title: Low-frequency microsatellite instability in genomic di-nucleotide sequences correlates with lymphatic invasion and poor prognosis in gastric cancer.
abstract: The clinical significance of low-frequency microsatellite instability (MSI-L) in gastric cancer (GC) has not been well established. The aim of this study was to evaluate the clinicopathological features of MSI-L in GC. We investigated microsatellite instability (MSI) in 5 di-nucleotide repeat sequences in 210 unselected GC patients. High-resolution fluorescent microsatellite analysis assay was utilized to detect MSI. Clinicopathological variables were compared among groups with different microsatellite statuses. The overall survival (OS) was analyzed by Kaplan-Meier method. Multivariable analysis was performed to identify prognostic factors and variables correlated with lymph node metastasis. High-frequency microsatellite instability (MSI-H), MSI-L, and microsatellite stable were identified, respectively, in 10.5, 10.0, and 79.5% of unselected GC cases. Tumors with MSI-H were less invasive, and these patients showed a better OS. MSI-L was correlated with more advanced tumor Node Metastasis stage, and more frequent lymph node metastasis. The unfavorable prognosis predicted by MSI-L was ascribed to its correlation with lymphatic invasion. MSI-L characterized by di-nucleotide markers represents a distinct subcategory of GC with aggressive clinicopathological features, which are particularly affiliated to lymphatic system and correlated with a poor prognosis. MSI-L could be beneficial for predicting the clinical outcome of GC.
authors.affiliation: Department of Stomach Surgery, Liaoning Cancer Hospital & Institute, 44 Xiaoheyan Road, Dadong District, Shenyang, Liaoning, 110042, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Zhi-Chao
authors.initials: ZC
authors.lastname: Zheng
authors.forename: Ya-Hong
authors.initials: YH
authors.lastname: Luo
authors.forename: Hao-Zhe
authors.initials: HZ
authors.lastname: Piao
authors.forename: Guo-Liang
authors.initials: GL
authors.lastname: Zheng
authors.forename: Jing-Yi
authors.initials: JY
authors.lastname: Shi
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018900:Dinucleotide Repeats; D005260:Female; D023281:Genomics; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D010641:Phenotype; D011379:Prognosis; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D016019:Survival Analysis