Author/Authors :
Bavi, Prashant P. King Faisal Specialist Hospital and Research Centre - Department of Human Cancer Genomic Research, Saudi Arabia , Abubaker, Jehad A. King Faisal Specialist Hospital and Research Centre - Department of Human Cancer Genomic Research, Saudi Arabia , Jehan, Zeenath D. King Faisal Specialist Hospital and Research Centre - Department of Human Cancer Genomic Research, Saudi Arabia , Al-Jomah, Naif A. King Faisal Specialist Hospital and Research Centre - Department of Human Cancer Genomic Research, Saudi Arabia , Siraj, Abdul K. King Faisal Specialist Hospital and Research Centre - Department of Human Cancer Genomic Research, Saudi Arabia , Al-Harbi, Sayer R. King Faisal Specialist Hospital and Research Centre - Department of Human Cancer Genomic Research, Saudi Arabia , Atizado, Valerie L. King Faisal Specialist Hospital and Research Centre - Department of Human Cancer Genomic Research, Saudi Arabia , Abduljabbar, Alaa S. King Faisal Specialist Hospital and Research Centre - Colorectal Unit - Department of Research Centre, Saudi Arabia , Alhomoud, Samar J. King Faisal Specialist Hospital and Research Centre - Colorectal Unit - Department of Research Centre, Saudi Arabia , Ashari, Luai H. King Faisal Specialist Hospital and Research Centre - Colorectal Unit - Department of Research Centre, Saudi Arabia , Al-Dayel, Fouad H. King Faisal Specialist Hospital and Research Centre - Department of Surgery, Saudi Arabia , Uddin, Shahab King Faisal Specialist Hospital and Research Centre - Department of Human Cancer Genomic Research, Saudi Arabia , Al-Kuraya, Khawla S. King Faisal Specialist Hospital and Research Centre - Department of Human Cancer Genomic Research, Saudi Arabia , Alsanea, Nasser A. King Faisal Specialist Hospital and Research Centre - Colorectal Unit - Department of Research Centre, Saudi Arabia
Abstract :
Objectives: 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.
