Role of surgical treatments in high-grade or advanced gastroenteropancreatic neuroendocrine neoplasms

Over the last 40 years, the incidence and prevalence of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have continued to increase. Compared to other epithelial neoplasms in the same organ, GEP-NENs exhibit indolent biological behavior, resulting in more chances to undergo surgery. However, the role of surgery in high-grade or advanced GEP-NENs is still controversial. Surgery is associated with survival improvement of well-differentiated high-grade GEP-NENs, whereas poorly differentiated GEP-NENs that may benefit from resection require careful selection based on Ki67 and other tissue biomarkers. Additionally, surgery also plays an important role in locally advanced and metastatic disease. For locally advanced GEP-NENs, isolated major vascular involvement is no longer an absolute contraindication. In the setting of metastatic GEP-NENs, radical intended surgery is recommended for patients with low-grade and resectable metastases. For unresectable metastatic disease, a variety of surgical approaches, including cytoreduction of liver metastasis, liver transplantation, and surgery after neoadjuvant treatment, show survival benefits. Primary tumor resection in GEP-NENs with unresectable metastatic disease is associated with symptom control, prolonged survival, and improved sensitivity toward systemic therapies. Although there is no established neoadjuvant or adjuvant strategy, increasing attention has been given to this emerging research area. Some studies have reported that neoadjuvant therapy effectively reduces tumor burden, improves the effectiveness of subsequent surgery, and decreases surgical complications.     

中国抗癌协会神经内分泌肿瘤诊治指南（2022年版）

神经内分泌肿瘤（neuroendocrine neoplasm,NEN）是一类起源于肽能神经元和神经内分泌细胞,具有神经内分泌分化并表达神经内分泌标志物的少见肿瘤,可发生于全身各处,以肺及胃肠胰NEN（gastroenteropancreatic neuroendocrine neoplasm, GEP-NEN）最常见。国内外研究数据均提示,NEN的发病率在不断上升。美国流行病学调查结果显示,与其他类型肿瘤相比,NEN的发病率上升趋势更为显著。中国抗癌协会神经内分泌肿瘤专委会在现有循证医学证据基础上,结合已有国内外指南和共识,制订了首版中国抗癌协会神经内分泌肿瘤诊治指南,为临床工作者提供参考。     

鼻咽部神经内分泌癌的病理特征和临床分析

目的 探讨鼻咽部神经内分泌癌（neuroendocrine carcinoma，NEC）的临床病理特征、免疫组化特点、治疗方法及预后。方法 回顾性分析12例NEC患者的临床和病理资料，并复习相关文献。 结果 12例患者中，男性10例，女性2例，平均年龄49.4岁，病理类型均为小细胞型NEC。光镜下可见较小瘤细胞，呈圆形、卵圆形和梭形，核深染，胞浆少，核浆比例高，伴有较明显的病理性核分裂象，染色质细腻。免疫表型：CgA、Syn、CD56和EBERs阳性或部分阳性者分别有6例、10例、9例和3例。临床分期Ⅰ期1例，Ⅱ期1例，Ⅲ期4例，Ⅳ期5例，分期不详1例。所有患者均接受放疗和（或）化疗，至随访结束存活者9例，死亡3例。结论 鼻咽部神经内分泌癌临床上较少见，好发于中老年男性，病理类型以小细胞型为主，易出现颈部淋巴转移，就诊时大部分已处中晚期，治疗以放化疗为主。     

A case of VIPoma

This case report addresses the management of a pregnant woman in the peripartum period with a VIPoma. This rare and highly malignant neuroendocrine tumour secretes vasoactive intestinal peptide (VIP), a substance that may cause potentially life-threatening disruption to physiology.A 36-year-old woman presented for induction of labour with a three-year history of chronic diarrhoea, hypophosphataemia, palpitations and skin flushing. Raised VIP levels indicated presence of a VIPoma, however despite extensive investigation prior to pregnancy by neuroendocrine specialists, the tumour location remained unidentified.The patient delivered a healthy boy with the aid of forceps in theatre following an epidural top-up. Key features of management were a multidisciplinary approach, avoidance of triggers for VIP secretion, strict management of electrolytes and avoidance of severe changes in sympathetic tone during labour with epidural analgesia.     

Evaluation of <i>MGMT</i> Gene Methylation in Neuroendocrine Neoplasms

Unresectable neuroendocrine neoplasms (NENs) often poorly respond to standard therapeutic approaches. Alkylating agents, in particular temozolomide, commonly used to treat high-grade brain tumors including glioblastomas, have recently been tested in advanced or metastatic NENs, where they showed promising response rates. In glioblastomas, prediction of response to temozolomide is based on the assessment of the methylation status of the MGMT gene, as its product, O6 -methylguanine-DNA methyltransferase, may counteract the damaging effects of the alkylating agent. However, in NENs, such a biomarker has not been validated yet. Thus, we have investigated MGMT methylation in 42 NENs of different grades and from various sites of origin by two different approaches: in contrast to methylation-specific PCR (MSP), which is commonly used in glioblastoma management, amplicon bisulfite sequencing (ABS) is based on high-resolution, next-generation sequencing and interrogates several additional CpG sites compared to those covered by MSP. Overall, we found MGMT methylation in 74% (31/42) of the NENs investigated. A higher methylation degree was observed in welldifferentiated tumors and in tumors originating in the gastrointestinal tract. Comparing MSP and ABS results, we demonstrate that the region analyzed by the MSP test is sufficiently informative of the MGMT methylation status in NENs, suggesting that this predictive parameter could routinely be interrogated also in NENs.     

经内镜黏膜下剥离术治疗直肠神经内分泌肿瘤的疗效及安全性CSCD

目的探讨经内镜黏膜下剥离术(ESD)治疗直肠神经内分泌肿瘤(RNET)的疗效,并评估其安全性。方法回顾性分析2011年1月—2017年12月在江苏省人民医院行直肠ESD治疗、经病理及免疫组织化学确诊为RNET的80例患者(91处病变)的临床资料,并对患者进行随访。结果所有病变均为完整切除病灶。有症状的患者术后3天~2月症状均有不同程度缓解,无严重术后并发症,标本切缘阳性率20.88%(19/91),切缘可疑阳性率35.16%(32/91)。切除标本最大长径20 mm。单因素分析中,肿瘤长径≥10 mm、肿瘤处于G2级与切缘可疑阳性及阳性相关(P<0.05)。肿瘤处于G2级为切缘可疑阳性及阳性的独立危险因素。仅有1例患者术前证实为RNET。中位随访时间34月,复发率4.40%(4/91)。结论ESD在治疗直径<20 mm的G1级和G2级的RNET患者中具有良好疗效。对于ESD术后显示切缘阳性及可疑阳性的RNET患者,可密切随访暂不实施其他治疗。     

Differential diagnosis of diarrhoea in patients with neuroendocrine tumours:A systematic review

BACKGROUND Approximately 20% of patients with neuroendocrine tumours(NETs) develop carcinoid syndrome(CS),characterised by flushing and diarrhoea.Somatostatin analogues or telotristat can be used to control symptoms of CS through inhibition of serotonin secretion.Although CS is often the cause of diarrhoea among patients with gastroenteropancreatic NETs(GEP-NETs),other causes to consider include pancreatic enzyme insufficiency(PEI),bile acid malabsorption and small intestinal bacterial overgrowth.If other causes of diarrhoea unrelated to serotonin secretion are mistaken for CS diarrhoea,these treatments may be ineffective against the diarrhoea,risking detrimental effects to patient quality of life.AIM To identify and synthesise qualitative and quantitative evidence relating to the differential diagnosis of diarrhoea in patients with GEP-NETs.METHODS Electronic databases(MEDLINE,Embase and the Cochrane Library) were searched from inception to September 12,2018 using terms for NETs and diarrhoea.Congresses,systematic literature review bibliographies and included articles were also hand-searched.Any study designs and publication types were eligible for inclusion if relevant data on a cause(s) of diarrhoea in patients with GEP-NETs were reported.Studies were screened by two independent reviewers at abstract and full-text stages.Framework synthesis was adapted to synthesise quantitative and qualitative data.The definition of qualitative data was expanded to include all textual data in any section of relevant publications.RESULTS Forty-seven publications(44 studies) were included,comprising a variety of publication types,including observational studies,reviews,guidelines,case reports,interventional studies,and opinion pieces.Most reported on PEI on/after treatment with somatostatin analogs;9.5%-84% of patients with GEP-NETs had experienced steatorrhoea or confirmed PEI.Where reported,14.3%–50.7% of patients received pancreatic enzyme replacement therapy.Other causes of diarrhoea reported in patients with GEP-NETs included bile acid malabsorption(80%),small intestinal bacterial overgrowth(23.6%-62%),colitis(20%) and infection(7.1%).Diagnostic approaches included faecal elastase,breath tests,tauroselcholic(selenium-75) acid(Se HCAT) scan and stool culture,although evidence on the effectiveness or diagnostic accuracy of these approaches was limited.Assessment of patient history or diarrhoea characteristics was also reported as initial approaches for investigation.From the identified evidence,if diarrhoea is assumed to be CS diarrhoea,consequences include uncontrolled diarrhoea,malnutrition,and perceived ineffectiveness of CS treatment.Approaches for facilitating differential diagnosis of diarrhoea include improving patient and clinician awareness of non-CS causes and involvement of a multidisciplinary clinical team,including gastroenterologists.CONCLUSION Diarrhoea in GEP-NETs can be multifactorial with misdiagnosis leading to delayed patient recovery and inefficient resource use.This systematic literature review highlights gaps for further research on prevalence of non-CS diarrhoea and suitability of diagnostic approaches,to determine an effective algorithm for differential diagnosis of GEP-NET diarrhoea.