TMPRSS2-ERG融合基因在转移性前列腺癌中的表达

目的 检测转移性前列腺癌中TMPRSS2-ERG基因融合的发生率,探讨ERG基因重排在前列腺癌进展中的作用.方法 收集32例由细针穿刺诊断的转移性前列腺癌,穿刺部位包括盆腔及远处淋巴结、肝、骨、甲状腺等,回顾相关临床病理学资料.免疫组织化学采用EnVision法标记前列腺特异性抗原、突触素和嗜铬粒素A.运用ERG分离断...

TMPRSS2-ERG gene fusion in metastatic prostate cancers: a study of fine needle aspiration specimens

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.