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Mucinous carcinomas of the colon and rectum show higher rates of microsatellite instability and lower rates of chromosomal instability
A study matched for T classification and tumor location
Article first published online: 5 APR 2005
Copyright © 2005 American Cancer Society
Volume 103, Issue 10, pages 2023–2029, 15 May 2005
How to Cite
Kazama, Y., Watanabe, T., Kanazawa, T., Tada, T., Tanaka, J. and Nagawa, H. (2005), Mucinous carcinomas of the colon and rectum show higher rates of microsatellite instability and lower rates of chromosomal instability. Cancer, 103: 2023–2029. doi: 10.1002/cncr.21022
- Issue published online: 28 APR 2005
- Article first published online: 5 APR 2005
- Manuscript Accepted: 10 JAN 2005
- Manuscript Revised: 26 DEC 2004
- Manuscript Received: 3 SEP 2004
- mucinous carcinoma;
- colorectal cancer;
- microsatellite instability;
- chromosomal instability;
- T classification;
- tumor location
The clinicopathologic significance of mucinous carcinomas (Muc) of the colon and rectum has been widely discussed, but there have been few studies on Muc regarding genetic and epigenetic alterations. The current study analyzed genetic and epigenetic alterations of Muc to clarify their differences from well differentiated adenocarcinomas (WD).
Thirty-nine cases of Muc and 39 cases of WD were investigated. Cases of WD were matched with cases of Muc for T classification and tumor location. Microsatellite instability (MSI) status and loss of heterozygosity (LOH) of four loci (2p, 5q, 17p, 18q) were evaluated. The methylation status of the hMLH1 promoter region in Muc was also examined.
“MSI tumors” were defined as those that showed MSI-high, and “chromosomal instability (CIN) tumors” were defined as those that showed LOH but not MSI-high. MSI tumors were significantly more frequent in Muc (30.8%) than in WD (5.1%). CIN tumors were significantly less frequent in Muc (53.8%) than in WD (87.2%). In Muc, MSI tumors were significantly more frequent in the proximal colon (55.6%) than in the distal colon (9.5%). Also, methylation of the hMLH1 promoter region in Muc was significantly more frequent in MSI tumors (83.3%) than in CIN tumors (27.8%) (P = 0.0077).
When matched for T classification and tumor location, Muc shows higher rates of MSI and lower rates of CIN than WD.. Muc shows different characteristics according to tumor location, and methylation of the hMLH1 promoter region strongly correlates with Muc tumors showing MSI. Cancer 2005. © 2005 American Cancer Society.