Data Last Updated: June 9, 2025

NAACCR Item #3852: HER2 ISH Dual Probe Ratio

Item # Length Source of Standard Section Name Year Implemented Version Implemented XML NAACCR ID Parent XML Element
3852 4 NAACCR Stage/Prognostic Factors 2018 18 her2IshDualProbeRatio Tumor
Required Status:

NPCR Collect: No recommendation
CoC Collect: No recommendation
SEER Collect: No recommendation
CCCR Collect: No recommendation

Description
HER2 in situ hybridization (ISH) Dual Probe Ratio is the summary score for HER2 testing using a dual probe. The test will report results for both HER2 and CEP17, the latter used as a control. The HER2/CEP17 ratio is reported.
Rationale
HER2 ISH Dual Probe Ratio is a Registry Data Collection Variable in AJCC. It is a new data item for cases diagnosed 1/1/2018+.
Allowable Values
0.0-99.9, XX.2, XX.3, XX.7, XX.8, XX.9
Codes
Code Description
0.0-99.9 Ratio of 0.0 to 99.9
XX.2 Less than 2.0
XX.3 Greater than or equal to 2.0
XX.7 Test ordered, results not in chart
XX.8 Not applicable: Information not collected for this case (If this item is required by your standard setter, use of code XX.8 will result in an edit error.)
XX.9 Not documented in medical record Results cannot be determined (indeterminate) Dual probe test not done; only single probe test performed HER2 ISH Dual Probe Ratio not assessed or unknown if assessed
Code Notes
Each Site-Specific Data Item (SSDI) applies only to selected primary sites, histologies, and years of diagnosis. Depending on applicability and standard-setter requirements, SSDIs may be left blank.