European Neuroendocrine Tumor Society (ENETS) 2023 guidance paper for colorectal neuroendocrine tumours

Long-term experience with octreotide and lanreotide for the treatment of gastroenteropancreatic neuroendocrine tumors

INTRODUCTION

The somatostatin analogs (SSA) octreotide and lanreotide are a mainstay in the treatment of neuroendocrine tumors (NET). The two pivotal trials differed considerably in terms of patient characteristics and are not directly comparable. Further comparative data are lacking.

METHODS

This retrospective chart review study included patients with gastroenteropancreatic NET grade 1 or 2 who were treated with octreotide LAR or lanreotide autogel. The main aim was to compare the two SSA based on progression-free survival (PFS) and overall survival (OS) from treatment start.

RESULTS

In total, 129 patients were analyzed, 60% (n = 77) had a small intestinal NET and 31% (n = 40) a pancreatic NET. Histologically, 34% (n = 44) had NET G1, 55% (n = 71) a NET G2, and 11% (n = 14) a NET G1/G2 unclassified. Lanreotide was used in 90 patients (70%) and octreotide in 39 patients (30%). Overall, the median PFS was 32.2 months (95% CI 23.0-42.9 months). No PFS difference (p = 0.8) was observed between lanreotide (29.8 months, 95% CI 18.7-48.5 months) and octreotide (36.0 months, 95% CI 23.2-68.2 months). Median OS from treatment start was calculated at 93.5 months (95% CI 71.1-132.9 months). Again, the median OS following lanreotide (113.4 months, 95% CI 62.3-NA months) or after octreotide (90.3 months, 95% CI 71.1-NA months) did not differ significantly (p > 0.9).

CONCLUSIONS

Our long-term experience with octreotide and lanreotide in NET did not reveal differences in antitumor effectiveness. This is consistent with previous reports and might suggest that both SSA can be used interchangeably if needed.

The Safety and Efficacy of Peptide Receptor Radionuclide Therapy for Gastro-Entero-Pancreatic Neuroendocrine Tumors: A Single Center Experience

The aim of the present study was to evaluate the safety and efficacy of radionuclide therapy with [177Lu]Lu-DOTA-TATE according to our single center experience at the University of Naples Federico II. For the present analysis, we considered 21 patients with progressive, advanced, well-differentiated G1 and G2 in patients with gastro-entero-pancreatic (GEP) neuroendocrine tumors (NETs) treated with [177Lu]Lu-DOTA-TATE according to the decisions of a multidisciplinary team. All patients underwent four cycles of 7-8 GBq of [177Lu]Lu-DOTA-TATE every 8 weeks. A whole-body scan (WBS) was performed 4, 48, and 168 h after each treatment. The dosimetry towards the organ at risk and target lesions was calculated. For each patient, renal and bone marrow parameters were evaluated before, during, and 3 months after the end of the treatment. Follow-up data were obtained and RECIST criteria were considered as the endpoint. Among 21 patients enrolled (mean age 65 ± 9 years); 17 (81%) were men and the small intestine was the most frequent location of disease (n = 12). A mild albeit significant variation (p < 0.05) in both platelets and white blood cell counts among all time points was observed, despite it disappearing 3 months after the end of the therapy. According to the RECIST criteria, 11 (55%) patients had a partial response to therapy and 8 (40%) had stable disease. Only one (5%) patient had disease progression 4 months after treatment. Our data confirm that [177Lu]Lu-DOTA is safe and effective in controlling the burden disease of G1/G2 GEP-NETs patients.

Effective utilization of polypectomy in endoscopic salvage treatment of rectal neuroendocrine tumors: a retrospective cohort study

Purpose

Current guidelines recommend endoscopic resection for rectal neuroendocrine tumors (RNETs) under 10 mm. Incomplete resections necessitate salvage procedures, highlighting the need for complete R0 resection. This study evaluates the efficacy and safety of wide hot snare polypectomy (WHSP) compared to endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) for the salvage treatment of small RNETs.

Methods

This retrospective study was conducted at Korea University Guro Hospital from January 2018 to December 2022. It compared the outcomes of salvage resections for RNETs ≤10 mm using 2 approaches: ESD and EMR vs. WHSP. Demographics, tumor characteristics, and clinical outcomes were compared. Efficacy was evaluated by the histological complete resection rate and procedure time, while safety was assessed by the incidence of complications.

Results

Out of 135 patients undergoing salvage resection for RNET, 14 who underwent transanal excision were excluded. Of the remaining 121, 99 underwent EMR or ESD, and 22 underwent WHSP. Baseline characteristics were similar between the 2 groups. The WHSP group demonstrated a significantly higher R0 resection rate (72.7% vs. 49.5%, P = 0.010) and a shorter median procedure time (3.5 minutes vs. 8.3 minutes). No complications were reported in the WHSP group.

Conclusion

WHSP is a rapid, straightforward, safe, and effective approach for the salvage treatment of RNETs less than 10 mm in diameter, particularly in patients without additional risk factors.

Endoscopic therapy versus surgical resection for elderly patients with colorectal neuroendocrine tumors

BACKGROUND

Endoscopic therapy (ET) and surgical resection (SR) are common surgical methods for the treatment of colorectal neuroendocrine tumors (CRNETs). However, for elderly patients, it remains unclear which surgical method yields better long-term outcomes.

METHODS

Elderly patients ≥ 65 years with CRNETs diagnosed from 2000 to 2020 were identified from the Surveillance, Epidemiology, and End Results database. Propensity score matching (PSM) was used to minimize selection bias. The Kaplan-Meier method and Cox proportional hazards models were utilized to evaluate the effects of diverse demographic and clinical factors on overall survival (OS) and cancer-specific survival (CSS).

RESULTS

A total of 2214 patients were included in the study, with 1417 patients in the ET group and 797 patients in the SR group. After PSM, the ET group outperformed the SR group in terms of OS (hazard ratio [HR] 0.56, 95% confidence interval [CI] 0.44-0.70) and CSS (HR 0.21, 95% CI 0.11-0.40). Similarly, the ET group maintained its advantage in mean 1-, 3-, and 5-year OS and CSS rates compared to the SR group (P < 0.001). Multivariate Cox regression analysis identified age, sex, grade, marital status, and treatment modality as independent risk factors affecting OS, while age, sex, marital status, and treatment modality were identified as independent risk factors affecting CSS.

CONCLUSIONS

ET offered superior long-term outcomes for elderly patients ≥ 65 years with CRNETs.

Pathological Characteristics, Management, and Prognosis of Rectal Neuroendocrine Tumors: A Retrospective Study from a Tertiary Hospital

BACKGROUND

Rectal neuroendocrine tumors (rNENs) are rare, constituting 1-2% of rectal tumors, and are often asymptomatic, leading to challenges in early diagnosis. Current management guidelines recommend endoscopic resection for small lesions and surgical intervention for larger or high-risk tumors. This study aims to retrospectively analyze the pathological characteristics, management, and prognosis of rNEN patients.

METHODS

Data from the Neuroendocrine Tumor Registry at a tertiary hospital in Milan, Italy from 2005 to 2023 were retrospectively analyzed. Patient demographics, disease characteristics, pathology findings, treatment details, and surveillance data were collected. Statistical analyses included descriptive statistics, multivariable binary logistic regression, and Kaplan-Meier survival analysis.

RESULTS

Forty-five patients were included, 53.3% male with a mean age of 57.5 years. Most patients were asymptomatic, with incidental diagnosis during colonoscopy. Endoscopic excision was the primary treatment modality (77.8%), with surgical resection reserved for incomplete or inappropriate endoscopic resections. Disease progression occurred in 13 patients (28.9%), with tumor-related mortality of 22.2%. Kaplan-Meier analysis showed 5- and 10-year survival rates of 68.8% and 59.1%, respectively, with corresponding progression-free survival rates of 72.8% and 54.0%. Tumor stage was significantly associated with disease progression on multivariable analysis (OR = 7.230, p = 0.039).

CONCLUSIONS

This study highlights the heterogeneous presentation and prognosis of rNENs, with a substantial proportion diagnosed incidentally. Endoscopic management was predominantly utilized, aligning with current guidelines for localized tumors. Tumor stage emerged as a significant predictor of disease progression, emphasizing the importance of accurate staging for optimal management. Further research is warranted to refine management protocols and validate these findings.

Lateral pelvic lymph nodes dissection of rectal neuroendocrine neoplasms: A prospective case-series and literature review

BACKGROUND

Rectal neuroendocrine neoplasms are relatively rare. Patients with rectal neuroendocrine neoplasms undergoing radical surgery have a higher rate of lymph node metastases. Robust evidence on the status of lateral pelvic lymph node metastases and the role of lateral pelvic lymph node dissection in those patients is lacking. This case-series study aimed to explore and address these issues.

METHODS

This single-center, prospective case series consecutively enrolled patients with biopsy-proven rectal neuroendocrine neoplasms in a tertiary referral hospital between June 2022 and January 2024. All eligible patients underwent laparoscopic total mesorectal excision surgery and bilateral lateral pelvic lymph node dissection under general anesthesia. The clinicopathologic features, surgical outcomes, and postoperative complications were presented. The last follow-up was conducted in March 2024.

RESULTS

A total of 11 patients with rectal neuroendocrine neoplasms-3 female and 8 male-were enrolled. The average age was 60.0 years (range, 53.5-65.5 years), and the median tumor size was 2.0 cm (range, 1.6-2.5 cm). Tumors invaded the muscularis propria in 7 patients. There were 3 cases of neuroendocrine tumor G1, 6 cases of neuroendocrine tumor G2, and 2 cases of neuroendocrine carcinoma. Among these patients, 11 (100.0%) had lymph node metastases, and 6 (54.5%) had lateral pelvic lymph node metastases. In addition, in 2 patients, only lateral pelvic lymph node metastases were observed, without involvement of the mesenteric lymph nodes. Five patients had tumors located on the left wall of the rectum, and only left-sided lateral pelvic lymph node metastases were observed. The other patient had both sides of lateral pelvic lymph node metastases due to circumferential growth of the tumor around the rectum. Anal preservation was achieved in all patients. The median operating time was 235.0 minutes (range, 210.5-335.5 minutes), and the median estimated blood loss was 50.0 mL (range, 45.0-75.0 mL). Two patients experienced postoperative dysuria and recovered spontaneously within 2-4 months after surgery.

CONCLUSION

On the basis of a prospective case series, we demonstrate, for the first time, the lateral pelvic lymph node metastasis status in patients with rectal neuroendocrine neoplasms requiring radical total mesorectal excision surgery. Simultaneous bilateral lateral pelvic lymph node dissection may be a feasible and beneficial procedure for preventing local recurrence in these patients due to the lack of definitive neoadjuvant or adjuvant therapy options.

Distinct clinicopathological features of neuroendocrine liver metastases originating from the pancreas and rectum

INTRODUCTION

Survival comparisons among patients with liver metastases from pancreatic and rectal neuroendocrine tumors (NETs) were limited, and the efficacy of observation rules in patients undergoing hepatectomy for neuroendocrine liver metastases (NELMs) was unknown. This study aims to distinguish these characteristics and clarify the effects of the observation rules on NELMs.

METHODS

Clinical data were separately collected from patients with pancreatic and rectal NELMs at medical centers in both Japan and China. The Japanese cohort followed the observation rules for the resection of NELMs. A comparative analysis was conducted on clinical characteristics and prognosis features such as overall survival time (OS) and disease-free survival interval (DFS-I).

RESULTS

Enrollment included 47 and 34 patients from Japan and China, respectively. Of these, 69 and 12 patients had tumors originating from the pancreas and rectum, respectively. The OS time in patients undergoing primary tumor resection was significantly longer; however, the OS time between the patients undergoing and not undergoing radical resection of liver metastasis was the same. In asynchronous NELMs, patients with rectal (R)-NELMs showed a significantly higher proportion of type III NELMs. Additionally, the median DFS-I of asynchronous R-NELMs was longer than the recommended follow-up time, with 71.4% of them classified as G2. In the Japanese cohort, patients who adhered to the observation rules exhibited a longer median DFS after hepatectomy for NELMs compared with their counterparts.

CONCLUSION

Although curative surgery is crucial for primary lesions, personalized approaches are required to manage NELMs. Extended overall follow-ups and shortened follow-up intervals are recommended for G2 stage rectal NETs. The observation rules for NELMs require further validation with a larger sample size.

Endoscopic and Surgical Treatment of Gastrointestinal Neuroendocrine Neoplasms: A Population-based Comparative Study

BACKGROUND

Controversy surrounds the indications for endoscopic treatment (ET) versus surgery in addressing gastrointestinal neuroendocrine neoplasms (GI-NENs). This paper aims to compare the long-term survival prognosis between ET and surgery for patients with GI-NENs.

METHODS

A retrospective analysis of GI-NEN patients diagnosed between 2000 and 2020 was conducted using the SEER database. Overall survival (OS) and cancer-specific survival (CSS) were estimated using the Kaplan-Meier method. Prognostic factors were assessed through univariate and multivariate Cox regression analyses. Propensity score matching (PSM) was employed to adjust for clinical variables.

RESULTS

This study encompassed 12,016 patients with GI-NENs, with 3732 patients (31.1%) undergoing ET and 8284 patients (68.9%) opting for surgery. The rectum was the most frequent location for ET, while the small bowel was the predominant site for surgery. Both the ET and surgical groups exhibited similar overall survival risk and cancer-specific survival risk before and after matching. No significant differences in the 1-year, 3-year, 5-year, and 10-year OS and CSS rates were observed between the ET and surgery groups after PSM. Nevertheless, subgroup analysis revealed a significantly better CSS in the ET group than the surgery group, particularly in stage I and tumors sized <10mm ( P <0.01). In the colon subgroup, the OS and CSS of the ET group were superior to those of the surgery group ( P <0.05).

CONCLUSION

Endoscopic treatment and surgery demonstrate comparable long-term survival prognoses for treating GI-NENs. ET emerges as a viable option for patients averse to surgical interventions.

[Systemic treatment of patients with metastatic neuroendocrine Neoplasia]

Due to the complexity and heterogeneity of metastatic NEN an interdisciplinary expert team should be involved in an individualized treatment strategy. SSA is the mainstay of antisecretory treatment in most functioning tumors. In antiproliferative intention SSA are first line treatment in receptor positive low proliferative NET. In intestinal metastatic disease PRRT is best established second line treatment. Further options are Everolimus (labeled) and tyrosine kinase inhibitors (off-label). Everolimus is the only approved drug for antiproliferative treatment in patients with metastatic lung NET, whereas in pancreatic NET more therapeutic options are available (SSA, chemotherapy, PRRT, Sunitinib, Everolimus) without a standard of best sequence. In patients with metastatic NEC standard first line treatment (platinum + etoposide) has not changed for decades and new treatment options for this fatal disease are urgently needed. Benefit of immunotherapy is limited to a small subset of patients - new combinations are under investigation. This review summarizes the standard of care, criteria of treatment selection and new developments for systemic therapy in patients with metastatic NEN.

Association Between Female Sex and Better Survival in Gastroenteropancreatic Neuroendocrine Tumors

INTRODUCTION

Studies conflict on whether sex influences survival in gastroenteropancreatic neuroendocrine tumors (GEP-NETs). GEP-NETs express receptors and genes responsive to female hormones. We hypothesized that women would have improved survival and this difference would be greater in premenopausal age women compared to older women.

MATERIALS AND METHODS

The National Cancer Database from 2004 to 2016 was queried for patients with GEP-NETs based on histologic code. Demographic, tumor, treatment, and socioeconomic characteristics were compared between men and women and age ≤45 or >65 y using Fisher's exact and Wilcoxon tests as appropriate. The primary endpoint was overall survival (OS), assessed by Kaplan-Meier survival analysis.

RESULTS

Included in the study were 73,521 patients with small bowel neuroendocrine tumors (SBNETs), gastric neuroendocrine tumors (GNETs), or pancreas neuroendocrine tumors (36,197 female, 37,324 male). Women lived longer regardless of primary site, with the largest difference in GNETs (median OS 139 versus 85 mo) and smallest in SBNETs (121 versus 116, P < 0.001 for both). While male patients more often had high grade and metastatic disease, female sex remained independently associated with improved OS after adjusting for confounders (hazard ratio 0.84, P < 0.001). In GNETs and SBNETs, female sex had a larger beneficial effect on OS in premenopausal than postmenopausal patients.

CONCLUSIONS

Women with GEP-NETs have improved survival over men, especially in the premenopausal age group. This may be due to a protective effect of female hormones; however, further studies are necessary to uncover the biologic basis of this difference.

Outcome of Endoscopic Resection of Rectal Neuroendocrine Tumors ≤ 10 mm

BACKGROUND AND AIM

Guidelines suggest endoscopic resection for rectal neuroendocrine tumors (rNETs) < 10 mm, but the most appropriate resection technique is unclear. In real-life clinical practice, the endoscopic removal of unrecognized rNETs can take place with "simple" techniques and without preliminary staging. The aim of the current study is to report our own experience at a referral center for both neuroendocrine neoplasms and endoscopy.

METHODS

Retrospective analyses of polypectomies were performed at the Humanitas Research Hospital for rNETs (already diagnosed or previously unrecognized).

RESULTS

A total of 19 patients were included, with a median lesion size of 5 mm (range 3-10 mm). Only five lesions were suspected as NETs before removal and underwent endoscopic ultrasound (EUS) before resection, being removed with advanced endoscopic techniques. Unsuspected rNETs were removed by cold polypectomy in eleven cases, EMR in two, and biopsy forceps in one. When described, the margins were negative in four cases, positive in four (R1), and indeterminate in one. The median follow-up was 40 months. A 10 mm polypoid lesion removed with cold snare polypectomy (G2 R1) needed subsequent surgery. Eighteen patients underwent EUS after a median time of 6.5 months from resection. The EUS identified local recurrence after 14 months in a 7 mm polypoid lesion removed with cold snare polypectomy (G1 R1); the lesion was treated with cap-assisted EMR. For all the other lesions, the follow-up was negative.

CONCLUSIONS

When rNETs are improperly removed without prior staging, caution must be exercised. The data from our cohort suggest that even if inappropriate resection had happened, patients may be safely managed with early EUS evaluation.

Altered biodistribution of [68Ga]Ga-DOTA-TOC during somatostatin analogue treatment

PURPOSE

The need for an interval between the administration of long-acting Somatostatin Receptor Analogues (SSA) and the [68Ga]Ga-DOTA-TATE PET has been questioned based on recent literature in the new EANM guidelines. Here an earlier studies showed that SSA injection immediately before SSTR PET had minimal effect on normal organ and tumor uptake (1). However, data are scarce and there are (small) differences between [68Ga]Ga-DOTA-TATE and [68Ga]Ga-DOTA-TOC binding affinity, and it remains unknown whether these findings can be directly translated to scans with [68Ga]Ga-DOTA-TOC as well. The purpose of this study was to assess the effect of SSA use on the biodistribution in a subsequent [68Ga]Ga-DOTA-TOC PET/CT and compare this intra-individually across several cycles of SSA treatments.

METHODS

Retrospectively, 35 patients with NENs were included. [68Ga]Ga-DOTA-TOC PET at staging and after the 1st and 2nd cycle of SSA were included. SUVmean and SUVmax of blood, visceral organs, primary tumor and two metastases were determined. Also, the interval between SSA therapy and the PET scan was registered.

RESULTS

Treatment with SSA resulted in a significantly higher bloodpool activity and lower visceral tracer uptake. This effect was maintained after a 2nd cycle of SSA therapy. Furthermore, there was an inverse relationship between bloodpool tracer availability and visceral tracer binding and a positive correlation between bloodpool tracer availability and primary tumor tracer uptake. With an interval of up to 5 days, there was a significantly higher bloodpool activity than at longer intervals.

CONCLUSION

Absolute comparison of the SUV on [68Ga]Ga-DOTA-TOC PET should be done with caution as the altered biodistribution of the tracer after SSA treatment should be taken into account. We recommend not to perform a scan within the first 5 days after the injection of lanreotide.

[Current developments in the treatment of neuroendocrine tumors]

BACKGROUND

Well-differentiated neuroendocrine tumors (NET) are rare malignancies that are clinically very heterogeneous. Accordingly, their treatment is also complex and dependent on various factors. With currently available systemic therapies, the prognosis is often favorable.

OBJECTIVES

This article aims to provide an overview of current treatment strategies for NET, addressing the most important NET locations.

METHODS

The current European guidelines and further relevant literature on the treatment of NET were reviewed for this purpose.

RESULTS

The therapeutic spectrum for NET is extremely broad: For NET of the stomach/duodenum, appendix, and rectum, endoscopic or surgical resection is often sufficient, and metastatic tumors are rare. NET of the pancreas, small intestine and lung should also undergo potentially curative resection in the early stages. In the metastatic stage, locoregional treatments such as surgery and liver tumor embolization play a role. Major advances have been made in drug therapy, with somatostatin analogs (octreotide and lanreotide), an mTOR inhibitor (everolimus), and a tyrosine kinase inhibitor (sunitinib) being widely used. Peptide receptor radionuclide therapy (PRRT) is also an invaluable option. In some cases, classic chemotherapy is indicated.

CONCLUSIONS

Many effective therapies are now available for NET. It is important to select the right therapy at the right time for each patient through interdisciplinary management.

[Clinical significance of neuroendocrine tumors : Incidence, symptoms, diagnosis, stage, and prognostic factors and their influence on disease management]

BACKGROUND

Neuroendocrine neoplasms (NEN) are heterogenous with an increasing incidence in recent years.

OBJECTIVES

Overview on incidence, symptoms, diagnostics, grading, imaging and prognostic determinants, including factors having an impact on therapeutic management.

METHODS

Review on current literature, including original articles, reviews, guidelines and expert opinions.

RESULTS

NEN are mainly located in the gastrointestinal tract and their incidence has increased in recent years, mainly due to improved diagnostics, e.g., cross-sectional imaging. Clinical characteristics include hormone excess syndromes (carcinoid syndrome). Laboratory markers such as chromogranin A are commonly used as part of routine diagnostics, followed by endoscopic and endosonographic procedures, which also allow biopsies to be obtained. Tumor spread can be determined by contrast-enhanced computed tomography/magnetic resonance imaging (CT/MRI) or somatostatin receptor (SSRT)-PET/CT (positron emission tomography). Prognostic factors include Ki67 index, type, and grading. Resection with curative intent is the therapy of choice. In a metastasized setting, SSRT-directed treatment approaches are favored, while in dedifferentiated NEN, conventional chemotherapy is needed.

CONCLUSION

A broad diagnostic armamentarium can be offered to NEN patients and the improved diagnostic procedures have most likely caused a raising incidence in recent years. Among others, prognostic factors are Ki67 and NEN subtypes; these clinical determinants also have an impact on patient management.

[Endocrine oncology : An update on surgical treatments]

BACKGROUND

In the management of solid tumours, routine concepts are increasingly being transformed into individualized patient treatment. Endocrine surgery is traditionally characterized by resection strategies that are adapted to phenotype and genotype of the underlying disease. As complication rates in surgery correlate with the extent of resection, continuous efforts are made to identify selection criteria in order to limit the extent of surgery without compromising the oncological outcome. The aim is to design risk-stratified precision endocrine surgery.

MATERIALS AND METHODS

A search was carried out in PubMed for new and modern strategies and approaches for oncological endocrine surgery.

RESULTS

Several developments in surgical technique and technology, molecular pathology, medical therapy, and study data identify the potential to adapt the surgical strategy in all areas of endocrine surgery.

CONCLUSION

According to prevalent data, limited extent of resection in thyroid cancer surgery shows a reduction in complication rates while preserving oncological outcome when adequate selection criteria are implemented. New insights and innovative technologies also influence additional areas in oncological endocrine surgery for parathyroid, adrenal, and neuroendocrine neoplasia. However, the broad practice of these new concepts needs to be evaluated with regard to long-term oncological outcome.

Evaluation of a blood miRNA/mRNA signature to follow-up Lu-PRRT therapy for G1/G2 intestinal neuroendocrine tumors

Background

177Lu-oxodotreotide peptide receptor therapy (LuPRRT) is an efficient treatment for midgut neuroendocrine tumors (NETs) of variable radiological response. Several clinical, biological, and imaging parameters may be used to establish a relative disease prognosis but none is able to predict early efficacy or toxicities. We investigated expression levels for mRNA and miRNA involved in radiosensitivity and tumor progression searching for correlations related to patient outcome during LuPRRT therapy.

Methods

Thirty-five patients received LuPRRT for G1/G2 midgut NETs between May 2019 and September 2021. Peripheral blood samples were collected prior to irradiation, before and 48 h after the second and the fourth LuPRRT, and at 6-month follow-up. Multiple regression analyses and Pearson correlations were performed to identify the miRNA/mRNA signature that will best predict response to LuPRRT.

Results

Focusing on four mRNAs and three miRNAs, we identified a miRNA/mRNA signature enabling the early identification of responders to LuPRRT with significant reduced miRNA/mRNA expression after the first LuPRRT administration for patients with progressive disease at 1 year (p < 0.001). The relevance of this signature was reinforced by studying its evolution up to 6 months post-LuPRRT. Moreover, nadir absolute lymphocyte count within the first 2 months after the first LuPRRT administration was significantly related to low miRNA/mRNA expression level (p < 0.05) for patients with progressive disease.

Conclusion

We present a pilot study exploring a miRNA/mRNA signature that correlates with early hematologic toxicity and therapeutic response 12 months following LuPRRT. This signature will be tested prospectively in a larger series of patients.

Management & surveillance of rectal neuroendocrine tumours: a single-centre retrospective analysis

BACKGROUND

Rectal neuroendocrine tumours (rNETs) are rare but are increasing in incidence. Current management and surveillance recommendations are based on low-grade evidence. Follow-up practices are often inconsistent and costly. This retrospective study analyses a single-centre's experience with rNETs to assess incidence, management practices, outcomes, and guideline adherence.

METHODS

This is a single-centre retrospective study from Queensland Australia, spanning from 2012 to 2023. Twenty-eight rNET cases met inclusion criteria. Examined parameters included incidence, management, outcomes and adherence to European Neuroendocrine Tumour Society (ENETS) guidelines. R1 resection rate was analysed for associations with resection technique and lesion recognition and recurrence rate was assessed in all patients.

RESULTS

This study shows an increasing incidence of rNETs during the study period, reflecting a global trend. R1 resection rate at initial endoscopy was 75%. There was a general lack of advanced endoscopic techniques utilized and poor lesion recognition, however a statistically significant correlation was not established between these factors and an R1 result (P < 0.05). Most patients with an R1 result had subsequent re-resection to render the result R0, however five patients (33%) underwent surveillance with no reports of recurrence on follow-up. Overall, follow-up practices in our cohort were inconsistent and did not adhere to guidelines.

CONCLUSION

rNETs are increasing in incidence, emphasizing the need for standardized management and surveillance. Further training is required for rNET recognition and advanced endoscopic resection techniques. Further research is required to assess long-term outcomes in surveilled R1 cases, understand optimal endoscopic resection techniques and further develop local surveillance guidelines.

Endoscopic submucosal dissection for rectal neuroendocrine tumours: A multicentric retrospective study

INTRODUCTION

Endoscopic Submucosal Dissection (ESD) has been reported as a feasible and effective treatment for Rectal Neuroendocrine Tumours (R-NETs). However, most of the experience on the topic comes from retrospective tertiary centre from Eastern Asia. Data on ESD for R-NETs in Western centres are lacking.

MATERIALS AND METHODS

This is a retrospective study, including patients who underwent endoscopic resection of R-NETS by ESD between 2015 and 2020 in Western Centres. Important clinical variables such as demographic, size of R-NETs, histological type, presence of lymphovascular invasion or distant metastasis, completeness of the endoscopic resection, recurrence, and procedure related complications were recorded.

RESULTS

40 ESD procedure on R-NETs from 39 patients from 8 centres were included. Mean R-NETs size was 10.3 mm (SD 4.01). Endoscopic en-bloc resection was achieved in 39/40 ESD (97.5 %), R0 margin resection was obtained in 87.5 % (35/40) of the procedures, one patient was referred to surgery for lymphovascular invasion, two procedures (5 %) reported significant episodes of bleeding, whereas a perforation occurred in one case (1/40, 2.5 %) managed endoscopically. Recurrence occurred in 1 patient (2.5 %).

CONCLUSION

ESD is an effective and safe treatment for R-NETs in western centres.

Advances in Radionuclide Therapies for Patients with Neuro-endocrine Tumors

PURPOSE OF REVIEW

To provide insights into the role of peptide receptor radionuclide therapy (PRRT) in patients with advanced neuroendocrine tumors (NET) and an overview of possible strategies to combine PRRT with locoregional and systemic anticancer treatments.

RECENT FINDINGS

Research on combining PRRT with other treatments encompasses a wide variety or treatments, both local (transarterial radioembolization) and systemic therapies, chemotherapy (i.e., capecitabine and temozolomide), targeted therapies (i.e., olaparib, everolimus, and sunitinib), and immunotherapies (e.g., nivolumab and pembrolizumab). Furthermore, PRRT shows promising first results as a treatment prior to surgery. There is great demand to enhance the efficacy of PRRT through combination with other anticancer treatments. While research in this area is currently limited, the field is rapidly evolving with numerous ongoing clinical trials aiming to address this need and explore novel therapeutic combinations.

Clinical Outcome of Patients with Gastric, Duodenal, or Rectal Neuroendocrine Tumors after Incomplete Endoscopic Resection

Objectives: Our aim was to investigate the clinical outcome of patients with well-differentiated gastric, duodenal, and rectal neuroendocrine tumors after treatment with incomplete endoscopic resection due to the finding of microscopic positive resection margins (R1). Methods: This is a retrospective analysis of consecutive patients with type 1 gastric, non-ampullary non-functioning duodenal, or rectal neuroendocrine neoplasms with positive R1 margins after endoscopic resection. The rate of tumor recurrence and progression-free survival were considered to be the study's main endpoints. Statistical analysis was performed using MedCalc® v.17 software and a p-value of <0.05 was considered significant. A Cox proportional-hazard regression was performed to identify risk factors for disease recurrence/progression. Results: After evaluating 110 patients, a total of 58 patients were included in the final analysis (15 gastric NENs, 12 duodenal NENs, and 31 rectal NENs). After evidence of endoscopic R1 resection had been gathered, 26 patients (44.8%) underwent an endoscopic/surgical extension of the previous resection. Tumor progression (all local recurrences) occurred in five out of fifty-eight patients (8.6%) with a median PFS of 36 months. There were no tumor-related deaths. G2 grading and the gastric primary tumor site were the only features significantly associated with the risk of recurrence of the disease (HR: 11.97 [95% CI: 1.22-116.99], HR: 12.54 [95% CI: 1.28-122.24], respectively). Conclusions: Tumor progression rarely occurs in patients with microscopic positive margin excision (R1) after endoscopic resection and does not seem to affect patients' clinical outcomes.

Sequencing Treatments in Patients with Advanced Well-Differentiated Pancreatic Neuroendocrine Tumor (pNET): Results from a Large Multicenter Italian Cohort

Background: The optimal treatment sequencing for advanced, well-differentiated pancreatic neuroendocrine tumors (pNETs) is unknown. We performed a multicenter, retrospective study to evaluate the best treatment sequence in terms of progression-free survival to first-line (PFS1) and to second-line (PFS2), and overall survival among patients with advanced, well-differentiated pNETs. Methods: This multicenter study retrospectively analyzed the prospectively collected data of patients with sporadic well-differentiated pNETs who received at least two consecutive therapeutic lines, with evidence of radiological disease progression before change of treatment lines. Results: Among 201 patients, 40 (19.9%) had a grade 1 and 149 (74.1%) a grade 2 pNET. Primary tumor resection was performed in 98 patients (48.8%). First-line therapy was performed in 128 patients with somatostatin analogs (SSA), 35 received SSA + radioligand therapy (RLT), 21 temozolomide-based chemotherapy, and 17 SSA + targeted therapy. PFS was significantly longer in patients with grade 1 pNETs compared to those with grade 2, in patients who received primary tumor surgery, and in patients treated with RLT compared to other treatments. At multivariate analysis, the use of upfront RLT was independently associated with improved PFS compared to SSA. Second-line therapy was performed in 94 patients with SSA + targeted therapy, 35 received chemotherapy, 45 SSA + RLT, and 27 nonconventional-dose SSA or SSA switch. PFS was significantly longer in patients treated with RLT compared to other treatments. At multivariate analysis, the type of second-line therapy was independently associated with the risk for progression. OS was significantly longer in patients who received primary tumor surgery, with Ki67 < 10%, without extrahepatic disease, and in patients who received SSA-RLT sequence compared to other sequences. Conclusions: In this large, multicenter study, RLT was associated with better PFS compared to other treatments, and the SSA-RLT sequence was associated with the best survival outcomes in patients with pNETs with Ki67 < 10%. Primary tumor surgery was also associated with improved survival.

Endoscopic management of gastric, duodenal and rectal NETs: Position paper from the Italian Association for Neuroendocrine Tumors (Itanet), Italian Society of Gastroenterology (SIGE), Italian Society of Digestive Endoscopy (SIED)

The present paper reflects the position of the Italian Association for Neuroendocrine Tumors (Itanet), the Italian Society of Gastroenterology (SIGE), and the Italian Society of Digestive Endoscopy (SIED) regarding the management of patients affected by gastric, duodenal, and rectal neuroendocrine neoplasms (NENs) amenable to endoscopic treatment. The key questions discussed in this paper are summarized in Table 1. Data were extracted from the MEDLINE database through searches; expert opinions and recommendations are provided in accordance with the available scientific evidence and the authors' expertise. Recommendations are presented alongside a level of evidence and grade of recommendation based on the GRADE system. This paper specifically focuses on subgroups of NENs considered suitable for endoscopic management according to current international guidelines: i. well-differentiated gastric neuroendocrine tumors (gNET) type 1 < 2 cm and selected cases of type 3; ii. well-differentiated duodenal, non-functioning, non-ampullary NET with size < 2 cm; and well-differentiated rectal NET with size < 2 cm.

Comparing surgical and endoscopic resection approaches for colorectal neuroendocrine tumors within the diameter range of 10-20mm: an inverse probability weighting analysis based on the SEER database

Background

Currently, the primary treatment modalities for colorectal neuroendocrine tumors (CRNET) with a diameter between 10mm and 20mm are surgical resection (SR) and endoscopic resection (ER). However, it remains unclear which surgical approach yields the greatest survival benefit for patients.

Methods

This study included data from patients diagnosed with CRNET with tumor diameters ranging from 10mm to 20mm between the years 2004 and 2019, obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Patients were categorized into ER and SR groups based on the respective surgical approaches. Inverse probability weighting (IPTW) was employed to mitigate selection bias. Kaplan-Meier analysis and log-rank tests were utilized to estimate overall survival (OS) and cancer-specific survival (CSS). Cox regression analysis (univariate and multivariate) was performed to evaluate potential factors influencing survival.

Results

A total of 292 CRNET patients were included in this study (ER group: 108 individuals, SR group: 184 individuals). Prior to IPTW adjustment, Kaplan-Meier analysis and Cox proportional hazard regression analysis demonstrated that the OS and CSS of the SR group were inferior to those of the ER group. However, after IPTW adjustment, no statistically significant differences in prognosis were observed between the two groups. Subgroup analyses revealed that patients with muscular invasion, positive lymph nodes, or distant metastasis derived greater survival benefits from SR. Significant differences in OS and CSS between the two groups were also observed across different age groups.

Conclusion

For patients with mucosal-limited lesions and without local lymph node or distant metastasis, ER is the preferred surgical approach. However, for patients with muscular invasion or positive lymph nodes/distant metastasis, SR offers a better prognosis. The choice of surgical approach should be based on the specific clinical characteristics of patients within different subgroups.

ASO Practice Guidelines Series: Surgical Management of Gastrointestinal (Midgut) Neuroendocrine Neoplasms

Gastrointestinal midgut neuroendocrine neoplasms (NENs) are a heterogeneous group of uncommon malignancies. For well-differentiated NENs, known as neuroendocrine tumors (NETs), surgery is a cornerstone of management in localized and metastatic disease. Because of heterogeneous tumor behaviour, association with endocrine syndrome, and prognosis, the management of NETs must be individualized to all these factors in addition to the primary site. With the fast pace of advancement in the field, both for therapies and understanding of tumoral etiology and behaviour, it is important for surgical oncologists to remain updated on guidelines recommendations and suggested treatment pathways. Those guidelines provide important guidance for management of NETs but are largely based on expert opinions and interpretation of retrospective evidence. This article reviews highlights of most recent practice guidelines for midgut (gastric, duodenal, small intestinal, and appendiceal) NETs.