title: [TMPRSS2-ERG gene fusion in metastatic prostate cancers: a study of fine needle aspiration specimens].
abstract: OBJECTIVE
  To investigate diagnostic values of the detection of TMPRSS2-ERG gene fusion in metastatic prostate cancer.
  
  
  METHODS
  A total of 32 fine needle aspiration (FNA) specimens of metastatic prostate carcinomas were retrieved from the pathology files at MD Anderson Cancer Center. The metastatic sites included the pelvic and remote lymph nodes, liver, bone, and thyroid gland. Immunohistochemical staining for PSA, PAP, synaptophysin, chromogranin A was performed. TMPRSS2-ERG gene fusion was evaluated on sections of cell blocks by fluorescence in situ hybridization (FISH) using ERG gene break-apart probes.
  
  
  RESULTS
  The mean age of the patients was 67 years. Twenty-six patients had a previous history of prostatic adenocarcinoma, while 6 patients presented initially with metastasis. In 11 patients, the metastatic lesions showed characteristic features of small cell carcinoma (SCC) and were positive for synaptophysin (9/9), chromogranin A (7/8), but negative for prostatic specific antigen (7/7). FISH analysis demonstrated a rearrangement of ERG gene in 10 of 32 cases (31.3%), and the rearrangement was associated with deletion of the 5' ERG gene in 6 cases. In addition, the copy number of ERG rearrangement gene locus was increased in 8 cases. Among the 11 cases with SCC features, a rearrangement of ERG gene was present in 5 cases, of which a deletion of the 5' ERG gene and increased copy number were seen in 3 cases.
  
  
  CONCLUSIONS
  TMPRSS2-ERG gene fusion can be evaluated in FNA specimens of metastatic prostate cancer. Metastatic prostate cancers have a high prevalence of TMPRSS2-ERG gene fusion along with a frequent copy number increase of ERG gene. TMPRSS2-ERG gene fusion persists in metastatic prostate cancers and even in those with poorly differentiated SCC features. Therefore, an identification of the TMPRSS2-ERG gene fusion may be used to establish the prostatic origin of metastasis.
authors.affiliation: Department of Pathology, Huadong Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Li
authors.initials: L
authors.lastname: Xiao
authors.forename: Xiong-zeng
authors.initials: XZ
authors.lastname: Zhu
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Yun
authors.initials: Y
authors.lastname: Gong
authors.forename: C Charles
authors.initials: CC
authors.lastname: Guo
mesh_terms: D000135:Acid Phosphatase; D000230:Adenocarcinoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000556:secondary / Q000601:surgery; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D018288:Carcinoma, Small Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000556:secondary / Q000601:surgery; D053379:Chromogranin A / Q000378:metabolism; D005500:Follow-Up Studies; D050939:Gene Fusion; D015321:Gene Rearrangement; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion / Q000235:genetics* / Q000378:metabolism; D017430:Prostate-Specific Antigen / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism; D016708:Synaptophysin / Q000378:metabolism
chemical_list: D053379:Chromogranin A; D015514:Oncogene Proteins, Fusion; D016708:Synaptophysin; C515553:TMPRSS2-ERG fusion protein, human; D000135:Acid Phosphatase; C428439:prostatic acid phosphatase; D017027:Protein Tyrosine Phosphatases; D017430:Prostate-Specific Antigen