Access through your institution Buy or subscribe Oesophageal cancer is the eighth most common cancer type worldwide, and the sixth most common source of cancer mortality accounting for over

400,000 deaths and 456,000 new cases every year (2012 figures). The most frequent type of this cancer is oesophageal squamous cell carcinoma (ESCC) representing 50–60% of cases worldwide,

rising to ~90% of cases in countries of Asia. ESCC is an aggressive malignancy and because most patients present with advanced disease, it is typified by a poor prognostic outcome (overall

5-year survival of 10–20%). There is therefore great clinical interest in better and earlier diagnosis. Although endoscopy, the current diagnostic technique of choice for ESCC, can be

change in cancer management as drug response and disease progression can be followed on a regular basis allowing the fine-tuning of treatment regimens to match the patient experience, in

other words a personalised medical approach. Circulating microRNAs (miRNAs) are particularly attractive candidates as non-invasive biomarkers as tumour-associated miRNAs present in the blood

are present at much higher levels than their counterpart circulating DNA, and unlike other RNA species, miRNAs can resist the high levels of RNase that are present in biological fluids. The

publication of the manuscript ‘_Circulating microRNAs in plasma of patients with oesophageal squamous cell carcinoma_ (ESCC)’ by Komatsu et al. in this journal was the first description of

circulating miRNAs in the plasma of ESCC patients (https://www.nature.com/articles/bjc2011198). In their highly cited publication, the authors measured levels of _miR-21_, _miR-184, miR-221_

and _miR-375_ in plasma samples taken from ESCC patients and healthy donors. These miRNAs were chosen on the basis of previous studies that showed an importance in ESCC tumour tissue.

Interestingly, none of these of these miRNAs were found to be differentially expressed in a previous study that used NGS to identify miRNAs in sera from ESCC patients

(https://academic.oup.com/clinchem/article/56/12/1871/5622231). In this publication, Komatsu et al. observed significant up-regulation in the levels of _miR-21_ and _miR-_184, although the

latter was only detectable in half of cases, down regulation of _miR-375_ and no difference in levels of _miR-221_ between plasma from 20 ESCC patients and 10 healthy controls. They

validated the differential expression of _miR-21_ and _miR-375_ in an extended cohort of 50 ESCC patients and 20 healthy controls and found an association of _miR-21_ levels with the

presence of vascular invasion and disease recurrence. They also investigated whether differential expression of _miR-21_ and _miR-375_ in plasma was reflected in the tumour. Although they

observed higher levels of _miR-21_ and lower levels of _miR-375_ in primary ESCC tissue when compared to normal mucosa, they did not see any difference between cases that had high or low

expression of these miRNAs in plasma. Similar findings have since been observed in many other studies (in many different cancer types), presumably reflecting intratumoural heterogeneity

and/or non-passive release of miRNAs from tumour tissue into the circulation. The authors further demonstrated that plasma levels of _miR-21_ decreased significantly after surgery, although

there were no differences in levels of _miR-375_. Similarly changes in the levels of _miR-21_ in post-operative plasma samples have subsequently been reported in other cancer types including

gastric, breast and lung cancer. This is a preview of subscription content, access via your institution ACCESS OPTIONS Access through your institution Subscribe to this journal Receive 24

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INFORMATION AUTHORS AND AFFILIATIONS * Molecular Oncology Group, Biodonostia Research Institute, 20014, San Sebastian, Spain Charles H. Lawrie * IKERBASQUE, Basque Foundation for Science,

Bilbao, Spain Charles H. Lawrie * Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom Charles H. Lawrie * Sino-Swiss Institute of Advanced Technology (SSIAT),

Shanghai University, Shanghai, China Charles H. Lawrie Authors * Charles H. Lawrie View author publications You can also search for this author inPubMed Google Scholar CORRESPONDING AUTHOR

Correspondence to Charles H. Lawrie. ETHICS DECLARATIONS COMPETING INTERESTS The author declare no competing interests. ADDITIONAL INFORMATION PUBLISHER’S NOTE Springer Nature remains

neutral with regard to jurisdictional claims in published maps and institutional affiliations. RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Lawrie,

C.H. Progress in the blood-based diagnosis of oesophageal squamous cell carcinoma (ESCC) using microRNAs: Comment on Komatsu et al. (BJC (2011) 105, 104–111). _Br J Cancer_ 128, 446–447

(2023). https://doi.org/10.1038/s41416-022-02034-8 Download citation * Received: 23 September 2022 * Revised: 14 October 2022 * Accepted: 17 October 2022 * Published: 28 October 2022 * Issue

Date: 02 February 2023 * DOI: https://doi.org/10.1038/s41416-022-02034-8 SHARE THIS ARTICLE Anyone you share the following link with will be able to read this content: Get shareable link

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