**Note 1:** This SSDI is effective for diagnosis years 2021+
* For cases diagnosed 2018-2020, leave this SSDI blank
**Note 2:** Physician statement of Ki-67 (MIB-1), also referred to as the “Proliferative Index” can be used to code this data item.
**Note 3:** Ki-67 is a marker of cell proliferation. A high value indicates a tumor that is proliferating more rapidly.
**Note 4:** Results from nodal or metastatic tissue may not be used.
* If the only information you have have is a Ki-67 from a metastatic site, code to XXX.9
**Note 5:** Ki-67 results are reported as the percentage cell nuclei that stain positive. As of early 2017, there are no established standards for interpretation of results or for cutoffs for positive and negative.
* *Example 1:* Ki-67 reported as 14%. Code 14.0
* *Example 2:* Ki-67 reported as 8.6%. Code 8.6
**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 Ki-67 results from pre-treatment specimens, report the findings from post-treatment specimens
**Note 7:** A specific value (0.0-100.0) takes priority over XXX.4, XXX.5 or XXX.6. Code the exact percentage when provided. When the exact percentage is not given, including ranges or terms such as “less than” or “greater than” use the range value codes XXX.4, XXX.5, XXX.6.
* XXX.4, XXX.5 and XXX.6 were added since they are listed on the CAP protocol
* *Example 1:* Ki-67 stated as less than 1%. Code XXX.4
* *Example 2:* Ki-67 stated as 5%-10%. Code XXX.5
* *Example 3:* Ki-67 stated as greater than 4%. Code XXX.5
* *Example 4:* Ki-67 stated as greater than 30%. Code XXX.6