Site-Specific Factor 7

KIT Gene Mutations


**Note 1:** This is a special molecular diagnostic test performed on tumor tissue to identify mutations in specific parts (called exons) of the KIT gene. Certain patterns of mutations correlate with the anatomic site and morphology of gastrointestinal stromal tumors (GISTs) tumors and can predict response to treatment with agents such as imatinib mesylate (Gleevec) and sunitinib malate (Sutent). Some mutations are associated with acquired resisteance to imatinib treatment; do not record secondary or acquired mutations that may have been caused by long-term imatinib treatment. **Note 2:** Code the mutation locations found from the KIT gene test. Another name for KIT is CD117. **Note 3:** See **Site-Specific Factor 6, KIT Gene Immunohistochemistry (IHC)** for coding information about KIT expression detected with immunohistochemistry (IHC).  See **Site-Specific Factor 8, PDGFRA Gene Mutation** for coding information about mutations of the PDGFRA gene.




NAACCR #2861
Code Description
000 KIT gene test negative for mutations; no mutations; normal or wild-type gene
010 KIT gene test positive for mutation of exon 9 only
020 KIT gene test positive for mutation of exon 11 only
030 KIT gene test positive for mutation of exon 13 only
040 KIT gene test positive for mutation of exon 17 only
800 KIT gene test positive for one other specified mutation
810 KIT gene test performed, positive for more than one specific mutation
850 KIT gene test positive, NOS; mutation(s) found but the specific mutation(s) are not stated
988 Not applicable: Information not collected for this case
997 Test ordered, results not in chart; results pending
998 Test not done (test not ordered and not performed)
999 Unknown or no information
Not documented in patient record