Outcomes Of Neuroendocrine Tumors Research Articles

Radio-Guided Surgery with a New-Generation β-Probe for Radiolabeled Somatostatin Analog, in Patients with Small Intestinal Neuroendocrine Tumors.

Radio-guided surgery (RGS) holds promise for improving surgical outcomes in neuroendocrine tumors (NETs). Previous studies showed low specificity (SP) using γ-probes to detect radiation emitted by radio-labeled somatostatin analogs. We aimed to assess the sensitivity (SE) and SP of the intraoperative RGS approach using a β-probe with a per-lesion analysis, while assessing safety and feasibility as secondary objectives. This prospective, single-arm, single-center, phase II trial (NCT05448157) enrolled 20 patients diagnosed with small intestine NETs (SI-NETs) with positive lesions detected at 68Ga-DOTA-TOC positron emission tomography/computed tomography (PET/CT). Patients received an intravenous injection of 1.1 MBq/Kg of 68Ga-DOTA-TOC 10min prior to surgery. Invivo measurements were conducted using a β-probe. Receiver operating characteristic (ROC) analysis was performed, with the tumor-to-background ratio (TBR) as the independent variable and pathology result (cancer vs. non-cancer) as the dependent variable. The area under the curve (AUC), optimal TBR, and absorbed dose for the surgery staff were reported. The intraoperative RGS approach was feasible in all cases without adverse effects. Of 134 specimens, the AUC was 0.928, with a TBR cut-off of 1.35 yielding 89.3% SE and 86.4% SP. The median absorbed dose for the surgery staff was 30 µSv (range 12-41 µSv). This study reports optimal accuracy in detecting lesions of SI-NETs using the intraoperative RGS approach with a novel β-probe. The method was found to be safe, feasible, and easily reproducible in daily clinical practice, with minimal radiation exposure for the staff. RGS might potentially improve radical resection rates in SI-NETs. 68Ga-DOTATOC Radio-Guided Surgery with β-Probe in GEP-NET (RGS GEP-NET) [NCT0544815; https://classic. gov/ct2/show/NCT05448157 ].

Addition of Peptide Receptor Radiotherapy to Immune Checkpoint Inhibition Therapy Improves Outcomes in Neuroendocrine Tumors.

Neuroendocrine tumors (NETs) are often diagnosed in advanced stages. Despite the advances in treatment approaches, including somatostatin analogs and peptide receptor radionuclide therapy (PRRT), these patients have no curative treatment option. Moreover, immunotherapy often yields modest results in NETs. We investigated whether combining PRRT using [177Lu]DOTATATE and immune checkpoint inhibition therapy improves treatment response in NETs. Methods: A gastroenteropancreatic NET model was generated by subcutaneous implantation of human QGP-1 cells in immune-reconstituted NOD.Cg-Prkdcscid Il2rgtm1Wjl /SzJ mice engrafted with human peripheral blood mononuclear cells (n = 96). Mice were randomly assigned to receive pembrolizumab (anti-PD1), [177Lu]DOTATATE (PRRT), simultaneous anti-PD1 and PRRT (S-PRRT), anti-PD1 on day 0 followed by PRRT on day 3 (delayed PRRT [D-PRRT]), PRRT on day 0 followed by anti-PD1 (early PRRT [E-PRRT]), or vehicle as control (n = 12/group). Human granzyme-B-specific [68Ga]NOTA-hGZP PET/MRI was performed before and 6 d after treatment initiation, as an indicator of T-cell activation. Response to treatment was based on tumor growth over 21 d and on histologic analyses of extracted tissues on flow cytometry for T cells, hematoxylin and eosin staining, and immunohistochemical staining. Results: [68Ga]NOTA-hGZP PET/MRI showed significantly increased uptake in tumors treated with E-PRRT, S-PRRT, and anti-PD1 on day 6 compared with baseline (SUVmax: 3.36 ± 0.42 vs. 0.73 ± 0.23; 2.36 ± 0.45 vs. 0.76 ± 0.30; 2.20 ± 0.20 vs. 0.72 ± 0.28, respectively; P < 0.001), whereas no significant change was seen in PET parameters in the D-PRRT, PRRT, or vehicle groups (P > 0.05). Ex vivo analyses confirmed the PET results showing the highest granzyme-B levels and T cells (specifically CD8-positive effector T cells) in the E-PRRT group, followed by the S-PRRT and anti-PD1 groups. Tumor growth follow-up showed the most significant tumor size reduction in the E-PRRT group (baseline to day 21, 205.00 ± 30.70 mm3 vs. 78.00 ± 11.75 mm3; P = 0.0074). Tumors showed less growth reduction in the PRRT, D-PRRT, and S-PRRT groups than in the E-PRRT group (P < 0.0001). The vehicle- and anti-PD-1-treated tumors showed continued growth. Conclusion: Combination of PRRT and anti-PD1 shows the most robust inflammatory response to NETs and a better overall outcome than immune checkpoint inhibition or PRRT alone. The most effective regimen is PRRT preceding anti-PD1 administration by several days.

Long-term clinical outcomes of endoscopic submucosal dissection in rectal neuroendocrine tumors based on resection margin status: a real-world study.

Endoscopic submucosal dissection (ESD) has been widely adopted in treating rectal neuroendocrine tumors (NETs). However, clinical outcomes in rectal NETs after ESD with different resection margin status remain scanty, particularly in patients with positive resection margins. This study aimed to evaluate the long-term clinical outcomes of ESD in rectal NET based on the resection margin status. This retrospective study included 436 patients diagnosed with rectal NET who had undergone ESD. Clinical data, including age, sex, tumor size, stage, invasion, and the resection margin status, were collected. Further, the patients were assessed for complications, recurrence, distant metastasis, and long-term outcomes. Among all 436 patients, 395 patients had their primary ESD in our hospital. Complete resection was achieved in 319 patients. Patients who did not achieve complete resection opted for follow-up (n = 73), salvage surgery (n = 1) and salvage ESD (n = 2). Another 41 had their primary ESD in other hospital with incomplete resection and had salvage ESD in our hospital. All 436 patients had a median follow-up period of 61.4months (range 33.4-125.3months). During the follow-up period, two patients developed recurrences, while three patients developed metastasis. There were no significant differences in the 5-year progression-free survival and overall survival between patients with incomplete resection opting for follow-up compared to the other two groups (P = 0.5/0.8). However, the complication rates were significantly higher in patients who received salvage ESD. This study demonstrated that positive resection margins have no influence on survival in patients with rectal NET treated using ESD.

Abstract 2253: Comparison of genomic alterations in neuroendocrine tumors originated from different primary sites

Abstract Background: Neuroendocrine tumors (NETs) are heterogeneous, relatively rare tumors derive from neuroendocrine system. Currently, limited therapeutic strategies are available for NETs. Next-generation sequencing (NGS) and target gene-based precision therapy have shown promising efficacy in many tumors, but fare in NETs. Several reports illustrated that the primary sites of NETs were significantly bound up with the clinical response and prognosis. However, characteristics of their genomic alterations are insufficiency nowadays. Methods: A cohort of 94 Chinese NET patients were recruited, and the FFPE tumor tissues and matching blood samples from different primary sites were collected. Targeted next generation sequencing (NGS) of 450 genes was performed in OrigiMed (Shanghai, China) with a College of American Pathologists (CAP) accredited and Clinical Laboratory Improvement Amendments (CLIA) certified laboratory. Results: In all patients, the top 5 most-frequently aberrant genes were TP53 (46.8%, 44/94), RB1 (23.4% 22/94), MEN1 (20.2%, 19/94), KRAS (11.7%, 11/94) and ATRX (9.6%, 9/94). The enrolled NETs contain 7 different primary sites, namely, 37 pancreatic NETs (PNETs), 16 hepatic NETs (HNETs), 11 gastric NETs (GNETs), 10 gallbladder NETs (GB-NETs), 8 esophageal NETs (ENETs), 7 colorectal NETs (CNETs), and 5 small intestine NETs (SI-NETs). Based on origin sites, TP53 is the most widely distributed mutant gene in all sites except for PNETs (Ranked 3rd), while RB1 mutations were significantly higher in ENETs (75.0%, 6/8), GB-NETs (60.0%, 6/10) and GNETs (36.4%, 4/11). Other higher -frequency mutated genes among different sites showed greatly dissimilarity (MEN1, ATRX and DAXX in PNETs; FAT3, MAX, MUC16, GATA4 and OBSCN in HNETs; APC, KRAS and PTEN in GNETs; TERT, ERBB2 and YES1 in GB-NETs; LRP1B and FBXW7 in ENETs; APC, ADGRA2 and FGFR1 in CNETs; NF1 in SI-NETs). Furthermore, signaling pathways involved in potential drug-target genes were analyzed. Results revealed 16.0% (15/94) patients with aberrations in PI3K/AKT/mTOR pathway, 11.7% (11/94) in Cell-Cycle pathway, 9.6% (9/94) in HRD pathway, 9.6% (9/94) in FGF pathway and 16.0% (15/94) in other cancer-related genes (ERBB2, VHL, MET etc.). Conclusions: This study reveals the genomic alteration characteristics of NETs from different primary sites. The profiles obtained in our study may provide evidences for further targeted therapy to improve outcomes of Chinese NETs. Citation Format: Qiyun Tang, Ye Tian, Xiaolin Li, Jian'an Bai, Min Liu, Ping Hu, Shanshan Zhang, Zanmei Xu, Yueting Qu, Aodi Wang. Comparison of genomic alterations in neuroendocrine tumors originated from different primary sites [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2253.

Factors associated with worse outcomes for colorectal neuroendocrine tumors in radical versus local resections.

Colorectal neuroendocrine tumors (NETs) are the most common NETs of the gastrointestinal tract. Due to the rarity, colorectal NETs are understudied and are not clearly understood. Our study sought to identify the factors associated with worse outcomes for colorectal NETs following resection. We identified patients diagnosed with colorectal NETs [2004-2014] who underwent resection from the National Cancer Data Base. Non-NETs were excluded. Overall survival (OS) was evaluated using the Kaplan Meier method. Cox proportional hazards and logistic regression models were used to assess factors associated with radical versus local resection, OS and LOS. A total of 7,967 colon and 11,929 rectal NETs were analyzed. The majority of colon (93.4%) and rectal (89.1%) NETs underwent radical and local resection respectively. The 5-year OS was 69% and 92% for colon and rectal NETs respectively. Older age (OR 1.45, CI 1.37-1.53) and clinical stage 4 (OR 9.91, CI 4.56-21.52) were associated with higher odds for colonic radical resection. Lowest median income quartile (OR 1.41, CI 1.21-1.64) and African Americans (OR 1.26, CI 1.07-1.49) experienced higher mortality for colon and rectal NETs respectively. Racial minority and low-income patients experience worse outcomes for colorectal NETs following resection.

Outcomes of Endoscopic Submucosal Dissection for Subepithelial Lesions Localized Within the Submucosa, Including Neuroendocrine Tumors: A Multicenter Prospective Study.

Endoscopic submucosal dissection (ESD) seems to be a reasonable option for gastrointestinal subepithelial lesions (SELs) localized within the submucosa. Indications for ESD include small neuroendocrine tumors (NETs) and indeterminate SELs. However, the prospective data regarding ESD and surveillance remain unclear. This study was performed to prospectively investigate the outcomes of ESD, including organ-specific outcomes and the mid-term prognosis. This prospective multicenter study included 57 patients who underwent ESD for SELs localized within the submucosa [definite NETs (n = 42) and indeterminate SELs (n = 15)]. The efficacy and safety of ESD were evaluated in the whole cohort and in subgroups (NETs and indeterminate SELs). All patients were followed up. The rates of en bloc resection, curative resection, and complications were 98.2%, 66.7%, and 7.7% for the overall population (n=57); 100%, 61.9%, and 2.4% for NETs (n=42); and 93.3%, 80.0%, and 20.0% for indeterminate SELs (n=15), respectively. The rates of curative resection for NETs were poorer in the stomach (20%, n=5) and duodenum (33%, n=3) than in the rectum (71%, n=34). Including 11 of 16 patients with NETs who underwent a conservative approach resulting in non-curative resection, no patients developed tumor recurrence during the follow-up period (median, 24.5 months; range, 1-60 months). ESD followed by surveillance demonstrated acceptable mid-term outcomes for non-curative NETs. ESD can be an efficient therapy for SELs localized within the submucosa. However, gastric and duodenal ESD for NETs may be limited in terms of its curative and technical aspects. Clinicians should be aware of the potential complications of ESD for indeterminate SELs.

Elderly Patients with Metastatic Neuroendocrine Tumors Are Undertreated and Have Shorter Survival: The LyREMeNET Study

Introduction: The incidence of neuroendocrine tumors (NETs) is rising, especially in elderly patients. The elderly cancer population presents considerable challenges, yet little is known about the characteristics, treatment patterns, and outcomes of metastatic NET (mNET) patients. Methods: The Lyon Real-life Evidence in Metastatic NeuroEndocrine Tumors study (LyREMeNET, NCT03863106) included consecutive mNET patients, diagnosed between January 1990 and December 2017. The exclusion criteria were nonmetastatic NET, poorly differentiated neuroendocrine carcinoma, and mixed neuroendocrine-nonneuroendocrine neoplasms. We aimed to compare patients ≥70 years old to patients <70 years old. Results: A total of 866 patients were included, 198 (23%) were ≥70 years old. There was no significant difference in characteristics except that elderly patients had synchronous metastasis more frequently. Elderly patients received significantly fewer treatments (median of 2.0 vs. 3.0 lines, respectively, p < 0.0001), were significantly less frequently treated by chemotherapy (32 vs. 54%), targeted therapy (16 vs. 30%), peptide receptor radionuclide therapy (5 vs. 16%), and they underwent significantly less frequently locoregional intervention. Median overall survival was significantly shorter in elderly patients (5.2 vs. 9.6 years). The most frequent cause of death was related to disease progression (71%). Multivariate analysis found that, after adjustment for tumor location, tumor grade, and number of metastatic sites, age remained significantly associated with overall survival (HR 1.66, 95% CI 1.26–2.18), indicating a poorer survival in patients ≥70 years old in comparison with younger patients (p = 0.0003). Conclusion: Patients ≥70 years old have a worse survival, die frequently from their disease, and are undertreated compared to younger patients.

Typical carcinoids, goblet cell carcinoids, mixed adenoneuroendocrine carcinomas, neuroendocrine carcinomas and adenocarcinomas of the appendix: a comparative analysis of survival profile and predictors.

Goblet cell carcinoids (GCC) and other atypical neuroendocrine tumors (NET) of the appendix as well as appendiceal adenocarcinoma are usually managed with the same algorithm as colon cancers. This study investigates clinicopathological features that are predictive of survival outcomes for appendiceal NET and adenocarcinoma. Survival profiles for the histologic subtypes of appendiceal NET and adenocarcinoma were compared. A retrospective review of appendiceal NET and adenocarcinoma for patients who are 18 years and above in the SEER database from 2010 to 2014. Females outnumbered males in a 1.3 to 1 ratio in the NET subgroup and 1.1 to 1 ratio in the adenocarcinoma group. The mean age at diagnosis for all NET was 50.3±17 years while that of adenocarcinomas was 60.8±14.1 years. Within the NET subgroups, the mean ages for typical carcinoids (TC), GCC, NEC and MANEC were 42.9±17.3, 56.7±13.7, 45.6±17.4 and 59.7±12.8 years, respectively. Overall survival for adenocarcinoma was 86.3%, 73.5%, 65.7%, and 57.6% for 1-, 2-, 3- and 4-year OS, respectively. For NET, TC showed better survival profile with 1- and 4-year overall survival of 97.4% and 95.7%, respectively while MANEC had the worst survival outcome with 1- and 4-year OS of 88.6% and 62.2%, respectively. GCC had a better 1-year OS compared to NEC (95.5% versus 92.9%) but showed slightly worse 4-year OS (82% versus 84.8%). Age at diagnosis (HR 1.03), African-American race (HR 1.47) and stage IV disease (HR 9.58) were independent predictors of survival for appendiceal adenocarcinoma. For NET, advanced age at diagnosis, advanced disease stage and the African-American race were identified as negative independent predictors of survival. While prior studies have suggested that atypical NET (GCC, NEC and MANEC) are more likely to present at more advanced stages, this study showed that most cases of GCC, MANEC and NEC were diagnosed at stages I and II. Appendiceal adenocarcinoma, on the other hand, presented mostly at stage IV. With respect to OS, atypical histologic subtypes of NET have worse outcome compared to TC. Although better OS was noted for GCC, NEC and MANEC when compared to adenocarcinoma, this benefit was lost in stage IV disease where adenocarcinoma recorded better 1- and 4-year OS. Prospective and randomized studies which provide granular details of treatment are needed to better define treatment algorithm for appendiceal NET.

Value of Tumor Growth Rate (TGR) as an Early Biomarker Predictor of Patients' Outcome in Neuroendocrine Tumors (NET)-The GREPONET Study.

Tumor growth rate (TGR; percent size change per month [%/m]) is postulated to be an early radiological biomarker to overcome limitations of RECIST. This study aimed to assess the impact of TGR in neuroendocrine tumors (NETs) and potential clinical and therapeutic applications. Patients (pts) with advanced grade (G) 1/2 NETs from the pancreas or small bowel initiating systemic treatment (ST) or watch and wait (WW) were eligible. Baseline and follow-up scans were retrospectively reviewed to calculate TGR at pretreatment (TGR0), first follow-up (TGRfirst), and 3(±1) months of study entry (TGR3m). Out of 905 pts screened, 222 were eligible. Best TGRfirst (222 pts) cutoff was 0.8 (area under the curve, 0.74). When applied to TGR3m (103 pts), pts with TGR3m <0.8 (66.9%) versus TGR3m ≥ 0.8 (33.1%) had longer median progression-free survival (PFS; 26.3 m; 95% confidence interval [CI] 19.5-32.4 vs. 9.3 m; 95% CI, 6.1-22.9) and lower progression rate at 12 months (7.3% vs. 56.8%; p = .001). WW (vs. ST) and TGR3m ≥ 0.8 (hazard ratio [HR], 3.75; 95% CI, 2.21-6.34; p < .001) were retained as factors associated with a shorter PFS in multivariable Cox regression. TGR3m (HR, 3.62; 95% CI, 1.97-6.64; p < .001) was also an independent factor related to shorter PFS when analysis was limited to pts with stable disease (81 pts). Out of the 60 pts with TGR0 data available, 60% of pts had TGR0 < 4%/month. TGR0 ≥ 4 %/month (HR, 2.22; 95% CI, 1.15-4.31; p = .018) was also an independent factor related to shorter PFS. TGR is an early radiological biomarker able to predict PFS and to identify patients with advanced NETs who may require closer radiological follow-up. Tumor growth rate at 3 months (TGR3m) is an early radiological biomarker able to predict progression-free survival and to identify patients with advanced neuroendocrine tumors who may require closer radiological follow-up. It is feasible to calculate TGR3m in clinical practice and it could be a useful tool for guiding patient management. This biomarker could also be implemented in future clinical trials to assess response to therapy.

Prognostic and predictive role of the PI3K-AKT-mTOR pathway in neuroendocrine neoplasms.

Neuroendocrine neoplasms (NENs) are considered a heterogeneous and rare entity. Its natural history is influenced by multiple clinicopathological characteristics, which guide the management of these patients. The development of molecular biology reveals that the PI3K-AKT-mTOR pathway plays a relevant role in tumorigenesis and progression of NENs. Mammalian target of rapamycin (mTOR) inhibitors, targeted agents that block this pathway, has improved outcomes in neuroendocrine tumors (NETs). Different therapeutic approaches, such as somatostatin analogs, chemotherapy, peptide receptor radionuclide therapy, and targeted agents, have shown benefits in the treatment of NETs. However, there are not any established prognostic or predictive biomarkers to select the best therapy option to individualize treatment. Although a relation between alterations in the PI3K-AKT-mTOR pathway and clinical outcomes has not been found, these anomalies are considered attractive biomarkers. Additional molecular analysis should be integrated in future clinical trials' design to identify potential predictive or prognostic biomarkers.

Clinical characteristics, risk factors and outcomes of asymptomatic rectal neuroendocrine tumors

Rectal neuroendocrine tumors (NET) are often asymptomatic and frequently discovered during health examinations. However, data on the risk factors of asymptomatic rectal NETs are lacking. We investigated the risk factors, clinical characteristics and outcomes of asymptomatic rectal NETs discovered during health screening. Asymptomatic subjects who underwent colonoscopy during routine health screening at a tertiary hospital from March 2009 to July 2014 were reviewed. Subjects with histologically confirmed rectal NETs were compared with healthy controls from the same population. Risk factors for rectal NETs were analyzed by multivariable analysis. Clinical outcomes of the resected NETs were also analyzed. A total of 21,706 Subjects underwent screening colonoscopy during the study period. 3417 were excluded from the study, and 180 rectal NET subjects were compared with 18,109 controls. Multivariable analysis showed that a previous history of malignancy (OR 2.960, 95% CI 1.673-5.237, p<0.001), hypertriglyceridemia (OR 1.482, 95% CI 1.046-2.100, p=0.027), higher fasting plasma glucose levels (OR 1.008, 95% CI 1.003-1.014, p=0.001) and higher carcinoembryonic antigen levels (OR 1.019, 95% CI 1.003-1.035, p=0.021) were significant risk factors while older age (OR 0.964, 95% CI 0.951-0.977, p<0.001) was a preventive factor. One hundred and sixty nine subjects had endoscopic resection, five were treated by local surgery and six by radical surgery. Complete resection was achieved in 152 subjects. There were three cases of positive lymph nodes and one metastasis. Histology revealed four lymphatic, five vascular and two cases of perineural invasion. One hundred and fifty seven subjects were followed up for at least 1year (median 38.6months, 12-84months). There were no recurrences during the follow-up period. Younger age, previous history of malignancy, higher fasting plasma glucose levels and hypertriglyceridemia are significantly associated with rectal NET risk.

Association Between Somatostatin Receptor Expression and Clinical Outcomes in Neuroendocrine Tumors.

Somatostatin receptors (SSTRs), products of gene superfamily SSTR1-5, are commonly expressed in neuroendocrine tumors (NETs). Somatostatin analogs (SSAs) bind to SSTRs and are used as therapeutic agents in patients with advanced NETs. We hypothesized that tumor SSTR expression status would be associated with clinical outcomes in NET. Expression of the 5 SSTRs was evaluated by immunohistochemistry, using tissue microarrays comprising 173 primary NETs, 24 matched metastases, and 22 metastatic NETs from 195 patients. Cox proportional hazards regression analysis was used to assess the association of SSTR expression status (high vs low) with clinical outcomes, adjusting for potential confounders. High expression of SSTR2 was associated with longer overall survival (OS) in the cohort overall (multivariate hazard ratio, 0.42; 95% confidence interval, 0.21-0.84; P = 0.013). In a subgroup of patients with metastatic small intestine NET treated with SSAs and evaluable for progression, SSTR2 expression was associated with both longer progression-free survival (PFS) and OS. No associations with PFS or OS were observed with expression of other SSTRs. Our study demonstrated that expression of SSTR2, but not other SSTRs, is associated with longer OS. In patients treated with SSAs, expression of SSTR2 is associated with longer PFS survival.

Therapeutic Dilemma: Prognostic Factors and Outcome for Neuroendocrine Tumors of the Cervix.

The aim of this study was to review treatment and outcomes for neuroendocrine tumors (NETs) of the cervix at a National Cancer Institute-designated Comprehensive Cancer Center. Data for women with NET of the cervix treated at our institution, since 1999, were collected. Progression-free survival (PFS) and overall survival (OS) were assessed with respect to age, tumor size, tobacco use, lymph node status, stage of disease, and type of treatment. Among 18 patients (median age, 44 years), 9 (50%) had tumors larger than 5 cm and advanced-stage disease (IB2-IV). Seven recurrences were noted (39%). Median PFS was not reached, and median OS was 72.2 months. Surgery was the only factor significantly associated with both PFS and OS (3-year PFS, 90% vs 30%, P = 0.01; 3-year OS: 89% vs 18%, P = 0.019). Age 40 years or younger and absence of lymph node metastases correlated significantly with PFS, with a trend toward improved OS. Recurrences were less likely with stage IA to IB1 compared with stages IB2 to IVA and IVB (hazards ratio, 0.33; P = 0.054), with median OS of 72.2, 19.2, and 7.4 months, respectively (P = 0.002). Although patients with tumors 4 cm or smaller had better outcomes, this factor did not reach statistical significance. Chemotherapy, radiation therapy, and tobacco use were not associated with survival. Neuroendocrine tumors of the cervix present at a relatively young age, with bulky tumors and advanced-stage disease. Surgery, younger age, smaller tumor size, early stage, and absence of lymph node involvement seem to be associated with improved survival. Nonetheless, optimal management is yet to be determined, and multimodality treatment is advocated.

Excellent prognosis following endoscopic resection of patients with rectal neuroendocrine tumors despite the frequent presence of lymphovascular invasion.

Endoscopic resection (ER) has been increasingly used for the treatment of rectal neuroendocrine tumors (NETs); however, only limited data are available on its long-term outcomes. This study analyzed the long-term outcomes of rectal NETs treated by ER and characterized potential risk factors for metastasis in these cases, with emphasis on lymphovascular invasion. We retrospectively analyzed the clinicopathological features and outcomes of 86 patients with 90 rectal NETs who had been treated by ER. Lymphovascular invasion was reevaluated using elastic-staining and double-staining immunohistochemistry. En bloc resection with tumor-free margins was achieved in 87 lesions (96.7%). The median tumor size was 5 mm (range 2-13), and all the lesions were confined to the submucosal layer. The Ki-67 index was less than 3% in all the lesions, which were therefore classified as NET G1. Elastic-staining and double-staining immunohistochemistry revealed the presence of lymphatic and venous invasion in 23 (25.6%) and 35 lesions (36.7%), respectively. Collectively, lymphatic and/or vascular invasion was identified in 42 lesions (46.7%). All cases were followed up without additional surgery, and no metastasis or recurrence was detected during the median follow-up period of 67.5 months. This study showed an excellent long-term prognosis following ER of patients with rectal NETs, confirming that ER is a valid treatment option for small rectal NETs. The present study also revealed highly prevalent lymphovascular invasion even in minute rectal NETs; this observation raises a question regarding its significance as a risk factor for metastasis.

Rural-urban disparities in incidence and outcomes of neuroendocrine tumors: A population-based analysis of 6271 cases.

Despite their rising incidence, neuroendocrine tumors (NETs) remain a poorly understood disease. Living in a rural area (RA) affects the incidence and outcomes of other types of cancer. This study compared the incidence and outcomes of NETs for patients in RAs and patients in urban areas (UAs). A population-based cohort study of patients with NETs in Ontario, Canada from 1994 to 2011 was conducted. An RA was defined as any community with a population < 10,000 and outside the commuting zone of a metropolitan area. Incidence, advanced stage at presentation, distant recurrence-free survival (dRFS), and overall survival (OS) were compared between patients who lived in RAs and patients who lived in UAs with univariate and multivariate regression analyses. The cohort included 6271 patients diagnosed with NETs, of whom 13.5% (n = 846) resided in RAs. The incidence of NETs was higher in RAs at 3.01 per 100,000 per year versus UAs at 2.82 per 100,000 per year (relative rate, 1.10; P = .04). RA living was not associated with an advanced stage at presentation (odds ratio, 1.15; 95% confidence interval, 0.96-1.38). Patients who lived in RAs had worse 10-year dRFS (62.8% vs 65.9%, P = .03) and OS (44.6% vs 48.8%, P = .004). RAs were independently associated with decreased OS (hazard ratio, 1.16; 95% confidence interval, 1.04-1.30). Patients are more commonly diagnosed with NETs in RAs, but they do not present at more advanced stages in comparison with patients diagnosed in UAs. Patients living in RAs experience worse cancer recurrence and OS, and this is possibly related to variations in socioeconomic status, rural environmental factors, and access to specialized health care.

Case report from a study investigating everolimus combined with paclitaxel and carboplatin in patients with advanced large cell neuroendocrine carcinoma of the lung (LCNEC)

Targeted therapies are discussed as an approach to improve outcome in neuroendocrine tumors of the lung. With current treatment options like platinum derivates and etoposide, large cell neuroendocrine carcinoma of the lung (LCNEC) patients have a poor prognosis.

The Oncofetal Protein IMP3: A Useful Marker to Predict Poor Clinical Outcome in Neuroendocrine Tumors of the Lung

We evaluated the expression of the oncofetal protein IMP3 in a series of neuroendocrine tumors of the lung, correlating our results with proliferating index Ki67 and with the expression of the two most studied stem cell markers in lung cancer, Nanog and Oct3/4. A total of 74 patients with a diagnosis of neuroendocrine tumor including 46 cases of typical carcinoid, nine cases of atypical carcinoids, 13 cases of large cell neuroendocrine carcinomas and six cases of small cell carcinomas were enrolled. IMP3 was expressed in 50% of small cell carcinomas, 84% of large cell neuroendocrine carcinomas, 55% of atypical carcinoids and 10% of typical carcinoids. IMP3-positive cases showed significantly decreased overall and disease-free survival time compared with IMP3-negative cases. Nanog was expressed in 50% of small cell carcinomas, 31% of large cell neuroendocrine carcinomas, 33% of atypical carcinoids and 15% of typical carcinoids, and 68% of IMP3-positive tumors were also enriched for Nanog expression. Conversely, Oct3/4 expression could not be detected in all the analyzed series. When combining Ki67 and IMP3 expression we demonstrated that all the cases with a Ki67 index higher than 4% were also IMP3-positive, and their simultaneous expression was a poor prognostic factor. IMP3 is a marker of poor outcome in lung neuroendocrine tumors; its correlation with Nanog expression suggest an implication of IMP3 in stem cell processes and its association with a Ki67 labeling index higher than 4% stratifies a subset of atypical carcinoids with a higher risk of recurrence and mortality.

Surveillance Strategy for Rectal Neuroendocrine Tumors According to Recurrence Risk Stratification

Rectal neuroendocrine tumors (NETs) have been increasing in incidence. However, the recommendations for disease surveillance after tumor resection have not been well established. We evaluated the long-term outcomes of rectal NETs and surveillance strategies according to recurrence risk stratification. From January 2000 to July 2011, 188 patients diagnosed with rectal NETs were included in this study. Patient characteristics, treatment methods, recurrence rates, risk factors of recurrence, and surveillance schedules were analyzed. The male-to-female ratio was 1.29:1 and the mean age at diagnosis was 50.6 years. The mean tumor size was 6.5 (range 1-30) mm. A total of 144 patients (76.6 %) were treated with endoscopic resection, and 44 patients (23.4 %) were treated with surgical resection as the initial treatment. During the follow-up period, ten patients (5.3 %) had disease recurrence, including one case of local recurrence and nine cases of recurrence at a distant site. Tumor size of >10 mm, invasion of the muscularis propria, increased mitotic index, lymphovascular invasion, and regional lymph node metastases were statistically significant predictors of recurrence by univariate analysis. Among the 152 patients without risk factors of recurrence, only one patient who underwent transanal resection had a local recurrence at 15 months after surgery. Our patients with rectal NETs showed favorable clinical outcomes and had a low rate of recurrence. Intensive surveillance with endoscopy or imaging study may not be required in patients without risk factors for recurrence.

Clinical outcomes of rectal neuroendocrine tumors ≤ 10 mm following endoscopic resection

This study was conducted to determine the clinical outcome of rectal neuroendocrine tumors (NETs)≤ 10 mm following conventional endoscopic resection. A total of 107 patients who underwent conventional endoscopic treatment for rectal NETs (median size 5.0 mm [range 1.0-10.0]) were followed up for a median of 31 months (range 13-121). The following data were analyzed: lesion characteristics, clinical outcomes, and histological features determined using tissue microarray analysis (TMA), including the mitotic count and the Ki-67 index. En bloc removal was achieved for all tumors, and the complete resection rate was 49.5% (53/107). Resection margin status was indeterminate in 37 patients (34.6%) and positive in 17 (15.9%). Rectal NETs in 71 patients demonstrated a score of ≤2 % on the Ki-67 index and<2 for mitotic count on TMA. In another 28 tumors that did not undergo TMA, the mitotic count was 0-1 per 10 high-power fields. Neither recurrence nor metastasis was noted during the follow-up period following resection. Rectal NETs (≤10 mm in size) appear to demonstrate benign behavior based on the mitotic count and the Ki-67 index. These results suggest that the outcome of rectal NETs (≤10 mm in size) following conventional endoscopic resection might be comparatively excellent, regardless of the resection margin status. However, long term follow-up data are required to confirm this.

The Epidemiology of Neuroendocrine Tumors in Taiwan: A Nation-Wide Cancer Registry-Based Study

BackgroundThe epidemiology of neuroendocrine tumors (NETs) is not well illustrated, particularly for Asian countries.MethodsThe age-standardized incidence rates and observed survival rates of NETs diagnosed in Taiwan from January 1, 1996 to December 31, 2008 were calculated using data of the Taiwan Cancer Registry (TCR) and compared to those of the Norwegian Registry of Cancer (NRC) and the US Surveillance, Epidemiology, and End Results (SEER) program.ResultsDuring the study period, a total of 2,187 NET cases were diagnosed in Taiwan, with 62% males and a mean age of 57.9 years-old. The age-standardized incidence rate of NETs increased from 0.30 per 100,000 in 1996 to 1.51 per 100,000 in 2008. The most common primary sites were rectum (25.4%), lung and bronchus (20%) and stomach (7.4%). The 5-year observed survival was 50.4% for all NETs (43.4% for men and 61.8% for women, P<0.0001). The best 5-year observed survivals for NETs by sites were rectum (80.9%), appendix (75.7%), and breast (64.8%).ConclusionsCompared to the data of Norway and the US, the age-standardized incidence rate of NETs in Taiwan is lower and the major primary sites are different, whereas the long-term outcome is similar. More studies on the pathogenesis of NETs are warranted to devise preventive strategies and improve treatment outcomes for NETs.