Table 1.

Tissue-based methods for MSI screening to distinguish sporadic tumours from lynch syndrome.

Method	Advantages	Limitations
IHC	Workflow takes up to 4–6 h	Analysis of MMR proteins separately
	Easy to perform	Needs a pathologist with experience in MMR IHC interpretation
	Performable in samples with <20% neoplastic cells Able to identify defective MMR genes for downstream analysis	Equivocal test results due to the heterogeneous expression of MMR proteins False-positive results (artificial loss of expression) due to pre-analytic issues or lack of technical calibration Rare false-negative results if there is no apparent loss of expression due to missense mutations in the MMR genes with intact immunoreactivity in approximately 10% of all cases Not reliable in small biopsy specimens Sensitivity depends on antibody panel
MSI-PCR	Allows simultaneous detection of multiple targets	No indication about MMR genes
	Highly reproducible Workflow takes less than 5 h	Requires samples with at least 20% neoplastic cells Rare false-positive results due to microsatellite polymorphisms Informative only for a few tumour types Limited number of markers