Is the amount of tissue provided by fine-needle biopsy enough 2 determine her2status?

This may be of interest to urge oncologists to try to needle metastases in her2 negative patients to see if their mets are her2 positive (they are reluctant to do big surgeries if patient already has lots of involvement)

It should also help keep the surgeries performed to diagnose and characterize breast cancer to a minimum which should be important as something about the inflammatory cycle set off by surgery (smaller surgery, less inflammation set off) is felt to worsen the situation or encourage metastasis...

But, as always a warning, sensitivity and specificity are not 100% (THEY NEVER ARE) , that is it won't catch every single one accurately and there are cases where it will be wrong in the other direction --false positives

Also, not everyone is doing CISH (different than FISH as it uses chromogenicity instead of fluorescence when looking for the her2neu)

Here it is:
1: Oncol Rep. 2006 Apr;15(4):803-8. Links

Detection of human epidermal growth factor receptor 2 protein and gene in fine needle aspiration cytology specimens and tissue sections from invasive breast cancer: Can cytology specimens take the place of tissue sections?

Sumiyoshi K, Shibayama Y, Akashi S, Nohara T, Iwamoto M, Kobayashi T, Nishimura H, Yoshinaka R, Harada T, Tanigawa N.

Departments of Pathology and General and Gastroenterological Surgery, Osaka Medical College, Osaka, Japan.

Overexpression of HER2 protein and HER2 gene amplification in breast cancer are prognostic factors for the response to specific medical treatments such as trastuzumab, endocrine therapy, and chemotherapy. Whereas HER2 expression and gene amplification are generally examined in tissue sections, we investigated whether specimens from fine needle aspiration cytology (FNAC) are adequate for these analyses. HER2 protein overexpression and HER2 gene amplification were assessed in both FNAC specimens and tissue sections from 58 cases of invasive breast cancer. Immunohistochemistry assay for HER2 protein expression was performed according to the HercepTest protocol, and HER2 gene amplification was examined with the Spot-light CISH (chromogenic in situ hybridization) Detection kit. There was a significant positive correlation between assessments of HER2 protein status in the cytology specimens and tissue sections. The sensitivity, specificity, and accuracy of HER2 gene amplification detection in cytology specimens in relation to those in tissue sections were 84.0% (21/25 cases), 87.9% (29/33 cases), and 86.2% (50/58 cases), respectively. FNAC specimens are suitable for detection of HER2 overexpression and HER2 gene amplification in invasive breast cancer.

PMID: 16525662 [PubMed - in process]