In:
Digestion, S. Karger AG, Vol. 91, No. 1 ( 2015), p. 57-63
Abstract:
〈 b 〉 〈 i 〉 Background: 〈 /i 〉 〈 /b 〉 The population in Japan is aging more rapidly than in any other country. However, no studies have determined the characteristics of the large population of elderly patients with colorectal tumors. Therefore, we examined the clinicopathological and molecular features of these tumors in elderly patients. 〈 b 〉 〈 i 〉 Methods: 〈 /i 〉 〈 /b 〉 In total, 1,627 colorectal tumors (393 serrated lesions, 277 non-serrated adenomas and 957 colorectal cancers) were acquired from patients. Tumor specimens were analyzed for 〈 i 〉 BRAF 〈 /i 〉 and 〈 i 〉 KRAS 〈 /i 〉 mutations, CpG island methylator phenotype-specific promoters 〈 i 〉 (CACNA1G 〈 /i 〉 , 〈 i 〉 CDKN2A 〈 /i 〉 , 〈 i 〉 IGF2 〈 /i 〉 and 〈 i 〉 RUNX3) 〈 /i 〉 , 〈 i 〉 IGFBP7 〈 /i 〉 , 〈 i 〉 MGMT 〈 /i 〉 , 〈 i 〉 MLH1 〈 /i 〉 and 〈 i 〉 RASSF2 〈 /i 〉 methylation, microsatellite instability (MSI) and microRNA- 31 (miR-31). 〈 b 〉 〈 i 〉 Results: 〈 /i 〉 〈 /b 〉 The frequency of elderly patients (aged ≥75 years) with sessile serrated adenomas (SSAs) with cytological dysplasia was higher than that of those with other serrated lesions and non-serrated adenomas (p 〈 0.0001). In elderly patients, all SSAs were located in the proximal colon (particularly the cecum to ascending colon). High miR-31 expression, 〈 i 〉 MLH1 〈 /i 〉 methylation and MSI-high status were more frequently detected in SSAs from elderly patients than in those from non-elderly patients. In contrast, no significant differences were found between older age of onset and high-grade dysplasia for traditional serrated adenomas or non-serrated adenomas in any of these molecular alterations. 〈 b 〉 〈 i 〉 Conclusion: 〈 /i 〉 〈 /b 〉 In elderly patients, all SSAs were located in the proximal colon. Furthermore, cytological dysplasia and molecular alterations were more frequently detected in elderly patients with SSAs than in non-elderly patients. Thus, careful colonoscopic examinations of the proximal colon are necessary for elderly patients because SSAs in those patients may exhibit malignant potential.
Type of Medium:
Online Resource
ISSN:
0012-2823
,
1421-9867
Language:
English
Publisher:
S. Karger AG
Publication Date:
2015
detail.hit.zdb_id:
1482218-0
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