Collaborative Stage

Note: The microsatellite instability (MSI) test is a genetic test performed on tumor tissue to look for differences in length of certain non-functioning sections of deoxyribonucleic acid (DNA). The differences are caused by problems with the genes that normally repair DNA. A high-positive MSI (MSI-H) result may indicate that the gene repair problem is related to the development of the cancer, and that the patient may have hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome. A low-positive or stable MSI result (stable meaning that there are no differences in the lengths) means it is unlikely that the cancer is related to a hereditary condition.

Code	Description
020	Microsatellite instability (MSI) stable; no MSI
040	MSI unstable low; positive, low
050	MSI unstable high; positive, high
060	MSI unstable, NOS; positive, NOS
888	OBSOLETE DATA CONVERTED V0200 See code 988 Not applicable for this site
988	Not applicable: Information not collected for this case (May include cases converted from code 888 used in CSv1 for "Not applicable" or when the item was not collected. If this item is required to derive T, N, M, or any stage, use of code 988 may result in an error.)
997	Test ordered, results not in chart
998	Test not done (test not ordered and not performed)
999	Unknown or no information Not documented in patient record

CS Site-Specific Factor 5
Microsatellite Instability