Nordic guidelines 2021 for diagnosis and treatment of gastroenteropancreatic neuroendocrine neoplasms.

BACKGROUND: The diagnostic work-up and treatment of patients with gastroenteropancreatic (GEP) neuroendocrine neoplasms (NEN) has undergone major advances and new methods are introduced. Furthermore, an update of the WHO classification has resulted in a new nomenclature for GEP-NEN that is implemented in the clinic. AIM: These Nordic guidelines summarise the Nordic Neuroendocrine Tumour Group's current view on how to diagnose and treat GEP-NEN patients and aims to be useful in the daily practice for clinicians.

Chromogranin A and neuron-specific enolase in neuroblastoma: Correlation to stage and prognostic factors.

Chromogranin A (CgA) and neuron specific enolase (NSE) are important markers in adult neuroendocrine tumors (NET). Neuroblastoma (NB) has certain neuroendocrine properties. The aim of this study was to correlate blood concentrations of CgA, chromogranin B (CgB), and NSE to prognostic factors and outcome in children with NB. Blood samples from 92 patients with NB, 12 patients with benign ganglioneuroma (GN), 21 patients with non-NB solid tumors, 10 patients with acute leukemias, and 69 healthy children, were analyzed. CgA concentrations were higher in neonates vs. children older than one month in the control group (p < 0.0001), and in neonates with NB vs. the control group (p < 0.01). CgA and NSE concentrations were higher in patients with stages 3 and 4 disease (p < 0.05 and p < 0.05), in patients having tumors with amplification of MYCN (p < 0.05 and p < 0.001), or chromosome 1 p deletion (p < 0.05 and p < 0.05). NSE correlated to the tumor size at diagnosis (p < 0.001) and to tumor related death (p < 0.01) in NB. CgA and NSE concentrations were elevated in patients with NB and especially in those with advanced disease. Both CgA and NSE correlated to genetic markers, while only NSE correlated to primary tumor size and outcome in NB. We found that CgA and NSE are clinically valuable tumor markers in NB and they merit prospective clinical evaluations as such.

Surgical Treatment as a Principle for Patients with High-Grade Pancreatic Neuroendocrine Carcinoma: A Nordic Multicenter Comparative Study.

BACKGROUND: This study aimed to evaluate the role of surgery for patients with high-grade pancreatic neuroendocrine carcinoma (hgPNEC) in a large Nordic multicenter cohort study. Prior studies evaluating the role of surgery for patients with hgPNEC are limited, and the benefit of the surgery is uncertain. METHODS: Data from patients with a diagnosis of hgPNEC determined between 1998 and 2012 were retrospectively registered at 10 Nordic university hospitals. Kaplan-Meier curves were used to compare the overall survival of different treatment groups, and Cox-regression analysis was used to evaluate factors potentially influencing survival. RESULTS: The study registered 119 patients. The median survival period from the time of metastasis was 23 months for patients undergoing initial resection of localized nonmetastatic disease and chemotherapy at the time of recurrence (n = 14), 29 months for patients undergoing resection of the primary tumor and resection/radiofrequency ablation of synchronous metastatic liver disease (n = 12), and 13 months for patients with synchronous metastatic disease given systemic chemotherapy alone (n = 78). The 3-year survival rate after surgery of the primary tumor and metastatic disease was 69 %. Resection of the primary tumor was an independent factor for improved survival after occurrence of metastatic disease. CONCLUSIONS: Patients with resected localized nonmetastatic hgPNEC and later metastatic disease seemed to benefit from initial resection of the primary tumor. Patients selected for resection of the primary tumor and synchronous liver metastases had a high 3-year survival rate. Selected patients with both localized hgPNEC and metastatic hgPNEC should be considered for radical surgical treatment.

Nordic guidelines 2014 for diagnosis and treatment of gastroenteropancreatic neuroendocrine neoplasms.

BACKGROUND: The diagnostic work-up and treatment of patients with neuroendocrine neoplasms (NENs) has undergone major recent advances and new methods are currently introduced into the clinic. An update of the WHO classification has resulted in a new nomenclature dividing NENs into neuroendocrine tumours (NETs) including G1 (Ki67 index ≤ 2%) and G2 (Ki67 index 3-20%) tumours and neuroendocrine carcinomas (NECs) with Ki67 index > 20%, G3. Aim. These Nordic guidelines summarise the Nordic Neuroendocrine Tumour Group's current view on how to diagnose and treat NEN-patients and are meant to be useful in the daily practice for clinicians handling these patients.

Prevalence of metastases outside the liver and abdominal lymph nodes on 68Ga-DOTATOC-PET/CT in patients with small intestinal and pancreatic neuroendocrine tumours.

Metastases outside the liver and abdominal/retroperitoneal lymph nodes are nowadays detected frequently in patients with neuroendocrine tumours (NETs), owing to the high sensitivity of positron emission tomography (PET) with Gallium-68-DOTA-somatostatin analogues (68Ga-SSA) and concomitant diagnostic computed tomography (CT). Our aim was to determine the prevalence of extra-abdominal metastases on 68Ga-DOTATOC-PET/CT in a cohort of patients with small intestinal (Si-NET) and pancreatic NET (Pan-NET), as well as that of pancreatic metastasis in patients with Si-NET. Among 2090 patients examined by 68Ga-DOTATOC-PET/CT at two tertiary referral centres, a total of 1177 patients with a history of Si- or Pan-NET, were identified. The most recent 68Ga-DOTATOC-PET/CT report for each patient was reviewed, and the location and number of metastases of interest were recorded. Lesions outside the liver and abdominal nodes were found in 26% of patients (n = 310/1177), of whom 21.5% (255/1177) were diagnosed with Si-NET and 4.5% (55/1177) Pan-NET. Bone metastases were found in 18.4% (215/1177), metastases to Virchow's lymph node in 7.1% (83/1177), and lung/pleura in 4.8% (56/1177). In the subset of 255 Si-NET patients, 5.4% (41/255) manifested lesions in the pancreas, 1.5% in the breast (18/255), 1.3% in the heart (15/255) and 1% in the orbita (12/255). In Si-NET patients, the Ki-67 proliferation index was higher in those with ≥2 metastatic sites of interest, than with 1 metastatic site, (p <0.001). Overall, extra-abdominal or pancreatic metastases were more often found in patients with Si-NET (34%) than in those with Pan-NET (13%) (p <0.001). Bone metastases were 2.6 times more frequent in patients with Si-NET compared to Pan-NET patients (p <0.001). Lesions to the breast and orbita were encountered in almost only Si-NET patients. In conclusion, lesions outside the liver and abdominal nodes were detected in as many as 26% of the patients, with different prevalence and metastatic patterns in patients with Si-NET compared to Pan-NET. The impact of such metastases on overall survival and clinical decision-making needs further evaluation.

European Neuroendocrine Tumor Society (ENETS) 2024 guidance paper for the management of well-differentiated small intestine neuroendocrine tumours.

Both the incidence and prevalence of well-differentiated neuroendocrine tumours from the small intestine (Si-NET) are gradually increasing. Most patients have non-functioning tumours with subtle GI symptoms and tumours are often discovered incidentally by endoscopy or at advanced disease stages by imaging depicting mesenteric lymph node and /or liver metastases while around 30% of the patients present with symptoms of the carcinoid syndrome. Adequate biochemical assessment and staging including functional imaging is crucial for treatment-related decision-making that should take place in an expert multidisciplinary team setting. Preferably, patients should be referred to specialised ENETS Centres of Excellence or centres of high expertise in the field. This guidance paper provides the current evidence and best knowledge for the management of Si-NET grade (G) 1-3 following 10 key questions of practical relevance for the diagnostic and therapeutic decision making.

Long-term results of surgery for small intestinal neuroendocrine tumors at a tertiary referral center.

BACKGROUND: Small intestinal neuroendocrine tumors (SI-NETs) are uncommon, with an annual incidence of about 1 per 100,000 individuals. The primary tumor (PT) is generally small, but nevertheless the majority of patients have mesenteric lymph node metastases and liver metastases at diagnosis. Our aim was to identify prognostic factors for survival and to evaluate outcome after surgery in SI-NET patients. MATERIAL AND METHODS: We included 603 consecutive patients (325 men; age at diagnosis 63 ± 11 years [mean ± SD]) with histopathologically verified SI-NET, who were diagnosed between 1985 and 2010. Hospital charts were reviewed and were scrutinized for carcinoid heart disease (CHD), flush and/or diarrhea, proliferation by Ki-67 index, mesenteric lymph node metastases (m.lgllm), distant abdominal lymph node metastases (da.lgllm), liver tumor load (LTL), extra-abdominal metastases (EAM), locoregional resective surgery, as well as debulking of LTL, and adverse events after surgery. RESULTS: Median overall survival (OS) was 8.4 years; 5-year OS was 67%, and 5-year relative survival was 74%. Independent prognostic factors by univariate and multivariate analysis were age at diagnosis, CHD, m.lgllm, da.lgllm, LTL, EAM, peritoneal carcinomatosis (PC), and proliferation. Locoregional resective surgery was associated with increased survival on crude and multivariate analysis. The 30-day mortality in our institution after initial locoregional resective surgery was 0.5% (1/205). CONCLUSIONS: For the first time, m.lgllm and da.lgllm, LTL, PC, and EAM are demonstrated to be independent prognostic factors by multivariate analysis. Locoregional removal of the PT/m.lgllm. was a positive prognostic factor by crude and adjusted analysis and may influence survival.

Heterogeneity of Small Intestinal Neuroendocrine Tumors Metastasis: Biologic Patterns of a Series with Virchow's Node Involvement.

Small intestinal neuroendocrine tumors (SI-NETs) may rarely metastasize to the left supraclavicular lymph nodes, also known as Virchow's node metastasis (VM). Data on prevalence, prognostic significance, and clinical course of disease for SI-NET patients with VM is limited. In this retrospective analysis of 230 SI-NET patients treated at two tertiary referral centers, we found nine patients with VM (prevalence 3.9%). Among those, there were 5 females and median age at SI-NET and VM diagnosis was 61 and 65 years, respectively. Two patients had G1 tumors and five G2, while two tumors were of unspecified grade (median Ki67: 7%, range 2-15%). Four patients presented with synchronous VM, whereas five developed metachronous VM after a median of twenty-four months (range: 4.8-117.6 months). Hepatic metastases were present in seven patients, extrahepatic metastases (EM) in eight (six para-aortic distant lymph node metastases, one lung and one pancreatic metastasis), whereas peritoneal carcinomatosis (PC) in two patients. We used a control group of 18 age- and sex-matched SI-NET patients from the same cohort with stage IV disease but no extra-abdominal metastases. There was no difference in best-recorded response to first line treatment according to RECIST 1.1 as well as progression-free survival (PFS) between patients with VM and those in the control group (Chi-square test p = 0.516; PFS 71.7 vs. 106.9 months [95% CI 38.1-175.8]; log-rank p = 0.855). In addition, median overall survival (OS) of SI-NET patients with VM did not differ from those in the control group (138.6 [95% CI 17.2-260] vs. 109.9 [95% CI 91.7-128] months; log-rank p = 0.533). In conclusion, VM, although relatively rare in patients with SI-NETs, is more often encountered in patients with G2 tumors and established distant para-aortic lymph node metastases. The presence of VM in SI-NET patients does not seem to impact patients' survival outcomes and treatment responses, when compared to age- and sex-matched SI-NET patients with stage IV disease confined in the abdomen.

Differentiated expression of somatostatin receptor subtypes in experimental models and clinical neuroblastoma.

BACKGROUND: Neuroblastoma (NB) is a solid tumor of childhood originating from the adrenal medulla or sympathetic nervous system. Somatostatin (SS) is an important regulator of neural and neuroendocrine function, its actions being mediated through five specific membrane receptors. The aim of this study was to investigate the expression of the different somatostatin receptors (SSTRs) in NB tumor cells that may form targets for future therapeutic development. PROCEDURE: Tumor specimens from 11 children with stage II-IV disease were collected before and/or after chemotherapy. Experimental tumors derived from five human NB cell lines were grown subcutaneously in nude mice. Expression of SSRTs, the neuroendocrine marker chromogranin A (CgA) and SS was detected by immunohistochemistry using specific antibodies. RESULTS: SSTR2 was detected in 90%, SSTR5 in 79%, SSTR1 in 74%, SSTR3 in 68% whereas SSTR4 was expressed in 21% of the clinical tumors. The experimental tumors expressed SSTRs in a high but variable frequency. All clinical tumors showed immunoreactivity for CgA but not for SS. CONCLUSION: The frequent expression of SSTRs indicates that treatment with unlabeled or radiolabeled SS analogs should be further explored in NB.

Adrenalectomy in ectopic Cushing's syndrome: A retrospective cohort study from a tertiary care centre.

Neuroendocrine neoplasms (NENs) causing ectopic Cushing's syndrome (ECS) are rare and challenging to treat. In this retrospective cohort study, we aimed to evaluate different approaches for bilateral adrenalectomy (BA) as a treatment option in ECS. Fifty-three patients with ECS caused by a NEN (35 females/18 men; mean ± SD age: 53 ± 15 years) were identified from medical records. Epidemiological and clinical parameters, survival, indications for surgery and timing, as well as duration of surgery, complications and surgical techniques, were collected and further analysed. The primary tumour location was thorax (n = 30), pancreas (n = 14) or unknown (n = 9). BA was performed in 37 patients. Median time from diagnosis of ECS to BA was 2 months (range 1-10 months). Thirty-two patients received different steroidogenesis inhibitors before BA to control hypercortisolaemia. ECS resolved completely after surgery in 33 patients and severe peri- or postoperative complications were detected in 12 patients. There were fewer severe complications in the endoscopic group compared to open surgery (p = .030). Posterior retroperitoneoscopic BA performed simultaneously by a two surgeon approach had the shortest operating time (p = .001). Despite the frequent use of adrenolytic treatment, BA was necessary in a majority of patients to gain control over ECS. Complication rate was high, probably as a result of the combination of metastatic disease and metabolic disorders caused by high cortisol levels. The two surgeon approach BA may be considered as the method of choice in ECS compared to other BA approaches as a result of fewer complications and a shorter operating time.

Assessment of hormonal levels as prognostic markers and of their optimal cut-offs in small intestinal neuroendocrine tumours grade 2.

PURPOSE: Small intestinal neuroendocrine tumours (siNETs) with a Ki-67 proliferation index between 3 and 20% belong to WHO grade 2. Response to treatment may be monitored by blood chromogranin A (CgA) and urine 5-hydroxyindoleacetic acid (5HIAA). The aim of this retrospective study was to investigate the prognostic value of baseline CgA and 5HIAA and of the early biochemical response to treatment, and to compare different cut-off values used in the literature. METHODS: A retrospective cohort study of 184 patients with siNET Grade 2 treated with somatostatin analogues (SSA), interferon-alpha (IFN) or peptide receptor radionuclide therapy (PRRT). RESULTS: Baseline CgA was a statistically significant prognostic marker for both cancer-specific survival (CSS) and progression-free survival (PFS). A cut-off of 5 × ULN (upper limit of normal) was best discriminative in most cases, but 2 × ULN discriminated better for SSA. Baseline 5HIAA was a prognostic marker for CSS in treatment with IFN and PRRT, but not for single SSA. Early changes of CgA and 5HIAA correlated well with CSS (HR 3.18, 95% CI 1.82-5.56 and HR 1.47, 95% CI 1.16-1.86) and PFS (HR 3.08, 95% CI 1.86-5.10 and HR 1.37, 95% CI 1.11-1.68) for SSA, but not for PRRT. CONCLUSIONS: Baseline CgA and to a lesser extent 5HIAA are associated with CSS irrespective of treatment used, and with PFS after PRRT, and 5 × ULN provides best discrimination in many, but not all, cases. Early reductions of CgA and 5HIAA are prognostic for treatment with SSA, but not PRRT.

Nordic Guidelines 2010 for diagnosis and treatment of gastroenteropancreatic neuroendocrine tumours.

The diagnostic work-up and treatment of patients with neuroendocrine tumours has undergone a major change during the last decade. New diagnostic possibilities and treatment options have been developed. These Nordic guidelines, written by a group with a major interest in the subject, summarises our current view on how to diagnose and treat these patients. The guidelines are meant to be useful in the daily practice for clinicians handling patients with neuroendocrine tumours.

Multiple hormone secretion may indicate worse prognosis in patients with ectopic Cushing's syndrome.

PURPOSE: Ectopic Cushing's syndrome (ECS) caused by an ACTH secreting neuroendocrine neoplasm (NEN) is a rare and challenging condition. We aimed to detect predictive and prognostic parameters for ECS patients identified from a retrospective, comprehensive cohort of NENs treated at a tertiary referral center. METHODS: Medical records of 886 patients with NENs were reviewed. We identified 51 patients with ECS (33 females/18 men); mean age 52 ± 15 years (SD). Clinical parameters including symptoms, biochemical markers, and survival were extracted and further analyzed. RESULTS: The primary tumor was located in the thorax (n = 28) or pancreas (n = 15) or was of unknown primary origin (n = 8). In 30 patients, tumor and ECS were diagnosed simultaneously. In 12 patients, the NEN diagnosis preceded ECS development, with a median time of 43.5 months (range: 9-96), and 10 of these showed radiological tumor progression at ECS diagnosis. Twenty-one patients had multiple hormone secretion, which correlated with shorter overall survival (OS), p = 0.012 (HR 2.4 (95% CI 1.2-4.9)), as did high morning cortisol, p = 0.037 (HR 2.3 (1.0-5.2)), higher tumor grade, p = 0.044 (HR 2.3 (1.0-5.1)), and diabetes, p = 0.050 (HR 2.4 (1.0-6.0)). CONCLUSIONS: Multiple hormone secretion, high morning cortisol, higher tumor grade, and diabetes were correlated with shorter OS. Development of ECS in patients with a non-functioning NEN may indicate tumor progression. Multiple hormone secretion should be considered as a bad prognostic sign in ECS patients and should lead to intensified clinical management.

Candidate protein biomarkers in pancreatic neuroendocrine neoplasms grade 3.

Pancreatic neuroendocrine neoplasms (PanNENs) are rare tumours that compose 1-2% of all pancreatic tumours. Patients with metastatic grade 3 neoplasia are usually treated with chemotherapy but have a poor progression-free and overall survival. According to the WHO 2017 classification, they are divided into neuroendocrine tumours (NETs) G3 and neuroendocrine carcinomas (NECs). Despite the new classification, new diagnostic and prognostic biomarkers are needed to sub-categorise the patients and to help guide therapy decisions. Blood from 42 patients and 42 healthy controls were screened for the presence of 92 proteins with the Immuno-Oncology panel using the Proximity Extension Assay provided by Olink Biosciences. Immunohistochemical staining of FAS ligand (FASLG) was performed on 16 patient tumour specimens using a commercial antibody. Fifty-four out of 87 evaluable proteins differed significantly in concentration between blood from patients and blood from healthy controls. FASLG was the only protein for which the concentration in blood was significantly lower in patients compared to controls and the levels correlated negatively to Ki-67 index. Seven of 14 evaluable PanNEN G3 specimens showed FASLG immunoreactivity in the tumour cells while there was scattered immunoreactivity in immune cells. Positive FASLG immunoreactivity correlated to well-differentiated morphology. FASLG concentration in blood was significantly lower in patients with pancreatic NENs G3 compared to controls, and the expression in tumour tissue was variable. Furthermore, FASLG was negatively correlated to Ki-67 and was more frequently expressed in well-differentiated tumours. Taken together, these results may suggest a role of FASLG in PanNENs.

Synaptic Vesicle Protein 2 and Vesicular Monoamine Transporter 1 and 2 Are Expressed in Neuroblastoma.

Neuroblastoma (NB), the most common extracranial cancer in childhood, exhibits neuroendocrine (NE) differentiation. Two well-established NE markers, chromogranin A (CgA) and synaptophysin (syn), are used in the histopathological diagnostics. Our aims were to explore if the NE markers synaptic vesicle protein 2 (SV2) and vesicular monoamine transporter 1 (VMAT1) and 2 (VMAT2) also are expressed in human NB and if so, evaluate their usefulness in NB histopathological diagnostics. Tumor specimens from 21 NB patients, before and/or after chemotherapy, were immunostained for CgA, syn, SV2, VMAT1, and VMAT2. Clinical data was extracted from patients' records. SV2 was highly expressed in NB, as was CgA while syn was less frequently expressed compared to the other two. Both VMATs were expressed in several NB, VMAT2 in more cases than VMAT1 and its expression was similar to syn. Chemotherapy did not affect the immunoreactivity in an obvious way. SV2 was highly expressed in NB and can thus be useful marker in NB diagnostics. VMAT1 and VMAT2 were also expressed in NB but similar to syn less reliable as tumor markers.

Diagnostic ultrasound-guided cutting needle biopsies in neuroblastoma: A safe and efficient procedure.

BACKGROUND: Neuroblastoma (NB) is the most common extracranial solid tumor of childhood and accounts for 15% of deaths in pediatric oncology. Apart from the clinical stage at diagnosis, molecular factors are important for the characterization of the tumor and for decision on adequate treatment. Pretreatment diagnosis and molecular profiling are based on analysis of a tumor sample, obtained either by fine needle aspiration cytology (FNAC), cutting needle biopsy or open surgical biopsy. The method used depends on local tradition and routines. Ultrasound-guided cutting needle biopsy (UCNB) has been used at the Uppsala University Hospital since 1988 for diagnosis of pediatric solid tumors. PROCEDURES: Medical records of 29 patients with NB who underwent pretreatment, diagnostic, ultrasound-guided needle biopsy were reviewed. Information extracted from the patients' records included: age at diagnosis, gender, tumor site, clinical stage, molecular profiling made on biopsies (e.g. MYCN status, ploidy and chromosomal aberrations), and UCNB complications (i.e. bleeding, pain, or anesthesiologic complications). RESULTS: A total of 34 UCNBs were performed in the 29 patients. Repeated biopsies were done in three patients. UCNB was diagnostic in 90% (26/29). A complete molecular profiling was obtained in all UCNBs after 2008. Two patients (7%) developed a significant bleeding and two (7%) needed analgesics following UCNB. Neither infection nor tumor growth in the needle tract was observed. There were no anesthesiologic complications. CONCLUSIONS: UCNB is reasonably safe in patients with NB and usually gives a sufficient amount of tumor tissue for a histological diagnosis, molecular profiling, and biobank storage.

Measurements of secretogranins II, III, V and proconvertases 1/3 and 2 in plasma from patients with neuroendocrine tumours.

INTRODUCTION: Chromogranin (Cg) and secretogranin (Sg) are members of the granin family of proteins, which are expressed in neuroendocrine and nervous tissue. In recent publications we have presented generation of region-specific antibodies against CgA and CgB and also development of several region-specific radioimmunoassays for measurements of specific parts of the Cgs. In this study we describe generation of antibodies against SgII, SgIII, SgV and the proconvertases PC1/3 and PC2 and development of radioimmunoassays for measurements of these proteins. MATERIALS AND METHODS: Peptides homologous to defined parts of the secretogranin and proconvertase molecules were selected and synthesised. Antibodies were raised, radioimmunoassays were developed and circulating levels of the proteins in plasma samples from 22 patients with neuroendocrine tumours were measured in the assays. RESULTS: Increased plasma concentrations were recorded in 11, 4 and 3 of the patients with the SgII 154-165 (N-terminal secretoneurin), the SgII 172-186 (C-terminal Secretoneurin) and the SgII 225-242 assays respectively. The SgIII, SgV, PC1/3 and PC2 assays failed to detect increased concentrations in any of the patients. CONCLUSION: Increased concentrations of SgII, especially the N-terminal part of secretoneurin could be measured in plasma from patients with endocrine pancreatic tumours and in this case this assay was quite comparable to measurements of CgA and CgB. Even though secretoneurin was not as frequently increased as CgA and CgB in patients with carcinoid tumours or pheochromocytoma it may be a useful marker for endocrine pancreatic tumours.

Temozolomide as monotherapy is effective in treatment of advanced malignant neuroendocrine tumors.

PURPOSE: A retrospective analysis of the toxicity and efficacy of temozolomide in advanced neuroendocrine tumors. EXPERIMENTAL DESIGN: Thirty-six patients with advanced stages of neuroendocrine tumor (1 gastric, 7 thymic and 13 bronchial carcinoids, 12 pancreatic endocrine tumors, 1 paraganglioma, 1 neuroendocrine foregut, and 1 neuroendocrine cecal cancer) were treated with temozolomide (200 mg/m(2)) for 5 days every 4 weeks. Patients had previously received a mean of 2.4 antitumoral medical regimens. Tumor response was evaluated radiologically according to the Response Evaluation Criteria in Solid Tumors every 3 months on an intent-to-treat basis. The circulating tumor marker plasma chromogranin A was also assessed. The expression of O(6)-methylguanine DNA methyltransferase, an enzyme implicated in chemotherapy resistance, was studied by immunohistochemistry (n=23) and compared with response to temozolomide. RESULTS: Median overall time to progression was 7 months (95% confidence interval, 3-10). Radiologic response was seen in 14% of patients and stable disease in 53%. Side effects were mainly hematologic; 14% experienced grade 3 or 4 thrombocytopenia (National Cancer Institute toxicity criteria). Ten patients had tumors with O(6)-methylguanine DNA methyltransferase immunoreactivity in <10% of nuclei, whereas four patients showed radiologic responses. CONCLUSIONS: Temozolomide as monotherapy had acceptable toxicity and antitumoral effects in a small series of patients with advanced malignant neuroendocrine tumors and four of these showed radiologic responses.

Intravenous versus oral etoposide: efficacy and correlation to clinical outcome in patients with high-grade metastatic gastroenteropancreatic neuroendocrine neoplasms (WHO G3).

High-grade gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs, G3) are aggressive cancers of the digestive system with poor prognosis and survival. Platinum-based chemotherapy (cisplatin/carboplatin + etoposide) is considered the first-line palliative treatment. Etoposide is frequently administered intravenously; however, oral etoposide may be used as an alternative. Concerns for oral etoposide include decreased bioavailability, inter- and intra-patient variability and patient compliance. We aimed to evaluate possible differences in progression-free survival (PFS) and overall survival (OS) in patients treated with oral etoposide compared to etoposide given as infusion. Patients (n = 236) from the Nordic NEC study were divided into three groups receiving etoposide as a long infusion (24 h, n = 170), short infusion (≤ 5 h, n = 33) or oral etoposide (n = 33) according to hospital tradition. PFS and OS were analyzed with Kaplan-Meier (log-rank), cox proportional hazard ratios and confidence intervals. No statistical differences were observed in PFS or OS when comparing patients receiving long infusion (median PFS 3.8 months, median OS 14.5 months), short infusion (PFS 5.6 months, OS 11.0 months) or oral etoposide (PFS 5.4 months, OS 11.3 months). We observed equal efficacy for the three administration routes suggesting oral etoposide may be safe and efficient in treating high-grade GEP-NEN, G3 patients scheduled for cisplatin/carboplatin + etoposide therapy.