Evaluation of Roles of MicroRNA-21 and MicroRNA-18a in Esophageal Squamous Cell Carcinoma and Comparison of Their Changes in Expression Post-Chemoradiotherapy

A systematic review of circulating predictive and prognostic biomarkers to aid the personalised use of radiotherapy in the radical treatment of patients with oesophageal cancer

BACKGROUND

The availability of circulating biomarkers that are predictive of treatment response or prognostic of overall outcome could enable the personalised and adaptive use of radiotherapy (RT) in patients with oesophageal adenocarcinoma (OAC) and squamous cell carcinoma (OSCC).

METHODS

A systematic review was carried out following Preferred Reporting Items for Systematic Reviews guidance. Medline, EMBASE, PubMed, Cochrane Library, CINAHL, Scopus and the Web of Science databases were searched for studies published between January 2005-February 2023 relating to circulating biomarkers evaluated in the context of neoadjuvant or definitive RT delivered for OAC/OSCC. Study quality was assessed using predefined criteria.

RESULTS

A total of 3012 studies were screened and 57 subsequently included, across which 61 biomarkers were reported. A majority (43/57,75.4%) of studies were of Asian origin and retrospective (40/57, 70.2%), with most (52/57, 91.2%) biomarkers reported in the context of patients with OSCC. There was marked inter-study heterogeneity in patient populations, treatment characteristics, biomarker measurement and the cut points used to define biomarker positivity. Nevertheless, there is evidence for the prognostic and predictive value of circulating tumour DNA and numerous miRNAs in OAC and OSCC, as well as for the prognostic and predictive value of circulating levels of CYFRA21.1 in OSCC.

CONCLUSIONS

There is consistent evidence for the potential predictive and prognostic value of a small number of biomarkers in OSCC and OAC, though these data are insufficient for translation to current clinical practice. Well-designed prospective studies are now required to validate their role in stratified and personalised RT treatment approaches.

MicroRNAs: A novel signature in the metastasis of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a malignant epithelial tumor, characterized by squamous cell differentiation, it is the sixth leading cause of cancer-related deaths globally. The increased mortality rate of ESCC patients is predominantly due to the advanced stage of the disease when discovered, coupled with higher risk of metastasis, which is an exceedingly malignant characteristic of cancer, frequently leading to a high mortality rate. Unfortunately, there is currently no specific and effective marker to predict and treat metastasis in ESCC. MicroRNAs (miRNAs) are a class of small non-coding RNA molecules, approximately 22 nucleotides in length. miRNAs are vital in modulating gene expression and serve pivotal regulatory roles in the occurrence, progression, and prognosis of cancer. Here, we have examined the literature to highlight the intimate correlations between miRNAs and ESCC metastasis, and show that ESCC metastasis is predominantly regulated or regulated by genetic and epigenetic factors. This review proposes a potential role for miRNAs as diagnostic and therapeutic biomarkers for metastasis in ESCC metastasis, with the ultimate aim of reducing the mortality rate among patients with ESCC.