Detection of Her-2 Neu Gene Expression in Cytological Specimen.
Soheila Korourian, Lillian L Lafond-Shank, Ziyan Salih, Juia Priest, William Bellamy. University of Arkansas for Medical Sciences, Little Rock
Background: Documenting her 2 neu gene copies by fluorescence in situ hybridization has become standard practice for all invasive breast cancers. Identifying the presence of increased her 2 neu gene copy number can greatly impact the type of treatment and ultimate prognosis in breast cancer patients. Such studies are usually conducted on the original core biopsy or excisional biopsy of the primary breast cancer; however, on occasion patients present with metastatic tumors in which case the diagnosis is usually rendered on a cytological specimen. The current study was designed to assess whether these samples can yield adequate and accurate results.
Design: The UAMS Molecular Pathology Laboratory database was searched to identify all cytology specimens submitted for fluoresce in situ hybridization (FISH) for her 2 neu. The cases were stratified according to their source, primary site or metastatic lesions to solid organs, i.e. liver, bone, or effusions. The result were analyzed and compared to paired histological sections of the core biopsies and excisions whenever possible.
Results: From January 2003 to March 2010, our laboratory performed FISH for her 2 neu on 64 cell blocks from cytological specimens including, 10 fine needle biopsies (FNA) obtained from the primary tumor site and 54 FNAs from metastatic sites, including pleural and peritoneal effusions. Five cases were rejected due to low cell number while 1 case failed to return a result due to a technical issue. The test was successfully completed in the remaining 59 cases. A total of 35 cases were from FNA of various metastatic sites including lymph nodes (5) liver (8), lung (4) soft tissue (5), neck masses (3), and brain mass (1), and bone aspirates (9). Ten cases were reported as amplified, two cases were borderline and the remaining cases were negative. Our laboratory also performed FISH on 19 effusions, including 17 pleural effusions, one ascites, and one pericardial effusion. Over the same time period, our laboratory also completed FISH studies on 1313 histological sections of core biopsies or excisions. Of these, 200 (15.8%) cases were reported as positive, 19 cases (1.5%) borderline and 1043 cases negative while 52 cases (4%) were reported as inadequate due to insufficient number of cancer cells, or due to technical difficulty, most likely secondary to problems related to fixation.
Conclusions: Fluorescense in situ hybridization can be performed successfully on cytological specimens. The rate of insufficiency is slightly higher 7.7 as comparison to 4% seen from histological sections.
Wednesday, March 2, 2011 1:00 PM
Poster Session VI # 90, Wednesday Afternoon