Details

Autor(en) / Beteiligte

• BOARDMAN, Lisa A
• JOHNSON, Ruth A
• LINDOR, Noralane M
• THIBODEAU, Stephen N
• PETERSEN, Gloria M
• OBERG, Ann L
• KABAT, Brian F
• SLUSSER, Joshua P
• LIANG WANG
• MORLAN, Bruce W
• FRENCH, Amy J
• SMYRK, Thomas C

Titel

Higher Frequency of Diploidy in Young-Onset Microsatellite-Stable Colorectal Cancer

Ist Teil von

• Clinical cancer research, 2007-04, Vol.13 (8), p.2323-2328

Ort / Verlag

Philadelphia, PA: American Association for Cancer Research

Erscheinungsjahr

2007

Quelle

MEDLINE

Beschreibungen/Notizen

• Purpose: Colorectal carcinoma (CRC) can be divided into two nonoverlapping groups: those that are chromosomally unstable but microsatellite stable (MSS CIN+) and those that are chromosomally stable but microsatellite unstable (MSI CIN−). However, a third group with neither chromosome nor microsatellite instability (MSS CIN−) makes a substantial contribution to the total CRC burden. The clinicopathologic features of MSS CIN− CRC are not well delineated. We assessed the relationship between age and chromosomal instability (CIN) status as measured by ploidy and allelic imbalance in a series of MSS tumors. Experimental Design: We studied a prospectively collected series of CRC patients at Mayo Clinic Rochester. A total of 84 samples of MSS CRC in patients ≤50 years old were identified between 1994 and 1997. A consecutive series of 90 MSS CRC in patients ≥65 years old served as a comparison group. CIN status was assessed using two techniques: ploidy analysis by flow cytometry and small chromosome changes as measured by genomewide fractional allelic imbalance. Results: CRC in the young-onset group was more likely to involve the rectum and to be high stage. MSS tumors in the young-onset group were more often diploid (46%) than those in older patients (26%; P = 0.006). This difference was maintained in the subset of MSS CRC that were high stage (42% versus 18%; P = 0.02) and in rectal cancers (50% versus 23%; P = 0.04). Conclusion: A greater proportion of young patients with MSS CRC has diploid tumors than patients who develop MSS CRC over age 65.