, Volume 22, Issue 7, pp 739-748
Date: 16 Nov 2006

The role of chemotherapy in microsatellite unstable (MSI-H) colorectal cancer

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access



High-frequency microsatellite instability (MSI-H) is an alternate pathway of colorectal carcinogenesis, which accounts for 15% of all sporadic colorectal cancers. These tumours arise from mutations in the DNA mismatch repair system and thus have different responses to chemotherapeutic agents compared to microsatellite stable (MSS) cancers.


This review aims to summarise the available literature on the responses to chemotherapy in MSI-H colorectal cancer (CRC).

Results and discussion

5 Fluorouracil (5FU) is commonly used as a chemotherapeutic agent in colon cancer and in vitro evidence shows reduced response to 5FU in MSI-H CRC. The clinical evidence is conflicting but favours a reduced response to 5FU in MSI-H CRC. Several newer agents such as COX-2 inhibitors and irinotecan are also reviewed.


Available evidence suggests that MSI-H CRC have different behaviour patterns and response to chemotherapy compared with MSS CRC.