HER2 Gene Status in Breast Cancer Metastases
Author Information
Author(s): Tapia Coya, Savic Spasenija, Wagner Urs, Schönegg René, Novotny Hedvika, Grilli Bruno, Herzog Michelle, Barascud Audrey DeVito, Zlobec Inti, Cathomas Gieri, Terracciano Luigi, Feichter Georg, Bubendorf Lukas
Primary Institution: University Department of Pathology of Basel and Baselland
Hypothesis
To compare HER2 status in primary breast cancers and their matched distant metastases.
Conclusion
HER2 gene status is mostly preserved in breast cancer metastases, but discrepancies can occur due to interpretational difficulties and tumor heterogeneity.
Supporting Evidence
- HER2 amplification was found in 20% of distant metastases.
- Discordant HER2 status was observed in 7.6% of patients.
- Re-evaluation increased concordance to 97.1%.
- Interpretational difficulties accounted for discrepancies in 4.7% of cases.
- Three patients had unexplained discrepancies in HER2 status.
- HER2 amplification was significantly associated with nuclear grade.
- Time to metastasis was not significantly associated with pT or pN categories.
- Cytological specimens are suitable for HER2 FISH analysis.
Takeaway
This study looked at how the HER2 gene behaves in breast cancer as it spreads. Most of the time, it stays the same, but sometimes it can change, which can affect treatment.
Methodology
HER2 status was determined using fluorescence in situ hybridization (FISH) on cytological specimens from distant metastases and compared with primary tumors.
Potential Biases
Potential interpretational variability in borderline HER2 results.
Limitations
The study did not have information on treatment between the resection of the primary tumor and the occurrence of distant metastases.
Participant Demographics
{"mean_age":57.5,"age_range":"26-85","tumor_size_distribution":{"less_than_equal_2cm":28,"between_2_and_5cm":57,"greater_than_5cm":9},"histological_types":{"ductal":82,"lobular":12,"ductulo-lobular":10,"medullary":1},"nuclear_grades":{"grade_1":7,"grade_2":41,"grade_3":55}}
Statistical Information
P-Value
0.0639
Confidence Interval
95% CI 0.61 to 0.92
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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