How to treat gastrinomas in patients with multiple endocrine neoplasia type1: surgery or long-term proton pump inhibitors?

In patients with multiple endocrine neoplasia type 1 syndrome (MEN 1) and Zollinger-Ellison syndrome (ZES), gastrinomas arise from the duodenum, about 60% are multiple, and about 15% of patients have coexisting pancreatic gastrinomas, which can be localized by the selective arterial secretagogue injection test (SASI test). The guidelines (GLs) by the Japanese Neuroendocrine Tumor Society (JNETS) recommend surgical resection for functioning duodenopancreatic neuroendocrine tumors (NETs), including gastrinomas, in patients with MEN1 (Grade A, 100% agreement among members). Conversely, the GLs of the National Comprehensive Cancer Network (NCCN) in the USA recommend observation and treatment with proton pump inhibitors (PPIs) or exploratory surgery for occult gastrinomas. An international Consensus Statement (ICS) from the European Union (EU) also does not recommend resection of gastrinomas in patients with MEN1, despite some surgeons having reported surgery being curative for gastrinomas in MEN1 patients. In this review, we discuss the serious side effects and tumorigenic effects of the prolonged use of PPIs and the safety and curability of surgery, supported by our results of curative surgery for gastrinomas in 20 patients with MEN1 over 30 years. We conclude that surgery should be the first-line treatment for gastrinomas in MEN1 patients.

Diagnosis of Developmental Dysplasia of the Hip by Ultrasound Imaging Using Deep Learning.

BACKGROUND: A timely diagnosis of developmental dysplasia of the hip (DDH) is important for satisfactory clinical outcomes. Ultrasonography is a useful tool for DDH screening; however, it is technically demanding. We hypothesized that deep learning could assist in the diagnosis of DDH. In this study, several deep-learning models were assessed to diagnose DDH on ultrasonograms. This study aimed to evaluate the accuracy of diagnoses made by artificial intelligence (AI) using deep learning on ultrasound images of DDH. METHODS: Infants who were up to 6 months old with suspected DDH were included. DDH diagnosis using ultrasonography was performed according to the Graf classification. Data on 60 infants (64 hips) with DDH and 131 healthy infants (262 hips) obtained from 2016 to 2021 were retrospectively reviewed. For deep learning, a MATLAB deep learning toolbox (MathWorks, Natick, MA, US) was used, and 80% of the images were used as training data, with the rest as validation data. Training images were augmented to increase data variation. In addition, 214 ultrasound images were used as test data to evaluate the AI's accuracy. Pre-trained models (SqueezeNet, MobileNet_v2, and EfficientNet) were used for transfer learning. Model accuracy was evaluated using a confusion matrix. The region of interest of each model was visualized using gradient-weighted class activation mapping (Grad-CAM), occlusion sensitivity, and image LIME. RESULTS: The best scores for accuracy, precision, recall, and F-measure were all 1.0 in each model. In DDH hips, the region of interest for deep learning models was the area lateral to the femoral head, including the labrum and joint capsule. However, for normal hips, the models highlighted the medial and proximal areas where the lower margin of the os ilium and the normal femoral head exist. CONCLUSIONS: Ultrasound imaging with deep learning can assess DDH with high accuracy. This system could be refined for a convenient and accurate diagnosis of DDH. LEVEL OF EVIDENCE: Level-Ⅳ.

Phase I/II study of streptozocin monotherapy in Japanese patients with unresectable or metastatic gastroenteropancreatic neuroendocrine tumors.

BACKGROUND: This phase I/II study was conducted to evaluate the efficacy, safety and pharmacokinetics of streptozocin (STZ) in Japanese patients with unresectable or metastatic gastroenteropancreatic neuroendocrine tumors. METHODS: Twenty-two patients received up to 4 cycles of intravenous STZ at either 500 mg/m2 once daily for 5 consecutive days every 6 weeks (daily regimen) or at 1000-1500 mg/m2 once weekly for 6 weeks (weekly regimen). Tumor response was evaluated using the modified RECIST criteria ver. 1.1, and adverse events were assessed by grade according to the National Cancer Institute CTCAE (ver. 4.0). RESULTS: Fourteen (63.6%) patients completed the study protocol. No patients had complete response; partial response in 2 (9.1%), stable disease in 17 (77.3%), non-complete response/non-progressive disease in 2 (9.1%) and only 1 (4.5%) had non-evaluable disease. Excluding the latter, the response rate in the daily and weekly regimens was 6.7% (1/15) and 16.7% (1/6), respectively, with an overall response rate of 9.5% (2/21). However, the best overall response in each patient showed that the disease control rate was 100%.Adverse events occurred in all 22 patients, including 17 grade 3 adverse events in 11 patients; however, no grade 4 or 5 adverse events were reported. Prophylactic hydration and antiemetic treatment reduced the severity and incidence of nephrotoxicity, nausea and vomiting. Plasma STZ concentrations decreased rapidly after termination of infusion, with a half-life of 32-40 min. Neither repeated administration nor dose increases affected pharmacokinetic parameters. CONCLUSIONS: STZ may be a useful option for Japanese patients with unresectable or metastatic gastroenteropancreatic neuroendocrine tumors.

Nationwide registry for patients with neuroendocrine neoplasm of pancreas, gastrointestinal tract, lungs, bronchi, or thymus in Japan.

BACKGROUND: Neuroendocrine neoplasm (NEN) is a comparatively rare tumor that has been considered indolent. Due to these characteristics, detailed epidemiological data have not been analyzed in Japan. To elucidate the present status of NEN diagnosis and treatment in Japan, we started a registry cohort study in January 2015. METHODS: Patients pathologically diagnosed with NENs of the pancreas, gastrointestinal tract, lungs, bronchi, or thymus after January 2012 were enrolled in this registry after the date of ethics review committee approval in each hospital or institute. Follow-up was continued for enrolled patients. RESULTS: During 5 years of enrollment between January 2015 and December 2019, a total of 1526 participants from 63 departments were enrolled in this registry (mean, 305.2 participants/year), covering approximately 5.8% of the annual incidence of NENs in Japan. For pancreatic NEN, 41.9% of patients had metastasis and the dominant metastatic site was the liver, at twice the rate of lymph node metastasis in the current registry. In contrast, the frequency of lymph node metastasis from gastrointestinal (GI)-NEN was similar to that of the liver. The distribution of WHO 2019-based grades varied according to the primary site. Low-to-intermediate grade (G1-G2) was dominant for duodenal, jejunal/ileal, rectal, and pancreatic NENs, whereas high grade (G3 or NEC) was dominant for esophageal, stomach, and colon NENs. For PanNENs, G3 and NEC accounted only for 1.6% and 2.9%, respectively. CONCLUSIONS: These cohort data provide crucial information for clinical research to clarify the characteristics of NENs in Japan.

Recent epidemiology of patients with gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NEN) in Japan: a population-based study.

BACKGROUND: The worldwide prevalence and incidence of neuroendocrine neoplasms (NEN) have been increasing recently, although few studies have analyzed data on the current situation of NENs in Japan. Here, the Japan Neuroendocrine Tumor Society (JNETS) planned to investigate the recent incidence and distribution of these tumors using data from the national cancer registry started in 2016. This study examined the incidence and distribution of primary sites as well as rate of advanced disease from this population-based registry. METHODS: A retrospective, population-based study using data from the national cancer registry in Japan (NCR) was conducted to evaluate patients with gastro-entero-pancreatic NEN (GEP-NEN) in 2016. Associated population data were used to determine annual age-adjusted incidences. RESULTS: A total of 6735 individuals were diagnosed with GEP-NEN in Japan in 2016. Annual onset incidence was 0.70/100,000 for pancreatic NEN and 2.84/100,000 for gastrointestinal NEN. NEN in the ileum accounted for only 1% of total GEP-NENs in Japan. Most NENs in the esophagus or lungs were neuroendocrine carcinomas (NECs), while the majority of those in the duodenum, ileum, appendix and rectum were grade 1 neuroendocrine tumors (NETs). Median age at initial diagnosis was in between 60 to 65. Tumors in the duodenum, appendix and rectum were mostly limited to local, while those in the esophagus, stomach and colon tended to show distant metastasis. In Japan, initial treatment for GEP-NENs was resection even if the tumor was NEC. CONCLUSIONS: This is the first report of a national registry-based incidence and distribution of GEP-NEN in Japan. These data will serve as an important first step to determining the exact etiology and trends for this pathology in Japan.

Optimal strategy of systemic treatment for unresectable pancreatic neuroendocrine tumors based upon opinion of Japanese experts.

BACKGROUND/OBJECTIVES: A number of therapeutic agents have been reported to be clinically useful for the management of the patients with unresectable pancreatic neuroendocrine tumors (PanNETs) including somatostatin analogues, molecular-targeted agents and cytotoxic agents. However, the optimal strategy for selection among those treatment modalities above in these patients has remained unexplored. METHODS: Japanese experts for PanNET discussed and determined the optimal treatment strategies according to the results of previously reported studies. RESULTS: The tumor volume of liver metastases and the Ki-67 labeling index were unanimously accepted as indicators of the tumor burden and tumor aggressiveness, respectively, which are two most clinically pivotal factors for determining the strategy of systemic treatment for unresectable PanNETs. In addition, for those with a relatively small tumor burden and slow disease progression, somatostatin analogues were selected as the first-line treatment agents. For those with a relatively large tumor burden and rapid tumor progression, cytotoxic agents were selected, possibly aiming at tumor shrinkage. For those of intermediate tumor volume and/or growth rate, molecular-targeted agents were selected as the first choice. Based on this strategy discussed among the experts, we tentatively prepared a MAP for proposing optimal treatment strategy and examined its validity in some patients with unresectable PanNETs. Results validated the usefulness of this MAP proposed for patients harbouring unresectable PanNETs. CONCLUSION: We herein propose a tentative MAP for optimal treatment selection for the patients harbouring unresectable PanNETs. Further large scale studies are, however, warranted to validate the usefulness of this MAP proposed in this study.

Pancreatic neuroendocrine carcinoma G3 may be heterogeneous and could be classified into two distinct groups.

BACKGROUND/OBJECTIVES: Pancreatic neuroendocrine carcinoma (PanNEC)-G3 often presents along with genetic abnormalities such as KRAS, RB1, and TP53 mutations. However, the association between these genetic findings and response to chemotherapy and prognosis has not been clarified. This study aimed to clarify the clinicopathological features of PanNEC-G3. METHODS: We performed a subgroup analysis of the Japanese PanNEN-G3 study (multicenter, retrospective study), which revealed that Rb loss and KRAS mutation were predictors of the response to platinum-based regimen in PanNEN-G3. We re-classified WHO grades of PanNENs using the 2017 WHO classification and then analyzed the clinicopathological features and prognostic factors in 49 patients with PanNEC-G3. RESULTS: The rates of Rb loss and KRAS mutation in PanNEC-G3 were 54.5% and 48.7%, respectively. Patients with Rb loss and/or KRAS mutation showed a higher response rate to first-line platinum-based regimen than those without Rb loss or KRAS mutation (object response rate 70.0% vs 33.3%, odds ratio 9.22; 95% CI 1.26-67.3, P = 0.029), but tended to have shorter overall survival rates than those without Rb loss or KRAS mutation (median 239 vs 473 days, hazard ratio 2.11; 95% CI 0.92-4.86, P = 0.077). CONCLUSIONS: Patients with PanNEC-G3 have varied clinical outcomes for platinum-based regimen. When grouped based on Rb loss and KRAS mutation, there seemed to be two groups with distinct prognoses and responses to the platinum-based regimen. PanNEC-G3 could, therefore, be classified into two distinct groups based on immunohistochemical and genetic findings.

[A Case of Thymic Carcinoma of Postoperative Liver and Mediastinal Lymph Node Metastases Where Long-Term Survival Was Achieved through Multidisciplinary Treatment].

The patient was a 67-year-old man. At the age of 60, he underwent resection of thymic carcinoma with partial resection of the right upper lobe of the lung because of invasive thymic carcinoma. The pathological diagnosis was Masaoka stage Ⅲ squamous cell carcinoma. Follow-up examination 2 years after surgery showed metastases to the mediastinall ymph node and liver. After undergoing radiotherapy of 50 Gy to the mediastinal lymph node metastasis, partial hepatectomy was performed for metastatic liver cancer. Post-operation, he received 4 courses of combination therapy of carboplatin and paclitaxel. Five years post-hepatectomy, the patient developed liver metastasis again and underwent hepatectomy for local control. Postoperative recurrent cases of thymic carcinoma generally have poor prognosis. We describe a patient with thymic carcinoma of postoperative liver and mediastinal lymph node metastases who achieved long-term survival through multidisciplinary treatment.

[A Case Report of a Difficult to Diagnose, Extremely Well-Differentiated Stomach Adenocarcinoma Diagnosed by Biopsy].

A Japanese man in his 60s presented with complaints of epigastric pain and weight loss. A gastrointestinal endoscopy revealed multiple gastric ulcers and an irregular mound located on the wall of the lower gastric body along the greater curvature, which was suspected to be cancerous. A biopsy revealed that it was a Group 2 tumor even though the biopsy was repeated 4 times. He was referred to our hospital and 3 biopsies were performed. The final result classified the tumor as Group 4. The patient underwent surgery and the pathological examination revealed an extremely well-differentiated adenocarcinoma( EWDA). An EWDA is characterized by a well-formed mucinous gland with little or no nuclear atypia, which makes preoperative biopsy diagnosis difficult.

Surgery for Pancreatic Neuroendocrine Tumor G3 and Carcinoma G3 Should be Considered Separately.

BACKGROUND: The role of surgery in pancreatic neuroendocrine neoplasm grade 3 (pNEN-G3) treatment remains unclear. We aimed to clarify the role of surgery for pNEN-G3, which has recently been reclassified as pancreatic neuroendocrine tumor-G3 (pNET-G3) and pancreatic neuroendocrine carcinoma-G3 (pNEC-G3), with and without metastases, respectively. METHODS: We analyzed a subgroup of patients from the Japanese pancreatic NEC study, a Japanese multicenter case-series study of pNEN-G3. Pathologists subclassified 67 patients as having pNET-G3 or pNEC-G3 based on morphological features. We compared the overall survival (OS) rates among patients who were grouped according to whether they had undergone tumor-targeted surgery for tumors without (SwoM) or with (SwM) metastases, or non-surgical procedures (NS). RESULTS: Data from 21 patients with pNET-G3 (SwoM, n = 6; SwM, n = 5; NS, n = 10) and 46 patients with pNEC-G3 (SwoM, n = 8; SwM, n = 5; NS, n = 33) were analyzed. OS of patients with pNET-G3 was significantly longer after SwoM and SwM than with NS (p = 0.018 and p = 0.022). In contrast, OS did not significantly differ between either SwoM or SwM and NS (p = 0.093 and p = 0.489) among patients with pNEC-G3. CONCLUSION: The role of surgery should be considered separately for pNET-G3 and pNEC-G3. Although SwoM and SwM can be considered for pNET-G3, caution is advised before considering SwM and SwoM for pNEC-G3.

[A Case of Esophageal Carcinoma with Large Intramural Metastasis to the Stomach].

We report a rare case of esophageal carcinoma with gastric wall metastasis. A 73-year-old man with dysphagia underwent endoscopy and upper GI series and chest-abdominal computed tomography, revealing esophageal carcinoma and gastric cancer, which was diagnosed as squamous cell carcinoma by biopsy. The esophageal carcinoma was located in the lower thoracic esophagus(Lt). Total gastrectomy was performed. The resected specimen showed a type 3 tumor measuring 7×7 cm in the anterior wall of the stomach. Pathologically, the depth of invasion of the stomach was SE. He died 3 months after the operation. Esophageal carcinoma with gastric intramural metastasis is very rare and has a dismal prognosis. We report a rare case of esophageal carcinoma with large intramural metastasis to the stomach.

[Two-Stage Radical Resection of a Case of Colon Cancer with Abdominal Wall Invasion and Cholangiocarcinoma].

A woman in her 50s was admitted to our hospital with fever and lower abdominal swelling. Abdominal CT/MRI examinations revealed irregular thickening of the transverse colon wall, which was attached to a subcutaneous abscess. An abdominal wall mass, a patent urachus, and a tumor in the 5th segment of the liver were also noted. Colonoscopy revealed type 2 advanced transverse colon cancer. The solitary, sessile tumor was observed at the apex of the bladder under cystoscopy, suggesting the formation of the urachal carcinoma. Transcutaneous liver biopsy obtained from the liver tumor indicated adenocarcinoma, which was morphologically different from the existing transverse colon cancer. Right hemicolectomy with resection of the umbilicus, abdominal wall, urachus, and part of the bladder wall was performed. Diagnosis of the transverse colon cancer invading the abdominal wall and bladder was confirmed by histopathological examination. Hepatectomy was performed in the next surgery, and the tumor was histopathologically diagnosed as an intrahepatic cholangiocarcinoma. Both the transverse colon cancer and the intrahepatic cholangiocarcinoma were radically resected. Radical surgical diagnostic resection may be valuable in cases of multicentric cancers of unknown primary origin, if radical resection of each individual tumor is required.

Phase II study of lanreotide autogel in Japanese patients with unresectable or metastatic well-differentiated neuroendocrine tumors.

Background Lanreotide is a long-acting somatostatin analog with demonstrated efficacy against enteropancreatic neuroendocrine tumor (NET) in the phase III (CLARINET) study. Materials and Methods In this single-arm study, Japanese patients with grade (G) 1/G2 NET received lanreotide (120 mg/4 weeks) for 48 weeks. Those who completed the study were enrolled in a long-term extension study. The primary endpoint was the clinical benefit rate (CBR) defined as a complete response, partial response (PR), or stable disease (SD) over 24-weeks. Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), safety, and pharmacokinetics. Results Thirty-two patients were recruited at 10 sites. The full analysis set (FAS) comprised 28 patients. Primary tumors were located in pancreas (12 patients), foregut (non-pancreas, lung; 1), midgut (2), hindgut (8), and unknown (5). Four patients had gastrinoma of the functional NET, and 3 had multiple endocrine neoplasia type 1. In the FAS, 39.3% had progressive disease at baseline. The CBR at 24 weeks was 64.3% (95% confidence interval; CI: 44.1-81.4), and median PFS was 36.3 weeks (95% CI: 24.1-53.1). PR was confirmed in 1 patient at 60 weeks during the extension study (ORR: 3.6%). Frequent adverse events related to lanreotide included injection site induration (28.1%), faeces pale (18.8%), flatulence (12.5%), and diabetes mellitus (12.5%). Conclusions The efficacy and safety of lanreotide in this study indicated its usefulness as a treatment option for Japanese NET patients. TRIAL REGISTRATION: JapicCTI-132,375, JapicCTI-142,698.

[A Case of Triple Negative Spindle Cell Carcinoma of the Breast and Improved Quality of Life Following Irinotecan Chemotherapy].

We report a case of triple negative spindle cell carcinoma of the breast, responsive to irinotecan chemotherapy. A 49-year old woman who had a tumor in the chest wall with a skin ulcer visited our hospital. After being diagnosed with triple negative spindle cell carcinoma of the breast, she underwent surgery, adjuvant chemotherapy, and radiation at the other hospital. Fourteen months after the surgery, she developed an ipsilateral breast tumor as a result of local recurrence. Since eribulin and paclitaxel plus bevacizumab chemotherapies were not effective, she was transferred to our hospital, and we administered irinotecan as third-line chemotherapy. Skin lesions and effusion were reduced and her quality of life improved for 4 months.

[A Case of Unresectable Locally Advanced Pancreatic Cancer Resulted in R0 Surgery after Chemotherapy].

A 67-year-old man visited our hospital for jaundice. Abdominal dynamic CT showed the hypovascular tumor at the head of the pancreas that surrounded superior mesenteric artery(SMA)at an angle of 220 degree. No metastasis in lymph nodes and other organs was observed. We diagnosed the tumor unresectable locally advanced(UR-LA)pancreatic cancer. Chemotherapy was administered with gemcitabine and nab-paclitaxel(GEM+nab-PTX)and achieved partial response. Regression in size and in range around SMA to an angle of 150 was observed. We assessed it possible to resect the tumor curatively, and performed subtotal stomach preserving pancreaticoduodenectomy and dissection of the plexus around the SMA, resulted in R0 surgery. Adjuvant chemotherapy was administered, and no recurrence was observed up to present, more than a year. It is suggested that GEM+nab-PTX can be effective as the primary therapy against UR-LA pancreatic cancer.

[Recurrent Gastric Carcinoma(Endocrine Cell Type)Successfully Treated with Multidisciplinary Therapy - A Case Report].

A 62-year-old woman was diagnosed with carcinoma of the stomach at another hospital. Distal gastrectomy with D2 dissection was performed and she was referred to our hospital. Histopathological and immunopathological examinations showed the tumor to be composed of adenocarcinoma and neuroendocrine carcinoma. The patient was followed until 4 months after the operation when an abdominal computed tomographic(CT)scan showed a metastatic tumor at S2 and S5/6 of the liver. No other organ metastases were found, and a hepatectomy was performed. The primary tumor of the stomach consisted of adenocarcinoma and neuroendocrine carcinoma; however, the resected metastatic liver tumor consisted of only neuroendocrine carcinoma. Liver and lung metastases appeared 2 months after the operation, and we started chemotherapy with VP-16 and cisplatin. After 8 courses of treatment, the lung metastases showed a CR, and the liver metastasis was SD. She is alive without lung metastases 9 months after the hepatectomy.

[A Case of Rectal Cancer Successfully Treated with Surgery and Stereotactic Radiotherapy for Metachronous Lung Metastases].

A 64-year-old woman underwent polypectomy for a rectal polyp(Isp). Pathological findings were invasion of the submucosa( 3,500 mm diameter), and she underwent anterior resection for rectal cancer(RS, pT1b, pN0, cM0, Stage I )without adjuvant chemotherapy. Lung masses were found in her right(8mm)and left lung(7mm). The tumors enlarged during the 4 month follow-up period. We decided to perform left partial pneumonectomy. The tumor was diagnosed as a lung metastasis from colon cancer by pathology. Because the right tumor was located towards the center, performing right pneumonectomy would have been quite invasive and we feared occult metastases. We decided to apply SRT(50 Gy)to the right tumor. The tumor shrunk and became a scar after treatment. There were no complications such as radiation pneumonitis. The patient was in good health without any recurrence for 12 months after SRT. Surgical resection is an optimal method to control lung metastasis from colon cancer if the lesion is operable. However, in the case of a tumor centrally located, surgical resection may cause deterioration of lung function. There are also cases with contraindications for surgery due to co-morbidities. In addition, there is no consensus on observation periods to exclude occult metastases. SRT can be an effective treatment for lung metastases from colon cancer when there are bilateral lung metastases and no metastases outside the lungs.

A case of insulinoma with non-alcoholic fatty liver disease: Roles of hyperphagia and hyperinsulinemia in pathogenesis of the disease.

Nonalcoholic fatty liver disease (NAFLD) is a serious health-related condition all over the world; the number of patients is increasing in Asian countries including Japan. Better understanding of its pathophysiology is required to develop effective therapeutics, as patients may go on to develop non-alcoholic steatohepatitis and hepatocellular carcinomas. While NAFLD is believed to be associated with metabolic risk factors such as obesity, diabetes, and dyslipidemia, its etiology remains largely unknown and the development or co-existence of NAFLD in patients with insulinoma has not been investigated. A 33-year-old male with an insulinoma, who had been hypoglycemic during the previous four years, developed abnormally elevated levels of liver enzymes and histological fatty liver characteristic of NAFLD by the time of admission to our hospital for resection of an insulinoma. His medical records for the previous eight years revealed that his bodyweight had increased gradually from 60 kg to 71 kg for seven years and then acutely increased to 79 kg in the latest one-year period. This sudden increase was thought to be due to the patient's self-described overeating of fruits to forestall hypoglycemia. Fresh fruits are rich in fructose, and the patient's triglycerides, alanine and aspartate transaminases showed an acute increase in the previous one-year period. After resection of the insulinoma, the levels of these parameters all were mostly restored, which suggests that hyperinsulinemia and subsequent hyperphagia played a role in the development of NAFLD in this case. This is the first report of patient with NAFLD and an insulinoma.

Multiple endocrine neoplasia type 1 in Japan: establishment and analysis of a multicentre database.

OBJECTIVE: Multiple endocrine neoplasia type 1 (MEN1) is less well recognized in Asian countries, including Japan, than in the West. The clinical features and optimal management of MEN1 have yet to be clarified in Japan. The aim of this study was to clarify the clinical features of Japanese patients with MEN1. DESIGN/PATIENTS: We established a MEN study group designated the 'MEN Consortium of Japan' in 2008, and asked physicians and surgeons to provide clinical and genetic information on patients they had treated. Of 680 registered patients, 560 were analysed. MEASUREMENTS: Clinical and genetic features of Japanese patients with MEN1 were examined. RESULTS: Primary hyperparathyroidism, gastroenteropancreatic neuroendocrine tumours (GEPNET), and pituitary tumours were seen in 94·4%, 58·6% and 49·6% of patients, respectively. The prevalence of insulinoma was higher in the Japanese than in the West (22%vs 10%). In addition, 37% of patients with thymic carcinoids were women, while most were men in western countries. The MEN1 mutation positive rate was 91·7% in familial cases and only 49·3% in sporadic cases. Eight novel mutations were identified. Despite the availability of genetic testing for MEN1, the application of genetic testing, especially presymptomatic diagnosis for at-risk family members appeared to be insufficient. CONCLUSIONS: We established the first extensive database for Asian patients with MEN1. Although the clinical features of Japanese patients were similar to those in western countries, there were several characteristic differences between them.

Delay in the diagnosis of multiple endocrine neoplasia type 1: typical symptoms are frequently overlooked.

The morbidity and mortality of individuals with multiple endocrine neoplasia type 1 (MEN1) can be reduced by early diagnosis of MEN1 and related endocrine tumors. To find factors contributing to early diagnosis, we collected clinical information on MEN1 patients through a MEN study group, "MEN Consortium of Japan" and analyzed the time of initial symptom-dependent detection of parathyroid tumors, gastro-entero-pancreatic neuroendocrine tumors (GEPNETs) and pituitary tumors, and that of tumor detection-dependent MEN1 diagnosis in 560 patients. Main tumors were identified up to 7.0 years after symptoms appeared and there was no difference in age at the diagnosis of GEPNETs alone between probands and family members. In patients with typical symptoms (peptic ulcers, urolithiasis, fasting hypoglycemia, bone fracture/loss and amenorrhea), the mean interval between symptom manifestation and tumor detection was extended up to 9.6 years. In particular, 21.7% (5/23) of patients with amenorrhea were diagnosed with pituitary tumors in under one year. In patients with peptic ulcers (from parathyroid tumors or GEPNETs) and urolithiasis (from parathyroid tumors), the interval was positively correlated with age at tumor detection. The interval between tumor detection and MEN1 diagnosis was also prolonged to approximately four years in patients with fasting hypoglycemia (from GEPNETs) and amenorrhea. A substantial delay in the diagnosis of symptom-related tumors and subsequent MEN1 and inadequate screening of GEPNETs in family members were indicated. A greater understanding of MEN1 may assist medical practitioners to make earlier diagnoses, to share patients' medical information and to give family members sufficient disease information.