUCTION

This investigation aims to assess the outcomes for second-line therapies to treat extrapulmonary neuroendocrine carcinoma (EP-NEC) after first-line platinum-based chemotherapy.

METHODS

With IRB approval, we conducted a retrospective study of EP-NEC patients that progressed on first-line platinum chemotherapy from 2008 to 2018. Demographic data and treatment-related characteristics were collected and represented as descriptive statistics. The primary endpoints include overall survival (OS) and progression-free survival (PFS). OS and PFS were estimated and stratified by site of primary (gastroenteropancreatic [GEP] versus non-GEP) and type of second-line therapy (irino/topotecan versus others). Log-rank test and Kaplan-Meier curves were used to compare survival distributions between groups.

RESULTS

Forty-seven patients met eligibility, with median age 65 (range 31-82), 62% male, and 83% White; 22 were GEP and 25 were non-GEP primary. Thirty patients (63.8%) received second-line therapy where 11 received irinotecan/topotecan (ir/to), while 19 received other agents (temozolomide, other platinum agents, gemcitabine, paclitaxel, pembrolizumab, and sunitinib). The median OS was 10.3 months in the ir/to group versus 13.4 months for other therapies, p = 0.10. The median PFS for ir/to therapy compared to other therapies was 2.0 months versus 1.8 months, respectively, p = 0.72. The OS and PFS with and without ir/to were not significantly different by the primary site (p = 0.61 and p = 0.21).

DISCUSSION/CONCLUSION

Many EP-NEC patients undergo second-line therapies. Interestingly, outcomes for ir/to-containing second-line therapies were not statistically different from other agents, regardless of the site of primary. With approval of new second-line therapies for small cell lung cancer, further research in therapeutic options is needed for this aggressive disease.

All Together Now: Standardization of Nomenclature for Neuroendocrine Neoplasms across Multiple Organs

Neuroendocrine neoplasms (NENs) span virtually all organ systems and exhibit a broad spectrum of behavior, from indolent to highly aggressive. Historically, nomenclature and grading practices have varied widely across, and even within, organ systems. However, certain core features are recapitulated across anatomic sites, including characteristic morphology and the crucial role of proliferative activity in prognostication. A recent emphasis on unifying themes has driven an increasingly standardized approach to NEN classification, as delineated in the World Health Organization's Classification of Tumours series. Here, we review recent developments in NEN classification, with a focus on NENs of the pancreas and lungs.

What have we learnt from the past - would treatment decisions for GEP-NET patients differ between 2012 to 2016 by the new recommendations in 2022?

BACKGROUND

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a heterogeneous group of tumors with a broad range of local and systemic treatment options. Still a lack of data regarding treatment sequences exists. The aim of this study was to analyse outcomes in GEP-NETs depending on stage and treatment steps and compare our treatment decisions to the latest treatment recommendations of European Society of Medical Oncology (ESMO) 2020 for GEP-NETs.

METHODS

Patients were included in this retrospective single-center analysis from 2012-2016. All patients suffering from a GEP-NET, who were screened, treated or evaluated at ENETS Center in Zurich, Switzerland were included in analysis. Patients with any other diagnosis of NET were not included. We used Kaplan Meier estimator as well as Cox regression to compare survival rates between different sites of localization, grades or stages and treatment sequences.

RESULTS

Overall, we identified 256 GEP-NETs, most in advanced stage (62%) and located in small intestine tract or pancreatic gland. Survival depended on stage, grade, primary site and duration of response for the early systemic treatment. On average patients underwent 2.6 different treatment modalities, mostly depending on stage and higher tumor grade. Surgery was performed early but also in advanced stages, usually followed by Somatostatine-Agonist modalities. In distant disease (Stage IV), we investigated a positive effect of PFS after treatment with Somatostatine Analogues (SSA) (hazard ratio [HR], 0.45; 95% confidence interval [CI], 0.21 - 0.97; p = 0.04) and systemic treatment (HR, 0.51; 95% CI, 0.26 - 0.99; p = 0.047) if patients underwent prior surgery or endoscopic resection. Kaplan Meier distributions predict shorter OS in distant disease (Stage IV), (Figure. 1; HR, 2.06; 95% CI, 1.46 - 2.89; log-rank test, p < 0.001).

CONCLUSION

This retrospective analysis presents a great overview of all patients', disease and treatment characteristics of GEP-NETs at ENETS Center in Zurich, Switzerland. We illustrated survival (PFS) depending on implemented therapies. According to these findings, we formed a suggested treatment algorithm for advanced GEP-NETs, which does not differ from the latest treatment recommendation by ESMO guidelines for GEP-NETs. The results of this project may define GEP-NET patients' selection for upcoming clinical prospective studies.

Preoperative prediction of malignancy and surgical treatment strategy in appendiceal tumors: multicenter review of 51 consecutive cases

PURPOSE

A diagnostic and treatment strategy for appendiceal tumors (ATs) has not been established. We aimed to evaluate our treatment strategy in ATs, including laparoscopic surgery (LS), and to identify preoperative malignancy predictors.

METHODS

A total of 51 patients between 2011 and 2021 were retrospectively reviewed. Data, including tumor markers and imaging findings, were compared between carcinoma and non-carcinoma patients. Validity of planned operation was evaluated based on pathological diagnosis.

RESULTS

Twenty-five patients were diagnosed with carcinoma, 13 with low-grade mucinous neoplasm, and 13 with other diseases. Symptoms were more commonly present in carcinoma patients than in non-carcinoma patients (68.0% vs. 23.1%, p = 0.001). Elevated CEA and CA19-9 were more frequently observed in carcinoma patients than in non-carcinoma patients (p < 0.01 and p = 0.04, respectively). Five carcinoma patients had malignancy on biopsy, compared with zero non-carcinoma patients. Significant differences were noted in the percentages of carcinoma and non-carcinoma patients with solid enhanced mass (41.7% vs. 0%, p < 0.001) and tumor wall irregularity (16.7% vs. 0%, p = 0.03) on imaging. Although the sensitivity was not high, the specificity and positive predictive value of these findings were 100%. Forty-two patients (82.4%) underwent LS as minimally invasive exploratory and/or radical operation, of whom 2 were converted to open surgery for invasion of adjacent organ. No patients had intraoperative complications or postoperative mortality.

CONCLUSION

Clinical symptoms, elevated tumor markers, and worrisome features of solid enhanced mass and tumor wall irregularity on imaging can be malignancy predictors. For management of ATs, LS is feasible and useful for diagnosis and treatment.

The Complex Histopathological and Immunohistochemical Spectrum of Neuroendocrine Tumors-An Overview of the Latest Classifications

Neuroendocrine neoplasms (NENs) originate from the neuroendocrine cell system, which may either take the shape of organoid cell aggregations or be composed of dispersed cells across various organs. Therefore, these tumors are heterogenous regarding the site of origin, functional status, degree of aggressiveness, and prognosis. When treating patients with neuroendocrine tumors, one of the most significant challenges for physicians is determining the correct tumor grade and thus classifying patients into risk categories. Over the years, the classification of these tumors has changed significantly, often causing confusion due to clinical, molecular, and immunohistochemical variability. This review aims to outline the latest NENs classifications regardless of their site of origin. Thus, an overview of the key histopathological and immunohistochemical characteristics of NENs could pave the way to validate possible predictive and prognostic markers and also guide the therapeutic conduct.

The role of NLRP3 inflammasome in digestive system malignancy

Digestive system malignancies, the most common types of cancer and a major cause of death in the worldwide, are generally characterized by high morbidity, insidious symptoms and poor prognosis. NLRP3 inflammasome, the most studied inflammasome member, is considered to be crucial in tumorigenesis. In this paper, we reviewed its pro-tumorigenic and anti-tumorigenic properties in different types of digestive system malignancy depending on the types of cells, tissues and organs involved, which would provide promising avenue for exploring new anti-cancer therapies.

Immune Checkpoint Inhibitor Therapy in Neuroendocrine Tumors

Neuroendocrine tumors (NETs) occur in various regions of the body and present with complex clinical and biochemical phenotypes. The molecular underpinnings that give rise to such varied manifestations have not been completely deciphered. The management of neuroendocrine tumors (NETs) involves surgery, locoregional therapy, and/or systemic therapy. Several forms of systemic therapy, including platinum-based chemotherapy, temozolomide/capecitabine, tyrosine kinase inhibitors, mTOR inhibitors, and peptide receptor radionuclide therapy have been extensively studied and implemented in the treatment of NETs. However, the potential of immune checkpoint inhibitor (ICI) therapy as an option in the management of NETs has only recently garnered attention. Till date, it is not clear whether ICI therapy holds any distinctive advantage in terms of efficacy or safety when compared to other available systemic therapies for NETs. Identifying the characteristics of NETs that would make them (better) respond to ICIs has been challenging. This review provides a summary of the current evidence on the value of ICI therapy in the management of ICIs and discusses the potential areas for future research.

Primary testicular neuroendocrine tumor with liver lymph node metastasis: A case report and review of the literature

BACKGROUND

Primary testicular neuroendocrine tumors (TNETs) are sporadic, accounting for only 0.23% of all testicular tumors. Few cases have been reported in the literature, and no uniform treatment protocol exists. We report a case of a primary TNET with liver lymph node metastasis diagnosed at the age of 24 years and discuss its clinicopathological features, diagnosis, differential diagnosis, treatment, and prognosis.

CASE SUMMARY

We report the case of a 24-year-old patient with a primary TNET with liver lymph node metastasis. The patient was found to have a right testicular swelling of about 3 cm × 4 cm in size with unclear borders and no testicular pressure pain seven years ago without any examination or treatment. One month ago, an ultrasound examination was performed for persistent enlargement of the right testis, which showed an occupying lesion of the right testis approximately 110 mm × 102 mm × 82 mm in size. Magnetic resonance imaging scan of the testis (plain scan) showed that the right testis was an occupying lesion with inhomogeneous density and mixed signal, the boundary was still clear, and the possibility of seminoma was considered; chest X-ray and computed tomography did not show any apparent abnormalities. The patient underwent radical orchiectomy, and the pathological examination suggested a right TNET with a typical carcinoid tumor histological type. One month after the surgery, the patient received nine cycles of lanreotide chemotherapy at a dose of 90 mg/mo without adverse effects. No distant lymph node or other organ metastases were detected at follow-up. He is in good physical condition and attends regular follow-up visits.

CONCLUSION

Neuroendocrine tumors are rare in clinical practice, and the diagnosis mainly relies on the characteristics of microscopic tumor cells and immunohistochemical features. Treatment involves radical orchiectomy. If it is accompanied by distant lymph node metastasis and the metastatic lesion can be resected, it should be surgically removed; if it cannot be resected, growth inhibitor analog octreotide or lanreotide chemotherapy can be administered to obtain good results, with close postoperative follow-up to prevent recurrence and metastasis.

FAM83A promotes the progression and metastasis of human pancreatic neuroendocrine tumors by inducing the epithelial-mesenchymal transition via the PI3K/AKT and ERK pathways

PURPOSE

Family with sequence similarity 83, member A (FAM83A) has been reported to play an important role in cancer progression and metastasis. The purpose of this study was to clarify the role and mechanism of FAM83A in pancreatic neuroendocrine tumors (PanNETs).

METHODS

PanNET specimens and adjacent nontumor pancreatic tissues obtained from 68 patients who underwent curative surgery for PanNETs were assessed for FAM83A expression using immunochemical staining. The relationships between FAM83A expression, clinicopathological parameters and prognosis were statistically analyzed. PanNET cell lines were used to study the role of FAM83A in the progression and metastasis of PanNETs in vitro and in vivo.

RESULTS

FAM83A was overexpressed in PanNET specimens compared with adjacent nontumor tissues. Furthermore, FAM83A expression was closely associated with lymph node metastasis (P = 0.02), perineural invasion (P = 0.001), WHO classification (P = 0.039), AJCC stage (P = 0.01) and shorter disease-free survival in patients with PanNETs (P < 0.001). FAM83A overexpression effectively promoted PanNET cell proliferation, migration, invasion and growth both in vitro and in vivo, whereas FAM83A inhibition exerted the opposite effects. Subsequent mechanistic investigations revealed that FAM83A promotes the progression and metastasis of PanNETs by inducing epithelial-mesenchymal transition (EMT) via the PI3K/AKT and ERK pathways.

CONCLUSIONS

FAM83A plays an important role in the progression and metastasis of PanNET by inducing the EMT via the activation of the ERK and PI3K/AKT pathways and may serve as a valuable molecular target in PanNET treatment.

Artificial Intelligence-Powered Whole-Slide Image Analyzer Reveals a Distinctive Distribution of Tumor-Infiltrating Lymphocytes in Neuroendocrine Neoplasms

Despite the importance of tumor-infiltrating lymphocytes (TIL) and PD-L1 expression to the immune checkpoint inhibitor (ICI) response, a comprehensive assessment of these biomarkers has not yet been conducted in neuroendocrine neoplasm (NEN). We collected 218 NENs from multiple organs, including 190 low/intermediate-grade NENs and 28 high-grade NENs. TIL distribution was derived from Lunit SCOPE IO, an artificial intelligence (AI)-powered hematoxylin and eosin (H&E) analyzer, as developed from 17,849 whole slide images. The proportion of intra-tumoral TIL-high cases was significantly higher in high-grade NEN (75.0% vs. 46.3%, p = 0.008). The proportion of PD-L1 combined positive score (CPS) ≥ 1 case was higher in high-grade NEN (85.7% vs. 33.2%, p < 0.001). The PD-L1 CPS ≥ 1 group showed higher intra-tumoral, stromal, and combined TIL densities, compared to the CPS < 1 group (7.13 vs. 2.95, p < 0.001; 200.9 vs. 120.5, p < 0.001; 86.7 vs. 56.1, p = 0.004). A significant correlation was observed between TIL density and PD-L1 CPS (r = 0.37, p < 0.001 for intra-tumoral TIL; r = 0.24, p = 0.002 for stromal TIL and combined TIL). AI-powered TIL analysis reveals that intra-tumoral TIL density is significantly higher in high-grade NEN, and PD-L1 CPS has a positive correlation with TIL densities, thus showing its value as predictive biomarkers for ICI response in NEN.

Circulating Neuroendocrine Tumor Biomarkers: Past, Present and Future

Neuroendocrine tumors are a heterogeneous group of neoplasms originating from the diffuse endocrine system. Depending on primary location and hormonal status, they range in terms of clinical presentation, prognosis and treatment. Functional tumors often develop symptoms indicating an excess of hormones produced by the neoplasm (exempli gratia insulinoma, glucagonoma and VIPoma) and can be diagnosed using monoanalytes. For non-functional tumors (inactive or producing insignificant amounts of hormones), universal biomarkers have not been established. The matter remains an important unmet need in the field of neuroendocrine tumors. Substances researched over the years, such as chromogranin A and neuron-specific enolase, lack the desired sensitivity and specificity. In recent years, the potential use of Circulating Tumor Cells or multianalytes such as a circulating microRNA and NETest have been widely discussed. They offer superior diagnostic parameters in comparison to traditional biomarkers and depict disease status in a more comprehensive way. Despite a lot of promise, no international standards have yet been developed regarding their routine use and clinical application. In this literature review, we describe the analytes used over the years and cover novel biomarkers that could find a use in the future. We discuss their pros and cons while showcasing recent advances in the field of neuroendocrine tumor biomarkers.

Predicting Overall Survival in Patients with Nonmetastatic Gastric Signet Ring Cell Carcinoma: A Machine Learning Approach

Background and Aims

Accurate prediction is essential for the survival of patients with nonmetastatic gastric signet ring cell carcinoma (GSRC) and medical decision-making. Current models rely on prespecified variables, limiting their performance and not being suitable for individual patients. Our study is aimed at developing a more precise model for predicting 1-, 3-, and 5-year overall survival (OS) in patients with nonmetastatic GSRC based on a machine learning approach.

Methods

We selected 2127 GSRC patients diagnosed from 2004 to 2014 from the Surveillance, Epidemiology, and End Results (SEER) database and then randomly partitioned them into a training and validation cohort. We compared the performance of several machine learning-based models and finally chose the eXtreme gradient boosting (XGBoost) model as the optimal method to predict the OS in patients with nonmetastatic GSRC. The model was assessed using the receiver operating characteristic curve (ROC).

Results

In the training cohort, for predicting OS rates at 1-, 3-, and 5-year, the AUCs of the XGBoost model were 0.842, 0.831, and 0.838, respectively, while in the testing cohort, the AUCs of 1-, 3-, and 5-year OS rates were 0.749, 0.823, and 0.829, respectively. Besides, the XGBoost model also performed better when compared with the American Joint Committee on Cancer (AJCC) stage. The performance for this model was stably maintained when stratified by age and ethnicity.

Conclusion

The XGBoost-based model accurately predicts the 1-, 3-, and 5-year OS in patients with nonmetastatic GSRC. Machine learning is a promising way to predict the survival outcomes of tumor patients.