Clinicopathological and molecular characteristics of serrated lesions in Japanese elderly patients

Katsuhiko Nosho, Hisayoshi Igarashi, Miki Ito, Kei Mitsuhashi, Hiroyoshi Kurihara, Shinichi Kanno, Shinji Yoshii, Masashi Mikami, Hiroaki Takahashi, Takaya Kusumi, Masao Hosokawa, Yasutaka Sukawa, Yasushi Adachi, Tadashi Hasegawa, Kenji Okita, Koichi Hirata, Reo Maruyama, Hiromu Suzuki, Kohzoh Imai, Hiroyuki YamamotoYasuhisa Shinomura

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


Background: 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. Methods: 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 BRAF and KRAS mutations, CpG island methylator phenotype-specific promoters (CACNA1G, CDKN2A, IGF2 and RUNX3), IGFBP7, MGMT, MLH1 and RASSF2 methylation, microsatellite instability (MSI) and microRNA- 31 (miR-31). Results: 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, MLH1 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. Conclusion: 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.

Original languageEnglish
Pages (from-to)57-63
Number of pages7
Issue number1
Publication statusPublished - 2015 Feb 6


  • Aging
  • Colonoscopy
  • Colorectal cancer
  • Hyperplastic polyp

ASJC Scopus subject areas

  • Gastroenterology


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