**Note 1:** This SSDI is effective for diagnosis years 2021+
* For cases diagnosed 2018-2020, leave this SSDI blank
**Note 2:** Physician statement of ALK rearrangement for non-small cell carcinoma can be used to code this data item when no other information is available.
**Note 3:** ALK may be recorded for all histologies and stages; however, it is primarily performed for advanced non-small cell carcinomas. If information is not available, code 9.
**Note 4:** The absence or presence of ALK protein expression determines if the tumor will respond to treatment with a targeted inhibitor. ALK protein expression predicts the ALK rearrangement gene, which are more likely to respond to the targeted inhibitor treatment. The most common ALK rearrangements are
**Note 5:** If ALK Rearrangement is positive and there is no mention of the specific rearrangement, code 4.
**Note 6:** If neoadjuvant therapy is given, record the assay from tumor specimens prior to neoadjuvant therapy.
* If neoadjuvant therapy is given and there are no ALK results from pre-treatment specimens, report the findings from post-treatment specimens
**Note 7:** Code 9 when
* Insufficient amount of tissue available to perform test
* Test done and documented to be equivocal
* No microscopic confirmation of tumor
* ALK Rearrangement not ordered or not done, or unknown if ordered or done