Immunogenic characteristics of microsatellite instability-low esophagogastric junction adenocarcinoma based on clinicopathological, molecular, immunological and survival analyses.
Int J Cancer
; 148(5): 1260-1275, 2021 03 01.
Article
em En
| MEDLINE
| ID: mdl-32997798
ABSTRACT
Microsatellite instability (MSI) is categorized by mutation frequency high MSI (MSI-H), low MSI (MSI-L) and microsatellite stable (MSS). MSI-H tumors have a distinct immunogenic phenotype, with immunotherapies using checkpoint inhibitors already approved for the treatment of MSI-H gastroesophageal adenocarcinoma (GEA); this is not observed for MSI-L or MSS. Here, we tested the hypothesis that MSI-L tumors are also a distinct phenotype and potentially immunogenic. MSI-PCR assays (BAT25, BAT26, BAT40, D2S123, D5S346 and D17S250) were performed on 363 Epstein-Barr virus-negative, surgically resected esophagogastric junction (EGJ) adenocarcinoma samples. Tumors were characterized as MSI-H (≥2 markers), MSI-L (1 marker) or MSS (0 markers). CD8+ cell counts, PD-L1 and HER2 expression levels, TP53 mutations, epigenetic alterations and prognostic significance were also examined. All pathological and molecular experiments were conducted using serial, whole-tumor sections of chemo-naïve surgical specimens. MSI-H and MSI-L were assigned to 28 (7.7%) and 24 (6.6%) cases, respectively. Compared to MSS cases, MSI-L cases had significantly higher intratumoral CD8+ cell infiltration (P = .048) and favorable EGJ cancer-specific survival (multivariate hazard ratio = 0.35, 95% CI, 0.12-0.82; P = .012). MSI-L tumors were also significantly associated with TP53-truncating mutations as compared to MSI-H (P = .009) and MSS (P = .012) cases, and this trend was also observed in GEA data from The Cancer Genome Atlas (TCGA). Indel mutational burden among TCGA MSI-L tumors was significantly higher than that of MSS tumors (P = .016). These results suggest that MSI-L tumors may have a distinct tumor phenotype and be potentially immunogenic in EGJ adenocarcinoma.
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Texto completo:
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Bases de dados:
MEDLINE
Assunto principal:
Neoplasias Esofágicas
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Adenocarcinoma
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Junção Esofagogástrica
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Instabilidade de Microssatélites
Tipo de estudo:
Prognostic_studies
Limite:
Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Int J Cancer
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Japão