Primary Neuroendocrine Tumors Research Articles

Primary Neuroendocrine Tumor of the Breast: A Case Report and Review of Current Guidelines

Primary Neuroendocrine Tumor of the Breast: A Case Report and Review of Current Guidelines

Clinicopathological and epigenetic differences between primary neuroendocrine tumors and neuroendocrine metastases in the ovary

AbstractCurrently, the available literature provides insufficient support to differentiate between primary ovarian neuroendocrine tumors (PON) and neuroendocrine ovarian metastases (NOM) in patients. For this reason, patients with a well‐differentiated ovarian neuroendocrine tumor (NET) were identified through electronic patient records and a nationwide search between 1991 and 2023. Clinical characteristics were collected from electronic patient files. This resulted in the inclusion of 71 patients with NOM and 17 patients with PON. Histologic material was stained for Ki67, SSTR2a, CDX2, PAX8, TTF1, SATB2, ISLET1, OTP, PDX1, and ARX. DNA methylation analysis was performed on a subset of cases. All PON were unilateral and nine were found within a teratoma (PON‐T+). A total of 78% of NOM were bilateral, and none were associated with a teratoma. PON without teratomous components (PON‐T−) displayed a similar insular growth pattern and immunohistochemistry as NOM (p > 0.05). When compared with PON‐T+, PON‐T− more frequently displayed ISLET1 positivity and were larger, and patients were older at diagnosis (p < 0.05). Unsupervised analysis of DNA methylation profiles from tumors of ovarian (n = 16), pancreatic (n = 22), ileal (n = 10), and rectal (n = 7) origin revealed that four of five PON‐T− clustered together with NOM and ileal NET, whereas four of five PON‐T+ grouped with rectum NET. In conclusion, unilateral ovarian NET within a teratoma should be treated as a PON. Ovarian NET localizations without teratomous components have a molecular profile analogous to midgut NET metastases. For these patients, a thorough review of imaging should be performed to identify a possible undetected midgut NET and a corresponding follow‐up strategy may be recommended.

7940 Insulinoma as a Rare Manifestation of MEN4

Abstract Disclosure: H. Han: None. J. Moalem: None. A.R. Shih: None. B.J. Gigliotti: None. Background/Objective: Multiple endocrine neoplasia 4 (MEN4) is a rare syndrome that is caused by germline mutations in CKDN1B. Its phenotypic expression is similar to multiple endocrine neoplasia 1 (MEN1). Manifestations include primary hyperparathyroidism (PHPT), pituitary adenomas, and pancreatic neuroendocrine tumors (NET). Prevalence of MEN4 is less than one per million. Case Report: A 55-year-old female with history of hypercalcemia presented with symptomatic hypoglycemia. She had a fasting plasma glucose of 41mg/dL, proinsulin of 84.3 pmol/L, insulin level of 24 uIU/mL, c-peptide of 5.2 ng/mL, and beta hydroxybutyrate level of 0.34 mmol/L, consistent with endogenous hyperinsulinism. She was incidentally noted to have PHPT. CT abdomen showed a 1.5 x 1.1 x 1.0 cm pancreatic lesion consistent with an insulinoma. Pathology from subsequent Whipple surgery showed that it was a well-differentiated neuroendocrine tumor with no metastasis. She became normoglycemic after surgery. Germline testing revealed a variant of unknown significance in CDKN1B (p.R93W). Discussion: Increasing evidence suggests that MEN4 exhibits subtle differences in penetrance and natural history compared to MEN1. A recent systemic review of MEN4 cases showed that most gastrointestinal NETs in MEN4 are non-functional NETs and gastrinomas; to date, no insulinomas have been reported. PHPT in MEN4 may exhibit a lower risk of recurrence after parathyroidectomy. This case highlights the importance of germline genetic testing when a patient presents with clinical manifestations of MEN1. Conclusion: This is the first reported case of insulinoma in MEN4. Presentation: 6/3/2024

Insulinoma-associated protein-1 (INSM-1) is a useful diagnostic marker for the evaluation of primary thymic neuroendocrine neoplasms: an immunohistochemical study of 27 cases.

Insulinoma-associated protein 1 (INSM1) immunohistochemistry has been established as a sensitive and reliable immunohistochemical marker for detecting neuroendocrine differentiation in tumors across various organ systems. However, this marker has not been adequately investigated in primary thymic neuroendocrine tumors. We have studied a series of 27 cases of primary neuroendocrine carcinomas of the thymus, including 3 typical carcinoids, 18 atypical carcinoids, 4 large cell neuroendocrine carcinomas, and 2 small cell carcinomas. Immunostaining on whole tissue sections for INSM-1 was evaluated. Results of immunostaining for chromogranin and synaptophysin were also evaluated. 26/27 tumors (96%) demonstrated nuclear positivity for INSM1. 18 tumors (67%) showed strong and diffuse nuclear staining (3 +), 3 tumors (11%) moderate (2 +) nuclear staining, and 5 tumors (19%) showed weak (1 +) nuclear staining. The average percentage of tumor cells positive for INSM1 was 76%. Only one tumor, a small cell carcinoma, was negative. All tumors were positive for synaptophysin, and 26/27 (96%) were positive for chromogranin A. This study confirms that INSM1 immunohistochemistry is a sensitive marker of neuroendocrine differentiation in primary thymic neuroendocrine neoplasms and demonstrates similar performance characteristics compared to other organ systems. The nuclear staining with this marker offers the advantage of eliminating some of the ambiguity in the interpretation sometimes encountered with other markers. An added advantage is the consistent staining across the entire spectrum of neuroendocrine tumors of this organ.

1167P Outcomes of local and systemic treatment in primary hepatic neuroendocrine neoplasms (PHNEN)

1167P Outcomes of local and systemic treatment in primary hepatic neuroendocrine neoplasms (PHNEN)

Primary neuroendocrine tumor of the perihilar bile duct: A case report

Neuroendocrine tumors (NETs) arising from extrahepatic bile ducts are very rare. We present a patient with perihilar NET who was operated on with a preoperative diagnosis of Klatskin tumor. A 58-year-old female patient was admitted with abdominal pain and jaundice. Laboratory data showed elevated serum bilirubin levels and liver function tests. Computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) findings were consistent with perihilar bile duct tumor. The patient was operated on with a diagnosis of Klatskin tumor. She underwent right hepatectomy, resection of the extrahepatic bile duct, portal lymphadenectomy and Roux-en-Y hepaticojejunostomy. The final pathologic examination of the resected specimen demonstrated a well differentiated neuroendocrine tumor (Grade 1). NETs originating from perihilar bile ducts are extremely rare, and preoperative definite diagnosis is very difficult. It should be kept in mind that NET may be one of the rare causes of perihilar bile duct obstruction.

Development of an artificial intelligence–based model to predict early recurrence of neuroendocrine liver metastasis after resection

PurposeWe sought to develop an artificial intelligence (AI)–based model to predict early recurrence (ER) after curative-intent resection of neuroendocrine liver metastases (NELMs). MethodsPatients with NELM who underwent resection were identified from a multi-institutional database. ER was defined as recurrence within 12 months of surgery. Different AI-based models were developed to predict ER using 10 clinicopathologic factors. ResultsOverall, 473 patients with NELM were included. Among 284 patients with recurrence (60.0%), 118 patients (41.5%) developed an ER. An ensemble AI model demonstrated the highest area under receiver operating characteristic curves of 0.763 and 0.716 in the training and testing cohorts, respectively. Maximum diameter of the primary neuroendocrine tumor, NELM radiologic tumor burden score, and bilateral liver involvement were the factors most strongly associated with risk of NELM ER. Patients predicted to develop ER had worse 5-year recurrence-free survival and overall survival (21.4% vs 37.1% [P = .002] and 61.6% vs 90.3% [P = .03], respectively) than patients not predicted to recur. An easy-to-use tool was made available online: (https://altaf-pawlik-nelm-earlyrecurrence-calculator.streamlit.app/). ConclusionAn AI-based model demonstrated excellent discrimination to predict ER of NELM after resection. The model may help identify patients who can benefit the most from curative-intent resection, risk stratify patients according to prognosis, as well as guide tailored surveillance and treatment decisions including consideration of nonsurgical treatment options.

Metabolic Tumor Volume on 18-Fluorodeoxyglucose Positron Emission Tomography as a Prognostic Marker of Survival in Patients With Locally Advanced or Metastatic Neuroendocrine Neoplasms Treated With 177Lutetium-DOTA-Octreotate Peptide Receptor Radionuclide Therapy.

We investigated metabolic tumor volume (MTV) and total lesion glycolysis (TLG) on pre-treatment FDG-PET as prognostic markers for survival in patients with metastatic neuroendocrine neoplasms (NENs) receiving peptide receptor radionuclide therapy (PRRT). A retrospective review of patients with metastatic NENs receiving PRRT was undertaken. Pre-treatment FDG-PET images were analyzed and variables collected included MTV and TLG (dichotomized by median into high vs low). Main Outcomes were overall survival (OS) and progression-free survival (PFS) by MTV and TLG (high vs low). One hundred five patients were included. Median age was 64 years (50% male). Main primary NEN sites were small bowel (43.8%) and pancreas (40.0%). Median MTV was 3.8 mL and median TLG was 19.9. Dichotomization formed identical cohorts regardless of whether MTV or TLG were used. Median OS was 72 months; OS did not differ based on MTV/TLG high versus low (47.4 months vs not reached; hazard ratio, 0.43; 95% confidence interval [CI], 0.18-1.04; P = 0.0594). Median PFS was 30.4 months; PFS differed based on MTV/TLG high versus low (21.6 months vs 45.7 months; hazard ratio, 0.35; 95% CI, 0.19-0.64; P = 0.007). Low MTV/TLG on pre-treatment FDG-PET was associated with longer PFS in metastatic NEN patients receiving PRRT.

Primary Presacral Neuroendocrine Tumors Presented by Lumbosacral Pain: a Case Report

Primary presacral neuroendocrine tumors (NETs) are exceedingly rare and often present with extensive metastases, posing significant challenges for clinical management. We report a case of a presacral neuroendocrine tumor in a 68-year-old male who presented with lumbosacral pain. Enhanced MRI revealed a soft tissue mass at the sacrococcygeal region, while whole-body enhanced 18F-PET/CT identified small intratumoral vessels and involvement of the adjacent rectal posterior wall, mesorectal fascia, presacral fascia, and sacrococcygeal bones, accompanied by multiple lymph node metastases and widespread metastases to the lungs, liver, and bones. A CT-guided biopsy confirmed the diagnosis of a grade 2 (G2) neuroendocrine tumor. Given the tumor's extensive metastasis and aggressive nature, surgical intervention was deemed unsuitable, and the patient was treated with sulfatinib. Sulfatinib shows significant potential in managing advanced neuroendocrine tumors, providing an effective therapeutic option for patients with such complex and high-risk conditions.

Merkel cell: Friend or felon

Abstract Merkel cells are perceived as tactile receptors within skin and oral mucosa containing abundant intermediate filaments but lacking characteristic condensation of tonofilaments, hence are also referred to as non-keratinocytes. Merkel cell carcinomas (MCCs) are primary aggressive neuroendocrine neoplasms occurring in elderly individuals. Toker in 1972 reported MCC of skin pointing towards sweat glands as the source of origin which was later rectified by Tang with the aid of ultrastructural studies as Merkel cells to be a lineage of such tumours. Normally, Merkel cells are abundant in the gingiva and vermillion border of the lip and thus these are the common sites for this neoplasm. Histopathologically, MCC mimics varied other carcinomas, hence requiring a thorough diagnostic protocol. We present a case of challenging histopathology which on immunohistochemical analysis with a unique cytokeratin profile and neurofilament staining pattern helped in reaching a definitive diagnosis.

Unveiling inequalities: An analysis of treatment disparities of primary gallbladder neuroendocrine tumors by race, ethnicity, and socioeconomic status from the National Cancer Database.

e16385 Background: Gallbladder neuroendocrine tumors (NETs) are exceedingly rare tumors and carry a poor prognosis. Racial/ethnic disparities and socioeconomic status have been known to influence cancer treatment and outcomes. This study explores racial/ethnic and socioeconomic disparities in treatment patterns of primary gallbladder NETs, focusing on factors affecting receipt of chemotherapy and multimodal therapy. Methods: We analyzed primary gallbladder NETs patients using the National Cancer Database (NCDB) from 2004 to 2020. Racial groups were divided into White and Black categories, and then those groups were further divided into Hispanic White, non-Hispanic White, Hispanic Black, and non-Hispanic Black categories according to ethnicity. We considered socioeconomic factors, tumor histology, and facility type. Logistic regression was used to determine the odds of receiving chemotherapy and multimodality therapy. The significance of disparities was determined using odds ratio (OR) and p-value. Results: Of 1,195 primary gallbladder NET patients, 59% (708 patients) underwent surgery. These patients had a median age of 65 years, with a female majority (64%) and predominantly White ethnicity (73.6%). Insurance coverage varied, with 48.9% having Medicare and 35.6% private insurance, while 3.9% were uninsured and 8.6% were covered by Medicaid. The study highlighted key factors affecting the receipt of surgery. Notably, racial disparities were apparent, with Black patients less likely to receive surgery compared to White patients (OR: 0.52; P < .001). Furthermore, patients with typical carcinoid tumors were markedly more likely to receive surgery than those with other histology (OR: 10.93; P < .001). The type of treatment facility was influential, with patients in Academic/Research Programs more likely to receive surgery (OR: 0.41; P < .001) than those in Community Cancer Programs. Conclusions: This study highlights racial and socioeconomic disparities in chemotherapy and multimodality therapy for gallbladder NETs, with Black, uninsured, and Medicaid-insured patients less likely to receive treatment. These findings call for targeted policy and healthcare reforms to ensure equitable access and outcomes for all patients with this condition. [Table: see text]

Quality of life (QoL) benefits following 177Lu-DOTATATE therapy in patients (pts) with 68Ga-DOTATATE PET positive primary site agnostic neuroendocrine tumors (NET).

e16291 Background: The QoL experience during the 1st year of follow up for 68Ga-DOTATATE PET positive primary site agnostic pts with progressive metastatic NET enrolled in a prospective single arm clinical trial of 177Lu-DOTATATE therapy (OZM 067) is described here. Methods: Pts with progressive NET, Ki67 Index < 30%, adequate organ function & ECOG £2 were eligible. Only pts demonstrating positive disease (Krenning score 3-4) on 68Ga-DOTATATE PET were eligible to proceed to 177Lu-DOTATATE therapy (4 cycles at 8- to 12- week intervals. Primary outcome was progression free survival (PFS) at 12 mths. QoL (EORTC QLQ 30 and GINET21) at baseline, 6, 12, 18, 24, 30 months were recorded. Summary scores at time point of interest, and their change from baseline were estimated using a mixed model repeated measure, with baseline assessment included in the model as covariate. Data were normalized with a range of 0-100. A positive change score for Global Summary Status, Functioning Domains, and a negative change score for Symptom Scales and Items represent improvement. A ≥5 point change score is used as a threshold for Minimal Clinically Important Difference (MCID). Results: 195 pts were enrolled. 13 pts were 68Ga-DOTATATE PET negative while 5 pts withdrew consent. 177 pts received at least one dose of 177Lu-DOTATATE. All pts enrolled were eligible for a minimum of 12 mths follow up at time of data lock. The primary site was GEPNET in 143 (81%) and non GEPNET in 34 (19%). At 12 mths, the median follow-up was 33 (range 3-71) mths. PFS and OS were 81 (95% CI: 75-86)% and 92 (87-95)% respectively. QoL data at the following timepoints baseline, 6 & 12 (±2) mths were available in 174,128 & 111 pts respectively. The top three symptoms captured in EORTC QLQ 30 was Fatigue (32.5 SD 23.8) , Insomnia (26.7 SD 28.1) and Diarrhea (22.1 SD 29.4). At 12 mths, an improvement in mean score of ≥MCID in Global Health status (GHS) (+5.4), Role Fc Scale (+7,1), Social Fc Scale (+8.7) and multiple symptoms (Fatigue, Pain, Appetite, Constipation, Diarrhea, Financial Difficulties), Sexual fc, Social, Body image (Table 1) were captured. Conclusions: Patients with primary site agnostic 68Ga-DOTATATE PET positive NET experienced improvement in multiple quality of life domains including multiple symptoms post 177Lu-DOTATATE at 12 mths. Sexual fc and body image had the largest improvement. Clinical trial information: NCT02743741 . [Table: see text]

213P Clinical characteristics and treatment outcomes of primary hepatic neuroendocrine neoplasms (PHNEN)

213P Clinical characteristics and treatment outcomes of primary hepatic neuroendocrine neoplasms (PHNEN)

A neuropsychological profile for high-grade primary central nervous system neuroendocrine tumor (CNS NET): a single-case study.

Objective: Neuroendocrine tumors (NETs) are neoplasms that primarily occur in the lungs, appendix, small intestine, pancreas, and rectum, and typically metastasize to the liver or lymph nodes. However, in rare cases NETs can originate in the central nervous system (CNS). Understanding primary CNS NET neuropsychological manifestations aids in recommendations for neurocognitive follow-up, treatment and lifestyle planning, and future research. Method: Given the dearth of neuropsychological research for CNS NETs, we present a case seen in a 43-year-old woman. Results: Initial and 8-month follow-up neuropsychological evaluations of the patient revealed a Major Neurocognitive Disorder where the pattern of findings was consistent with tumor location and additional treatment-related factors. Reliable change indices at her re-evaluation revealed declines in verbal and visual memory, with statistical, yet not clinical, improvements in different domains. Follow-up monitoring of comprehensive care continued to occur after neuropsychological evaluations. Conclusions: This case study assists in the characterization of initial and follow-up neuropsychological presentation of a primary CNS NET, where evaluations helped inform clinical care and functional recommendations. This case demonstrates the importance for neuropsychologists to have awareness of various conditions, even rare conditions, which can inform a systematic approach to research and clinical care with neuro-oncological populations.

Appendiceal NET in an 18-year-old woman, the youngest case of MEN4 with neuroendocrine manifestation: case report and review of the current literature

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominantly inherited syndrome. It is caused by loss-of-function mutation of the MEN1 gene, and characterized by variable association of primary hyperparathyroidism, pituitary adenomas and neuroendocrine tumours (NETs). Up to 3% of MEN1-like syndromes present a loss-of-function mutation in the tumour-suppressor gene CDKN1B, and therefore constitute MEN4 syndrome. Data on MEN4 clinical behaviour, penetrance and associated manifestations are still incomplete. We report the case of a young woman diagnosed with a rare NET G1 of the appendix at the age of 18 years. Genetic analysis revealed a germline missense mutation (c.397C>A), present in heterozygosity, of codon 133 in the CDKN1B gene. To date only 26 mutations of CDKN1B have been described in association with a MEN4 phenotype. Subsequently, the patient’s sister, father and paternal uncle were found to be carriers of the same mutation but showed no clinical or biochemical signs of disease. This is currently the youngest case of MEN4 with a gastrointestinal tract NET reported in the literature, and the first with appendiceal involvement. Despite the absence of disease within the proband’s family, ongoing screening would seem to be warranted, along the lines of that described by other authors for MEN1 patients. KEY WORDS: MEN4, CDKN1B mutations, youngest case of NET in MEN4, appendiceal NET, MEN4 review.

Non-metastatic primary neuroendocrine neoplasms of the breast: a reference cancer center's experience of a heterogenous entity.

Primary neuroendocrine neoplasms of the breast (Br-NENs) are rare. The classification has been updated in recent years making interpretation of the data published challenging. It is unclear whether neuroendocrine differentiation is associated with poorer prognosis and what treatment approaches should be applied. The database for breast cancer patients treated between 2009 and 2022 at the Maria Sklodowska-Curie National Research Institute of Oncology Branch Krakow was explored to search for Br-NENs. Patients' medical and pathological data were collected and analyzed. We included 22 females with Br-NEN without metastases at the time of diagnosis. The median age was 64 years (range: 28-88), Of the cases, 18 were hormone receptor positive, all were HER-2 negative, the median Ki67 was 27% (10-100%). The median tumor size at the time of diagnosis was 29.5mm (7-75mm), 9 patients were N-positive. DCIS was present in 5 cases. Only one case was negative for chromogranin and synaptophysin staining, but data were missing for 4 cases. Nine patients received adjuvant chemotherapy, mainly based on anthracyclines and taxanes, while 16 received adjuvant hormonal therapy and 15 received postoperative radiotherapy. Radical surgery was performed in all patients, but two underwent suboptimal tumorectomy. One patient had local recurrence, three experienced metastatic disease, all involving the lungs, but these patients are still alive. The median follow-up was 96 months (8-153). Two patients died, with a follow up time of no recurrence >4 years. Our results were compared to twelve case series collecting clinical data on Br-NENs, with median patient number of 10.5 (range: 3-142). Br-NENs represent a heterogenous group of diseases, lacking data from prospective studies or clinical trials. There are no established treatment standards tailored for Br-NENs. Our patients' cohort exhibited a favorable prognosis, potentially attributed to lower tumor stage and Ki67 index compared to other reported case series. We suggest that radical surgery and postoperative radiotherapy be administered akin to standard treatment for breast cancer of no special type. ESMO also advocates for this approach in systemic treatment, although we recommend considering platinum-based chemotherapy for patients with poorly differentiated Br-NENs exhibiting high Ki67.

Primary Neuroendocrine Tumor of the Testis Associated With Cardiac Symptoms: A Case Report and Literature Review

Primary Neuroendocrine Tumor of the Testis Associated With Cardiac Symptoms: A Case Report and Literature Review

Abstract PO2-16-11: Real-World Data of Neuroendocrine Neoplasms of Breast

Abstract Background: Primary neuroendocrine neoplasms (NEN) of breast are rare and heterogeneous. WHO has classified NENs of non-endocrine organs into three distinct categories in 2022, however real-world data on outcomes of patients with NENs of non-endocrine organs under this new classification system are still sparse. Real world experience regarding demography, clinical presentation, treatment response, and prognosis can help identify potential areas of improvement in the management of breast NEN. Methods: Here, we present our findings from patients with NEN of breast in the Cleveland Clinic Foundation between 2000 and 2023. Pathology reports were reviewed to confirm NEN of breast origin. Neuroendocrine differentiation was determined by tumor histology and immunohistochemistry (IHC). For metastatic tumors at presentation, primary organ was determined by IHC and clinical presentation. Overall survival (OS) was from date of diagnosis of NEN. Recurrence is redemonstration of tumor following curative intent therapy, and progression is increase in tumor burden. T-test and log-rank test were used in statistical analyses. Results: Total of 97 patients were identified. Of these, 79 presented with localized disease, 18 were metastatic at presentation. 88 (91%) were invasive ductal carcinoma (IDC), and 64 (81%) were local disease at presentation and rest were metastatic. Gender spread was 92:5 (F:M). Patients with ER + disease was 84/96, PR + disease was 71, and 4/93 patients had overexpression of HER2. Median age was 70 at diagnosis. 11 patients underwent neoadjuvant chemotherapy, 15 patients underwent adjuvant chemotherapy (AC), and 58/84 patients underwent hormonal adjuvant therapy. For localized disease, median recurrence free survival (RFS) was 165 months (144-NA), and recurrence rate was 8/79 (10%). Recurrence rate for local IDC was 10% (6/64). Patients with metastatic disease at presentation had a median progression free survival (PFS) of 30 months, and progression rate was 7/18 (39%). For patients with metastatic disease, median lines of palliative therapy used was 2, with median duration of first line treatment being 3.5 months, and 10 months for second line. Most common surgical procedure was mastectomy, with 37% of patients undergoing management. Median duration from diagnostic biopsy to definitive surgery was 1 month. Median follow up was 28 months. Most common hormonal adjuvant option was anastrozole (58%), most common AC regimen was docetaxel and cyclophosphamide (39%), and most common first line palliative agent was letrozole (42%). Patients who underwent AC did not reach median OS, and patients who did not receive AC had a median OS of 148 months (p=0.8). Patients with grade 3 tumors had a median OS of 58.6 months, and grade 1 and 2 had a median OS of 148.1 months (p=0.5). Discussion: Current treatment strategies for NEN of breast mirror those of non-NEN of breast with similar histology and stage based on extrapolation of data. Recurrence rate was similar between IDC and SPC. In our cohort, survival was not significantly dependent on grade and use of AC. This might be due to the number of patients included in our study, as there was a non-significant trend towards lower OS in patients with high-grade neoplasms, and further limitations from retrospective design of study. Further research towards benefit of AC in NEN of breast and prognostic value of grading is necessary to explore management options in comparison to non-NEN of the breast. Citation Format: Serhan Unlu, Olisaemeka Ogbue, Gloria Lewis, Abdo Haddad, Hamed Daw, Baidehi Maiti. Real-World Data of Neuroendocrine Neoplasms of Breast [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-16-11.

Second Primary Neuroendocrine Tumors: A Case Series.

Second Primary Neuroendocrine Tumors: A Case Series.

Clinicopathological Findings and Treatment Outcomes of Patients with Primary Hepatobiliary Neuroendocrine Neoplasms: A Retrospective Single-institution Analysis.

Objective Primary hepatobiliary neuroendocrine neoplasms (NENs) are rare tumors exhibiting several morphological and behavioral characteristics. Considering the lack of relevant data on this topic, we evaluated the clinicopathological features and treatment outcomes of patients with primary hepatobiliary NENs. Methods/Patients We examined 43 consecutive patients treated at the National Cancer Center Hospital with pathological diagnoses of primary hepatobiliary NEN between 1980 and 2016. Results Nine patients were diagnosed with neuroendocrine tumor (NET) G1, 9 with NET G2, and 25 with neuroendocrine carcinoma (NEC) based on the World Health Organization 2019 classification. Patients with NEC had primary sites across the hepatobiliary organs, although sites in patients with NET G1 and NET G2 only included the liver and ampulla of Vater. Patients with primary extrahepatic bile duct or ampulla of Vater NENs tended to be diagnosed earlier than patients with primary gallbladder NENs. The median survival times in the NET G1, NET G2, and NEC groups were 167.9, 97.4, and 11.1 months, respectively. A good performance status, absence of distant metastases, and low tumor grade were identified as independent predictors of a favorable prognosis. Conclusion The NET-to-NEC ratio and tumor stage distribution at the diagnosis differed depending on the primary site. Patients with G1 and G2 NETs who underwent surgical resection had good prognoses, whereas those with NEC exhibited more advanced disease and poorer prognoses. The performance status, staging classification, and tumor grade are important factors to consider when devising an appropriate treatment strategy and predicting the prognoses of patients with primary hepatobiliary NEN.