Noncoding RNA promising gastric-cancer biomarker

Last Updated: 2020-06-19

By David Douglas

NEW YORK (Reuters Health) - Circulating exosomal gastric-cancer-associated long noncoding RNA1 (lncRNA-GC1) may be a useful aid in managing patients with the disease, according to researchers in China.

"Accompanied with endoscopy, detection of circulating exosomal lncRNA-GC1 may improve the early diagnostic rate in patients with gastric cancer and monitor disease progression," Dr. Lin Chen of the Chinese People's Liberation Army General Hospital, in Beijing, told Reuters Health by email.

The current standard for diagnosing gastric cancer is endoscopic biopsy, Dr. Chen and colleagues note in JAMA Surgery. However, they add, because of patient discomfort and high cost, screening for early GC presents major difficulties in clinical practice, particularly for asymptomatic patients.

Moreover, standard screening tests such as for carcinoembryonic antigen (CEA) have a low positive rate. Another approach may be detection of lncRNA-GC1, which is known to be involved in the progression of gastric cancer, in circulating exosomes, the researchers say.

Between 2016 and 2019, the team studied 522 patients with GC, 85 with gastric precancerous lesions and 219 healthy donors. Most (61.5%) were men and their median age was 60 years.

lncRNA-GC1 achieved better diagnostic performance than standard biomarkers such as CEA in distinguishing between the patients with GC and healthy donors (area under the curve, 0.9033). In addition, compared with those in normal gastric epithelial cells, levels were significantly higher in culture media from GC cells.

The team found that lncRNA-GC1 retained its diagnostic efficiency in discriminating patients with GC from those with gastric precancerous lesions as well as from healthy donors. The approach also showed success in patients with GC who had negative standard biomarkers.

In addition, independent of pathological grading and Lauren classification, levels of circulating exosomal lncRNA-GC1 were significantly associated with GC from early to advanced stages, suggesting that they "may accurately reflect the progression of GC."

The researchers also determined that in 49 patients with GC who underwent neoadjuvant chemotherapy, 75.5% showed decreased levels of lncRNA-GC1. The team concludes that their "results shed new light on the measurement of neoadjuvant chemotherapy."

In an accompanying editorial Dr. David L. Bartlett of the University of Pittsburgh Medical Center notes that the new data "are impressive but need corroboration with a larger cohort followed up sequentially to understand the true correlation with disease burden in a single patient over time."

He also cautions that circulating nucleotide biomarkers have been described in the past with sensitivity and specificity values higher than those currently described "and these have not moved forward into clinical practice."

The study had no commercial funding, and the researchers report no conflicts of interest.

SOURCE: https://bit.ly/2UVU6mR and https://bit.ly/2AKW6rf JAMA Surgery, online June 10, 2020.