Sporadic early onset colorectal cancer in pakistan: A case-control analysis of microsatellite instability

Sabeehuddin Siddique, Kanwal Tariq, Sobia Rafiq, Ahmed Raheem, Rashida Ahmed, Munira Shabbir-Moosajee, Kulsoom Ghias

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


Background: Early onset sporadic colorectal cancer (CRC) is a biologically and clinically distinct entity hypothesized to exhibit differences in histological features and microsatellite instability (MSI) as compared to typical onset CRC. This study compared the MSI status, mismatch repair enzyme deficiency and clinicopathological features of early onset (aged ≤45 years) with controls (>45 years). Materials and Methods: A total of 30 cases and 30 controls were analyzed for MSI status using the Bethesda marker panel. Using antibodies against hMLH1, hMSH2 and hMSH6, mismatch repair protein expression was assessed by immunohistochemistry. Molecular characteristics were correlated with clinicopathological features. Results: The early onset sporadic CRCs were significantly more poorly differentiated tumors, with higher N2 nodal involvement and greater frequency of signet ring phenotype than the typical onset cases. MSI was observed in 18/30 cases, with 12/18 designated as MSI-high (MSI-H) and 6/18 designated as MSI-low (MSI-L). In the control group, 14 patients exhibited MSI, with 7 MSI-H and 7 MSI-L. MSI tumors in both cases and controls exhibited loss of hMLH1, hMSH2 and hMSH6. MSS tumors did not exhibit loss of expression of MMR proteins, except hMLH1 protein in 3 controls. No statistically significant difference was noted in MSI status or expression of MMR proteins in cases versus controls. Conclusions: Microsatellite status is comparable between early and typical onset sporadic CRC patients in Pakistan suggesting that differences in clinicopathological features between these two subsets are attributable to other molecular mechanisms.

Original languageEnglish
Pages (from-to)2587-2592
Number of pages6
JournalAsian Pacific Journal of Cancer Prevention
Issue number5
Publication statusPublished - 1 Jun 2016


  • Colorectal cancer
  • Early onset
  • Microsatellite instability
  • Mismatch repair


Dive into the research topics of 'Sporadic early onset colorectal cancer in pakistan: A case-control analysis of microsatellite instability'. Together they form a unique fingerprint.

Cite this