Additional Information:
HER2 Interpretation |
Staining Intensity Score |
Surgical Resections |
Biopsies |
---|---|---|---|
Negative | 0 | No reactivity or membranous reactivity in < 10% of tumor cells |
No reactivity or membranous reactivity in < 5 clustered tumor cells |
Negative* (*reflex FISH) |
1+ (40x) | Faint/barely perceptible membranous reactivity in > 10% of tumor cells; cells are reactive only in part of their membrane |
Tumor cell cluster (> 5 cells) with a faint/barely perceptible membranous reactivity irrespective of percentage of tumor cells stained. |
Equivocal* (*reflex FISH) |
2+ (10 - 20x) | Weak-to-moderate complete, basolateral or lateral membranous reactivity in > 10% of tumor cells |
Tumor cell clusters (> 5 cells) with a weak to moderate complete, basolateral or lateral membranous reactivity irrespective or percentage of tumor cells stained. |
Positive | 3+ (2.5 – 5x) | Strong complete, basolateral or lateral membranous reactivity in > 10% of tumor cells |
Tumor cell clusters (> 5 cells) with a strong complete, basolateral or lateral membranous reactivity irrespective of percentage of tumor cells stained. |
References:
|
CPT Code(s):
- 88360 FISH reflex
- 88368 x 2
Specimen Requirements:
A paraffin block containing the representative gastric/GE junction tumor or at least 5 unstained slides
Unacceptable Conditions: Frozen
Stability: Indefinite
Use:
This test is used to determine eligibility for anti-HER2/Neu therapies in gastric and gastroesophageal (GE) junction tumors.
Methodology:
Immunohistochemistry
Reported:
Immunohistochemistry is reported within 7 days. If Gastric HER2/Neu FISH is requested, the report will be provided within 9 days.
Reference Values:
In Notes below
Performed:
Weekly
Interpretation Data:
Surgical Specimens (Resections): A score of 0 is no reactivity or membranous reactivity (staining) in or = 10% of invasive tumor cells.
Biopsy Specimens: A score of 0 is no reactivity or no membranous reactivity (staining) in less than 5 clustered tumor cells. A score of 1+ is tumor cell clusters (greater than or equal to 5 cells) with a faint/barely perceptible membranous reactivity (staining) regardless of percentage of invasive tumor cells stained. A score of 2+ is tumor cell clusters (greater than or equal to 5 cells) with a weak-to-moderate complete, basolateral or lateral membranous reactivity (staining) regardless of percentage of invasive tumor cells stained. A score of 3+ is tumor cell clusters (greater than or equal to 5 cells) with a strong complete, basolateral or lateral membranous reactivity (staining) regardless of percentage of invasive tumor cells stained.