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Clinicopathologic characteristics and outcomes of gastric cancers with the MSI‐H phenotype
Author(s) -
Seo Hyung Min,
Chang Yeon Soo,
Joo Sun Hyung,
Kim Youn Wha,
Park YongKoo,
Hong Sung Wha,
Lee SukHwan
Publication year - 2008
Publication title -
journal of surgical oncology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.201
H-Index - 111
eISSN - 1096-9098
pISSN - 0022-4790
DOI - 10.1002/jso.21220
Subject(s) - microsatellite instability , immunohistochemistry , pathology , medicine , staining , cancer , lymphovascular invasion , dna mismatch repair , biology , colorectal cancer , microsatellite , metastasis , gene , biochemistry , allele
Objectives We examined the correlation between microsatellite instability (MSI) status and the clinicopathological features and prognostic value in gastric cancer and compared the efficacy of immunohistochemical staining for hMLH1 and hMSH2 with a polymerase chain reaction (PCR)‐based test. Methods MSI status was examined in 328 consecutive gastric adenocarcinomas using tissue preserved in paraffin blocks. DNA extracted from tumor sections and the corresponding normal tissue was analyzed using PCR at the five microsatellite loci recommended by the National Cancer Institute (NCI). Immunohistochemical staining for hMLH1 and hMSH2 was performed and the results were compared with the MSI status measured using PCR. The relationship of the clinicopathologic variables to MSI status was analyzed. Results Of the gastric cancers, 8.2% (n = 27) contained MSI‐H and this was associated with older age (>70 years), distal tumor location, tumor size, and intestinal subtype. Lymphatic and vascular invasion were associated with the disease‐free survival. On immunohistochemical staining, the loss of expression of hMLH1 or hMSH2 was observed in 11% (n = 36). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of immunohistochemical staining were 63.0%, 93.7%, 47.2%, 96.6%, and 91.2%, respectively. Conclusions Gastric cancers with MSI‐H have specific clinicopathologic characteristics, such as older age at diagnosis, distal tumor location, increased tumor size, and intestinal histologic type. However, immunohistochemical staining for hMLH1 and hMSH2 is not as accurate as the PCR‐based MSI test. J. Surg. Oncol. 2009;99: 143–147. © 2008 Wiley‐Liss, Inc.