KIT Gene Immunohistochemistry (IHC)
Description
KIT Gene Immunohistochemistry (IHC) is the expression of the KIT gene in tumor tissue specimens based on immunohistochemical (IHC) stains. A positive test is a diagnostic and predictive marker for GIST tumors.
KIT is a gene that regulates cell growth and differentiation. Mutations of this gene become oncogenes and cause a gastrointestinal stromal tumor to ignore cellular control signals. About 85-90% of GIST tumors contain oncogenic mutations of the KIT receptor gene. KIT immunohistochemistry is a special immunofluorescent stain that turns mutated cells brown and confirms a diagnosis of GIST. The presence of the KIT gene also indicates that the patient may respond to Gleevec or Sutent.
Rationale
KIT Gene Immunohistochemistry (IHC) is a Registry Data Collection Variable in AJCC. This data item was previously collected for GIST schemas in CS (different SSFs).
Additional Info
**Source documents:** pathology report (special stain)
**Other names include** CD117, c-kit receptor, KIT receptor tyrosine kinase, or SCFR (stem cell factor receptor)
Notes
**Note 1:** **Physician Statement**
* Physician statement of KIT IHC can be used to code this data item when no other information is available.
**Note 2:** **Results from nodal or metastatic tissue**
* May be used for KIT Gene immunohistochemistry
Default
8
Metadata
SSDI
| Code |
Description |
| 0 |
KIT negative/normal; within normal limits |
| 1 |
KIT positive |
| 7 |
Test ordered, results not in chart |
| 8 |
Not applicable: Information not collected for this case
(If this information is required by your standard setter, use of code 8 may result in an edit error.) |
| 9 |
Not documented in medical record
Cannot be determined by pathologist
KIT not assessed or unknown if assessed |
