MSI Analysis in Solid and Liquid Biopsies of Gastroesophageal Adenocarcinoma Patients: A Molecular Approach.
Int J Mol Sci
; 22(14)2021 Jul 06.
Article
in En
| MEDLINE
| ID: mdl-34298864
ABSTRACT
Gastroesophageal adenocarcinoma (GEA) patients with the microsatellite instability (MSI) subtype emerged as optimal candidates for immunotherapy. To date, immunohistochemistry (IHC) is the gold standard for MSI assessment in formalin-fixed paraffin-embedded (FFPE) specimens. However, IHC, although useful for diagnostic typing, cannot be used to analyze cell-free DNA (cfDNA) in liquid biopsy, a tool that could overcome tumor heterogeneity and enable longitudinal monitoring. In order to find an alternative diagnostic method to IHC, we analyzed 86 retrospective GEAs FFPE samples with multiplex PCR. Moreover, to verify the feasibility of MSI detection in liquid biopsy, cfDNA samples of five patients that resulted in having MSI in a prospective cohort of 35 patients were evaluated by multiplex PCR, real-time PCR and droplet digital PCR (ddPCR). Analysis of FFPE showed 100% concordance between multiplex PCR and IHC (Cohen's Kappa agreement = 1). On the contrary, only ddPCR was able to detect MSI in cfDNAs of T3/T4 GEA patients. In conclusion, data highlight the molecular analysis as an optimal alternative to IHC for the diagnostic typing and suggest that the ddPCR assay can be considered as the most reliable and promising molecular approach to detect MSI in the cfDNA of GEA patients.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Stomach Neoplasms
/
Esophageal Neoplasms
/
Adenocarcinoma
/
Esophagogastric Junction
Type of study:
Observational_studies
Limits:
Adult
/
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Int J Mol Sci
Year:
2021
Document type:
Article
Affiliation country:
Italy