Colorectal carcinomas from Middle East. Molecular and tissue microarray analysis of genomic instability pathways.

Abstract

OBJECTIVE:

To evaluate the overall incidence of microsatellite instability (MSI), hereditary non polyposis colorectal cancer, and tumor supressor gene (TP53) mutations in Saudi colorectal carcinomas.

METHODS:

We studied the MSI pathway in Saudi colorectal cancers (CRC) from 179 unselected patients using 2 methods: MSI by polymerase chain reaction, and immunohistochemistry detection of mutL homologs 1 and mutS homologs 2 proteins. The TP53 mutations were studied by sequencing exons 5, 6, 7, and 8.

RESULTS:

Of the 150 colorectal carcinomas analyzed for MSI, 16% of the tumors showed high level instability (MSI-H), 19.3% had low-level instability (MSI-L) and the remaining 64% tumors were stable. Survival of the MSI-H group was better as compared to the MSI-L or microsatellite stable group (p=0.0217). In the MSI-H group, 48% were familial MSI tumors, which could be attributable to the high incidence of consanguinity in the Saudi population. The TP53 mutations were found in 24% of the cases studied.

CONCLUSION:

A high proportion of familial MSI cases and a lower incidence of TP53 mutations are some of the hallmarks of the Saudi colorectal carcinomas, which need to be explored further.

• Authors: Prashant P Bavi, Jehad A Abubaker, Zeenath D Jehan, Naif A Al-Jomah, Abdul K Siraj, Sayer R Al-Harbi, Valerie L Atizado, Alaa S Abduljabbar, Samar J Alhomoud, Luai H Ashari, Fouad H Al-Dayel, Shahab Uddin, Khawla S Al-Kuraya, Nasser A Alsanea
• Journal: Saudi medical journal (Saudi Med J) Vol. 29 Issue 1 Pg. 75-80 (Jan 2008) ISSN: 0379-5284 [Print] Saudi Arabia
• PMID: 18176677 (Publication Type: Journal Article)

Chemical References

• Genetic Markers

Topics

• Chi-Square Distribution
• Colorectal Neoplasms, Hereditary Nonpolyposis (epidemiology, ethnology, genetics)
• Genes, p53 (genetics)
• Genetic Markers
• Genetics, Population
• Humans
• Immunohistochemistry
• Incidence
• Microarray Analysis
• Microsatellite Instability
• Mutation
• Pilot Projects
• Polymerase Chain Reaction
• Saudi Arabia (epidemiology)