Circulating non-coding RNA (ncRNA) molecules are being investigated as biomarkers of malignancy, prognosis and follow-up in several neoplasms, including endocrine tumours of the pituitary, parathyroid, pancreas and adrenal glands. Most of these tumours are classified as neuroendocrine neoplasms (comprised of neuroendocrine tumours and neuroendocrine carcinomas) and include tumours of variable aggressivity. We consider them together here in this Review owing to similarities in their clinical presentation, pathomechanism and genetic background. No preoperative biomarkers of malignancy are available for several forms of these endocrine tumours. Moreover, biomarkers are also needed for the follow-up of tumour progression (especially in hormonally inactive tumours), prognosis and treatment efficacy monitoring. Circulating blood-borne ncRNAs show promising utility as biomarkers. These ncRNAs, including microRNAs, long non-coding RNAs and circular RNAs, are involved in several aspects of gene expression regulation, and their stability and tissue-specific expression could make them ideal biomarkers. However, no circulating ncRNA biomarkers have yet been introduced into routine clinical practice, which is mostly owing to methodological and standardization problems. In this Review, following a brief synopsis of these endocrine tumours and the biology of ncRNAs, the major research findings, pathomechanisms and methodological questions are discussed along with an outlook for future studies.

循环非编码 RNA (ncRNA) 分子正在被研究作为多种肿瘤的恶性肿瘤、预后和随访的生物标志物，包括垂体、甲状旁腺、胰腺和肾上腺的内分泌肿瘤。这些肿瘤中的大多数被归类为神经内分泌肿瘤（包括神经内分泌肿瘤和神经内分泌癌）并且包括不同侵袭性的肿瘤。由于它们的临床表现、病理机制和遗传背景相似，我们在本综述中将它们放在一起考虑。对于这些内分泌肿瘤的几种形式，没有可用的术前恶性肿瘤生物标志物。此外，还需要生物标志物来跟踪肿瘤进展（尤其是激素不活跃的肿瘤）、预后和治疗效果监测。循环血源性 ncRNA 作为生物标志物显示出有前景的用途。这些ncRNA，包括microRNA、长链非编码RNA和环状RNA，参与基因表达调控的多个方面，它们的稳定性和组织特异性表达可以使它们成为理想的生物标志物。然而，目前还没有循环 ncRNA 生物标志物被引入常规临床实践，这主要是由于方法学和标准化问题。在这篇综述中，简要概述了这些内分泌肿瘤和 ncRNA 的生物学，讨论了主要的研究成果、病理机制和方法学问题，并对未来的研究进行了展望。