Neuroendocrine tumor G3: a pancreatic well-differentiated neuroendocrine tumor with a high proliferative rate

Effectiveness of Etoposide and Cisplatin vs Irinotecan and Cisplatin Therapy for Patients With Advanced Neuroendocrine Carcinoma of the Digestive System: The TOPIC-NEC Phase 3 Randomized Clinical Trial

Question

For patients with advanced neuroendocrine carcinoma of the digestive system, which of the 2 community standard regimens is more effective: etoposide plus cisplatin (EP) or irinotecan plus cisplatin (IP)?

Findings

In this randomized clinical trial of 170 patients who were chemotherapy naive and had recurrent or unresectable neuroendocrine carcinoma of the digestive system, median overall survival was 12.5 months in the EP arm and 10.9 months in the IP arm.

Meaning

Both EP and IP therapy remain standard first-line chemotherapy options.

Importance

Etoposide plus cisplatin (EP) and irinotecan plus cisplatin (IP) are commonly used as community standard regimens for advanced neuroendocrine carcinoma (NEC).

Objective

To identify whether EP or IP is a more effective regimen in terms of overall survival (OS) in patients with advanced NEC of the digestive system.

Design, Setting, and Participants

This open-label phase 3 randomized clinical trial enrolled chemotherapy-naive patients aged 20 to 75 years who had recurrent or unresectable NEC (according to the 2010 World Health Organization classification system) arising from the gastrointestinal tract, hepatobiliary system, or pancreas. Participants were enrolled across 50 institutions in Japan between August 8, 2014, and March 6, 2020.

Interventions

In the EP arm, etoposide (100 mg/m²/d on days 1, 2, and 3) and cisplatin (80 mg/m²/d on day 1) were administered every 3 weeks. In the IP arm, irinotecan (60 mg/m²/d on days 1, 8, and 15) and cisplatin (60 mg/m²/d on day 1) were administered every 4 weeks.

Main Outcomes and Measures

The primary end point was OS. In total, data from 170 patients were analyzed to detect a hazard ratio (HR) of 0.67 (median OS of 8 and 12 months in inferior and superior arms, respectively) with a 2-sided α of 10% and power of 80%. The pathologic findings were centrally reviewed following treatment initiation.

Results

Among the 170 patients included (median [range] age, 64 [29-75] years; 117 [68.8%] male), median OS was 12.5 months in the EP arm and 10.9 months in the IP arm (HR, 1.04; 90% CI, 0.79-1.37; P = .80). The median progression-free survival was 5.6 (95% CI, 4.1-6.9) months in the EP arm and 5.1 (95% CI, 3.3-5.7) months in the IP arm (HR, 1.06; 95% CI, 0.78-1.45). A subgroup analysis of OS demonstrated that EP produced more favorable OS in patients with poorly differentiated NEC of pancreatic origin (HR, 4.10; 95% CI, 1.26-13.31). The common grade 3 and 4 adverse events in the EP vs IP arms were neutropenia (75 of 82 [91.5%] patients vs 44 of 82 [53.7%] patients), leukocytopenia (50 of 82 [61.0%] patients vs 25 of 82 [30.5%] patients), and febrile neutropenia (FN) (22 of 82 [26.8%] patients vs 10 of 82 [12.2%] patients). While incidence of FN was initially high in the EP arm, primary prophylactic use of granulocyte colony-stimulating factor effectively reduced the incidence of FN.

Conclusions and Relevance

Results of this randomized clinical trial demonstrate that both EP and IP remain the standard first-line chemotherapy options. Although AEs were generally manageable, grade 3 and 4 AEs were more common in the EP arm.

Trial Registration

Japan Registry of Clinical Trials: jRCTs031180005; UMIN Clinical Trials Registry: UMIN000014795

Management of Well-Differentiated High-Grade (G3) Neuroendocrine Tumors

OPINION STATEMENT

In 2017, the World Health Organization (WHO) classification for pancreatic NET was updated to include a new category of well-differentiated high-grade (Ki 67 > 20%) pancreatic tumors (NET G3), distinct from high-grade poorly differentiated neuroendocrine carcinoma (NEC). NET G3 are considered a molecularly, radiologically, and prognostically distinct entity compared to NEC and NET G1/G2. The optimal first-line management in NET G3 and sequencing therapies remains a challenge awaiting future trials taking into consideration the unique characteristics of this category. In this review, we aim to summarize the current evidence in the management of NET G3.

Analysis of B-ultrasound and contrast-enhanced ultrasound characteristics of different hepatic neuroendocrine neoplasm

BACKGROUND

Hepatic neuroendocrine neoplasm (hNEN) is a highly heterogeneous tumor. The exact identification of the source and malignant degree of hNEN is important. However, there is a lack of information regarding diagnosis of hNEN with imaging. In addition, no studies have compared the imaging between hNEN and hepatocellular carcinoma (HCC) and among different sources and malignant degrees of hNEN.

AIM

To compare the ultrasound characteristics between hNEN and HCC and among different sources and malignant degrees of hNEN.

METHODS

A total of 55 patients with hNEN were recruited and defined as the hNEN group. Among them, 35 cases of hNET were defined as the hNET group. Twenty cases of hepatic neuroendocrine carcinoma (hNEC) were defined as the hNEC group. Among the 55 lesions, 29 were transferred from the pancreas, 20 were from the gastrointestinal tract, and six were from other sites. In total, 55 patients with HCC were recruited and defined as the HCC group. The characteristic differences of B-mode ultrasound and contrast-enhanced ultrasound (CEUS) between hNEN and HCC and among different sources and malignant degrees of hNEN were compared.

RESULTS

In the hNEN group, the proportions of multiple liver lesions, unclear borders, and high echo lesions were higher than those in the HCC group. The proportions of non-uniform echo and peripheral acoustic halo were lower than those in the HCC group (P < 0.05). The washout to iso-enhancement time and washout to hypo-enhancement time were lower than those in the HCC group (P < 0.05). The characteristics of B-ultrasound and CEUS among different sources of hNEN were similar, and the differences were not statistically significant (P > 0.05). B-mode ultrasound characteristics of hNET and hNEC were similar. The proportions of low enhancement at portal venous phase, non-uniform enhancement forms, and combined tumor vasculature in the hNEC group were larger than those in the hNEN group (P < 0.05).

CONCLUSION

Compared with HCC, hNEN showed multiple intrahepatic lesions, uniform high echo, uniform high enhancement at arterial phase, and rapid washout. Low enhancement at portal venous phase, overall non-uniform enhancement form, and the proportion of combined tumor vasculature in hNEC were larger than those in hNET.

Everolimus in the treatment of neuroendocrine tumors: efficacy, side-effects, resistance, and factors affecting its place in the treatment sequence

Since the initial approval of everolimus in 2011, there have been a number of important changes in therapeutic/diagnostic modalities as well as classification/staging systems of neuroendocrine tumors (NETs), which can significantly impact the use of everolimus in patients with advanced NETs. Areas covered: The efficacy of everolimus monotherapy and combination therapy demonstrated in clinical studies involving patients with advanced NETs are reviewed. Several factors affecting everolimus use are described including: the development and routine use of NET classification/staging systems; widespread use of molecular imaging modalities; side effects; drug resistance; and the availability of other treatment options. Furthermore, the current position of everolimus in the treatment approach is discussed, taking into account the recommendations from the recent guidelines. Expert opinion: Although everolimus demonstrated its high efficacy and tolerability in the RADIANT trials and other clinical studies, there still remain a number of controversies related to everolimus treatment in the management of NETs. The synergistic anti-growth effect of other agents in combination with everolimus or its effect on overall survival have not been established. The appropriate order of the use of everolimus in the treatment of advanced NETs still remains unclear, which needs to be defined in further studies and will be addressed in the new guidelines.

Recurrence of Pancreatic Neuroendocrine Tumors and Survival Predicted by Ki67

Background

Despite evidence of different malignant potentials, postoperative follow-up assessment is similar for G1 and G2 pancreatic neuroendocrine tumors (panNETs) and adjuvant treatment currently is not indicated. This study investigated the role of Ki67 with regard to recurrence and survival after curative resection of panNET.

Methods

Patients with resected non-functioning panNET diagnosed between 1992 and 2016 from three institutions were retrospectively analyzed. Patients who had G1 or G2 tumor without distant metastases or hereditary syndromes were included in the study. The patients were re-categorized into Ki67 0–5 and Ki67 6–20%. Cox regression analysis with log-rank testing for recurrence and survival was performed.

Results

The study enrolled 241 patients (86%) with Ki67 0–5% and 39 patients (14%) with Ki67 6–20%. Recurrence was seen in 34 patients (14%) with Ki67 0–5% after a median period of 34 months and in 16 patients (41%) with Ki67 6–20% after a median period of 16 months (p < 0.001). The 5-year recurrence-free and 10-year disease-specific survival periods were respectively 90 and 91% for Ki67 0–5% and respectively 55 and 26% for Ki67 6–20% (p < 0.001). The overall survival period after recurrence was 44.9 months, which was comparable between the two groups (p = 0.283). In addition to a Ki67 rate higher than 5%, tumor larger than 4 cm and lymph node metastases were independently associated with recurrence.

Conclusions

Patients at high risk for recurrence after curative resection of G1 or G2 panNET can be identified by a Ki67 rate higher than 5%. These patients should be more closely monitored postoperatively to detect recurrence early and might benefit from adjuvant treatment. A clear postoperative follow-up regimen is proposed.

Rb Loss and KRAS Mutation Are Predictors of the Response to Platinum-Based Chemotherapy in Pancreatic Neuroendocrine Neoplasm with Grade 3: A Japanese Multicenter Pancreatic NEN-G3 Study

Purpose: Patients with pancreatic neuroendocrine neoplasm grade-3 (PanNEN-G3) show variable responses to platinum-based chemotherapy. Recent studies indicated that PanNEN-G3 includes well-differentiated neuroendocrine tumor with G3 (NET-G3). Here, we examined the clinicopathologic and molecular features of PanNEN-G3 and assessed the responsiveness to chemotherapy and survival.Experimental Design: A total of 100 patients with PanNEN-G3 were collected from 31 institutions, and after central review characteristics of each histologic subtype [NET-G3 vs. pancreatic neuroendocrine carcinoma (NEC-G3)] were analyzed, including clinical, radiological, and molecular features. Factors that correlate with response to chemotherapy and survival were assessed.Results: Seventy patients analyzed included 21 NETs-G3 (30%) and 49 NECs-G3 (70%). NET-G3 showed lower Ki67-labeling index (LI; median 28.5%), no abnormal Rb expression (0%), and no mutated KRAS (0%), whereas NEC-G3 showed higher Ki67-LI (median 80.0%), Rb loss (54.5%), and KRAS mutations (48.7%). Chemotherapy response rate (RR), platinum-based chemotherapy RR, and prognosis differed significantly between NET-G3 and NEC-G3. Chemotherapeutic outcomes were worse in NET-G3 (P < 0.001). When we stratified PanNEN-G3 with Rb and KRAS, PanNENs-G3 with Rb loss and those with mutated KRAS showed significantly higher RRs to platinum-based chemotherapy than those without (Rb loss, 80% vs. normal Rb, 24%, P = 0.006; mutated KRAS, 77% versus wild type, 23%, P = 0.023). Rb was a predictive marker of response to platinum-based chemotherapy even in NEC-G3 (P = 0.035).Conclusions: NET-G3 and NEC-G3 showed distinct clinicopathologic characteristics. Notably, NET-G3 does not respond to platinum-based chemotherapy. Rb and KRAS are promising predictors of response to platinum-based chemotherapy for PanNEN-G3, and Rb for NEC-G3. Clin Cancer Res; 23(16); 4625-32. ©2017 AACR.

Everolimus in Pancreatic Neuroendocrine Carcinomas G3

OBJECTIVE

The aim of this study was to investigate everolimus efficacy in well-moderately differentiated pancreatic NEC (pNEC) G3.

METHODS

This was a retrospective analysis of patients with pNEC G3 and Ki67 20% to 55% treated with everolimus.

RESULTS

Fifteen patients with median Ki67 30% and Eastern Cooperative Oncology Group performance status 0 to 1 were evaluated. Of these, 4 patients received everolimus as first-line treatment, whereas 11 had been pretreated with chemotherapy or peptide receptor radionuclide therapy. Median progression-free survival was 6 months, and median overall survival was 28 months. Eleven patients achieved disease stabilization (DS) at 3 month follow-up. Six patients (40%) maintained DS for at least 12 months. Three of 4 patients who received everolimus as first-line therapy had sustained DS (progression-free survival, 12, 17, and 22 months). The safety profile was consistent with that previously reported, with adverse events occurring in 9 patients (66.7%).

CONCLUSIONS

This study suggests that everolimus is active in pNEC G3 with well-moderately differentiated morphology and Ki67 less than 55%, in which more toxic systemic chemotherapy is, to date, the only available treatment.