Gastric cancer is a type of cancer that initiates from the cells in the lining of the stomach. Different factors, such as environmental and inheritance, can increase the risk of developing gastric cancer. Accumulation of mutations can result in the transformation of healthy cells into cancerous cells that will divide uncontrollably forming a tumor mass. At advanced stages, the tumor can release circulating tumor DNA (ctDNA) in the blood which will contain all the genetic alterations responsible for cancer initiation and development. Identifying the genetic alterations in the ctDNA has many benefits, including better prognostic assessment as well as therapy selection guidance which is tailored to each patient.
Microsatellite instability (MSI) immunotherapy biomarker assessment is also included in this panel and has been shown to be implicated in gastric cancer. Evidence suggests that MSI high status is correlated with better prognosis in patients with gastric cancer as well as improved survival rates. The FDA/EMA approved drug pembrolizumab can be used as an immunotherapy option for MSI-high patients with gastric cancer.
How many genes are tested in this panel?
Recommendations by professional bodies
ESMO recommends liquid biopsy testing for ERBB2 gene in patients with gastric cancer when tissue biopsy is not feasible or when fast results are necessary for therapy selection (Pascual et al., 2022; ESMO recommendations).
References and more information:
• Information obtained from professional bodies including National Cancer Institute, and World Cancer Research Fund International
• Pascual J, Attard G, Bidard FC, Curigliano G, De Mattos-Arruda L, Diehn M, Italiano A, Lindberg J, Merker JD, Montagut C, Normanno N, Pantel K, Pentheroudakis G, Popat S, Reis-Filho JS, Tie J, Seoane J, Tarazona N, Yoshino T, Turner NC. ESMO recommendations on the use of circulating tumour DNA assays for patients with cancer: a report from the ESMO Precision Medicine Working Group. Ann Oncol. 2022 Aug;33(8):750-768. doi: 10.1016/j.annonc.2022.05.520. Epub 2022 Jul 6. PMID: 35809752.
• Ratti M, Lampis A, Hahne JC, Passalacqua R, Valeri N. Microsatellite instability in gastric cancer: molecular bases, clinical perspectives, and new treatment approaches. Cell Mol Life Sci. 2018 Nov;75(22):4151-4162. doi: 10.1007/s00018-018-2906-9. Epub 2018 Sep 1. PMID: 30173350; PMCID: PMC6182336.
• Polom K, Marrelli D, Smyth EC, Voglino C, Roviello G, Pascale V, Varas J, Vindigni C, Roviello F. The Role of Microsatellite Instability in Positive Margin Gastric Cancer Patients. Surg Innov. 2018 Apr;25(2):99-104. doi: 10.1177/1553350617751461. Epub 2018 Jan 5. PMID: 29303062.