MSI-low, a real phenomenon which varies in frequency among cancer types.
This study assessed whether low-level microsatellite instability (MSI-L) is a phenomenon specific to colorectal cancers or is also present in other tumour types. Breast (grade III ductal and lobular), endometrial and ovarian carcinomas, as well as colorectal cancers, were analysed for MSI-L using eight microsatellite markers. The markers were selected from a panel that had previously been shown to be sensitive for the detection of MSI-L in colorectal cancers. It was found that MSI-L was present in 30 of 87 (35%) colorectal cancers, 2 of 59 (3%) grade III breast carcinomas, 1 of 35 (3%) lobular breast cancers, 16 of 50 (32%) endometrial cancers, and 9 of 34 (26%) ovarian cancers. These results suggest that MSI-L is a very rare occurrence in breast carcinomas, but does occur as a real phenomenon in colorectal, endometrial, and ovarian carcinomas, which are all part of the hereditary non-polyposis colon cancer (HNPCC) syndrome. PCR artefact was also found to masquerade as MSI-L; criteria for the assessment of MSI-L are suggested to eliminate this problem.
Molecular and Population Genetics Laboratory, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3PX, UK.
Sarah E R
SE
Halford
Elinor J
EJ
Sawyer
Maryou B
MB
Lambros
Patricia
P
Gorman
Nicola D
ND
Macdonald
Ian C
IC
Talbot
William D
WD
Foulkes
Cheryl E
CE
Gillett
Diana M
DM
Barnes
Lars A
LA
Akslen
Kwok
K
Lee
Ian J
IJ
Jacobs
Andrew M
AM
Hanby
Trivadi S
TS
Ganesan
Helga B
HB
Salvesen
Walter F
WF
Bodmer
Ian P M
IP
Tomlinson
Rebecca R
RR
Roylance
D014408:Biomarkers, Tumor / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics*; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics; D016889:Endometrial Neoplasms / Q000235:genetics*; D005260:Female; D005819:Genetic Markers / Q000235:genetics; D006801:Humans; D018895:Microsatellite Repeats / Q000235:genetics*; D009367:Neoplasm Staging; D010051:Ovarian Neoplasms / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods
D014408:Biomarkers, Tumor; D005819:Genetic Markers