Incidence and survival of patients with small intestinal neuroendocrine tumours in a Danish NET center

The role of N-terminal pro-brain natriuretic peptide, chromogranin A, and 5-hydroxyindoleacetic acid in screening for carcinoid heart disease

Carcinoid heart disease (CHD) is a serious complication for patients with neuroendocrine tumors (NETs), and early detection is crucial. We aimed to investigate N-terminal pro-brain natriuretic peptide (NT-proBNP), chromogranin A (CgA), and plasma 5-hydroxyindoleacetic acid (P-5-HIAA) as a screening tool for detection of CHD. We prospectively included patients with disseminated small intestinal NETs (SI-NETs) and performed transthoracic echocardiography (TTE), questionnaires, and biochemical assessment of NT-proBNP, CgA, and P-5-HIAA. The presence and severity of CHD was assessed using a scoring system based on echocardiographic characteristics. A total of 93 patients were included in the final analysis. Fifteen (16%) were diagnosed with CHD. The median NT-proBNP (219 ng/L vs. 124 ng/L, p = .05), CgA (3930 pmol/L vs. 256 pmoL/L, p < .0001), and P-5-HIAA (1160 nmol/L vs. 210 nmoL/L, p < .0001) were significantly higher in patients with CHD compared to non-CHD patients. For NT-proBNP, the area under the receiver operating characteristic (AUROC) curve for detection of CHD was 0.67 (95% CI: 0.50-0.84), and at a 260 ng/L cutoff level, the sensitivity and specificity were 46% and 79%. For CgA, the AUROC was 0.91 (95% CI: 0.84-0.97), and at a cutoff level of 598 pmol/L, the sensitivity and specificity were 100% and 69%. For P-5-HIAA, the AUROC was 0.89 (95% CI: 0.80-0.98), and at a cutoff level of 752 nmol/L, the sensitivity and specificity were 92% and 85%. In conclusion, CgA and P-5-HIAA proved excellent markers of CHD while NT-proBNP lacked the required diagnostic accuracy to be used as a screening tool.

Understanding the increasing incidence of neuroendocrine tumors

INTRODUCTION

Neuroendocrine tumors (NETs) are a diverse group of tumors with origins from different primary sites such as gastro-entero-pancreatic, lung and endocrine tissue. Worldwide, their incidence has increased in recent decades. Advances in imaging and better clinical awareness are traditionally attributed to this trend; however, other factors such as genetic and environmental contributors are appreciated as well.

AREAS COVERED

The purpose of this article is to review the worldwide epidemiologic trends in incidence of NET through the decades and discuss the various factors potentially contributing to the observed changes in incidence trends.

EXPERT OPINION

Overall, the incidence of NET has increased across the globe over the last few decades. Although multiple genetics and environmental factors have been proposed, the majority of this increase in incidence is secondary to earlier detection. Future studies will help in more accurate assessments and an improved understanding of disease incidence among patients with different grades and differentiation.

The assessment of Ki-67 as a prognostic marker in neuroendocrine tumours: a systematic review and meta-analysis

Introduction

Gastroenteropancreatic neuroendocrine tumours (GEP NETs) are classified according to tumour mitotic count or Ki-67 labelling index (LI).

Aim(s)

To systematically review articles reporting the prognosis of patients by Ki-67 LI and thereby improve the ability of clinicians to prognosticate for their patients.

Method

265 abstracts were identified relating Ki-67 and survival. After exclusion criteria were applied, 22 articles remained. Articles were excluded if they described non-human specimens, were non-English language, published prior to 2000, reported non-GEP NETs, reported subgroups selected by treatment modality or included <20 cases. Random-effects meta-analysis was used to combine studies to estimate survival proportions.

Results

Authors used varied methods in which to present 5-year survival, with often limited survival information. This reduced the number of studies that could be included in the meta-analysis. 5-year survival for patients with grade 1 and 2 GEP NETs were estimated to be 89% (95% CI 85% to 92%, m=12 studies, n=977 participants) and 70% (95% CI 62% to 79%, m=9, n=726), respectively. Using an alternative grade 1/2 boundary of 5%, 5-year survival rates for Ki-67≤5% and 5–20% were estimated as 89% (95% CI 84% to 94%, m=7, n=654) and 51% (95% CI 44% to 59%, m=4, n=183), respectively. For Ki-67>20%, 5-year survival was estimated to be 25% (95% CI 12% to 38%, m=10, n=208).

Conclusions

Standardisation of grade boundaries has allowed us to combine data from multiple studies and amass a body of evidence linking Ki-67 and survival.