The Microsatellite Instability (MSI) PCR assay is intended to be used as a screening test for Lynch Syndrome (hereditary nonpolyposis colorectal cancer syndrome). This test will be a reflex test on resection specimens from ALL individuals with new histologically diagnosed colorectal cancer (CRC) from SGH and NCC (including NCC at CGH).
Paraffin embedded tissue blocks sent to the Histopathology Section.
Alternatively, unstained slides can be sent to the Histopathology Section. At least 8 sections of 8 µm thickness (or 12 sections of 5 µm thickness for smaller samples) each of both tumour and normal tissue, should be sent together with one H&E slide, 4 µm thick with a coverslip as a reference slide. Tumour content must be indicated and preferably at least 50% (samples with less than 30% tumour will be rejected).
In-house developed Multiplexed Polymerase Chain Reaction (PCR) with fragment length analyses for 5 quasi-monomorphic mononucleotide repeats (BAT25, BAT26, NR21, NR24 and NR27)
Microsatellite stable, Microsatellite Unstable, Inconclusive
Mondays and Thursdays