title: TMPRSS2-ERG gene fusion is rare compared to PTEN deletions in stage T1a prostate cancer.
abstract: T1a prostate cancers (cancer found incidentally in transurethral resection, <5% of the tissue) are indolent tumors of the transition zone. The overexpression of ERG and the inactivation of PTEN have been shown to be important drivers of carcinogenesis in large series of prostate cancer, but the genetics of transition zone tumors have not been well characterized. We evaluated the status of ERG and PTEN in formalin-fixed paraffin-embedded tissue using immunohistochemical and FISH analysis in 54 T1a transition zone tumors. The protein expression of ERG was determined using a rabbit monoclonal antibody and nuclear staining was scored as positive or negative. The genomic status of ERG was determined using three colored FISH using an ERG-TMPRSS2 tri-color probe set. The protein expression of PTEN was determined using a rabbit monoclonal antibody and cytoplasmic, and nuclear staining was scored as positive or negative. The genomic status of PTEN was determined using dual color FISH with a PTEN probe and a CEP10 probe. We found ERG rearrangement in 2 of 54 tumors (4%), one with protein overexpression by immunohistochemistry. PTEN inactivation was seen in 13 of 54 tumors (24%). Nine of the 13 PTEN alleles were inactivated by hemizygous deletion. No homozygous PTEN deletion was observed. PTEN deletion and ERG rearrangement were mutually exclusive. ERG rearrangement was rare compared to peripheral zone tumors and to PTEN inactivation in T1a transition zone tumors. © 2016 Wiley Periodicals, Inc.
authors: Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana.
authors: Kurt W
authors: KW
authors: Fisher
authors: Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana.
authors: Shaobo
authors: S
authors: Zhang
authors: Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana.
authors: Mingsheng
authors: M
authors: Wang
authors: Department of Urology, Institute of Pathological Anatomy and Histopathology, Polytechnic University of the Marche Region (Ancona), United Hospitals, Ancona, Italy.
authors: Rodolfo
authors: R
authors: Montironi
authors: Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, Michigan.
authors: Lisha
authors: L
authors: Wang
authors: Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana.
authors: Lee A
authors: LA
authors: Baldrige
authors: Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana.
authors: Jonas Y
authors: JY
authors: Wang
authors: Departments of Pathology and Laboratory Medicine, Case Western Reserve University, Cleveland, Ohio.
authors: Gregory T
authors: GT
authors: MacLennan
authors: Department of Pathology and Laboratory Medicine, Henry Ford Health System, Detroit, Michigan.|Josephine Ford Cancer Institute, Henry Ford Health System, Detroit, Michigan.|Department of Pathology, Wayne State University School of Medicine, Detroit, Michigan.
authors: Sean R
authors: SR
authors: Williamson
authors: Faculty of Medicine, Department of Pathology and Surgery, Cordoba University Spain and Champalimaud Clinical Center, Cordoba University, Lisbon, Portugal.
authors: Antonio
authors: A
authors: Lopez-Beltran
authors: Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana.
authors: Liang
authors: L
authors: Cheng
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017353:Gene Deletion; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D015514:Oncogene Proteins, Fusion / Q000235:genetics* / Q000378:metabolism; D051059:PTEN Phosphohydrolase / Q000235:genetics* / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*
chemical_list: D015514:Oncogene Proteins, Fusion; C515553:TMPRSS2-ERG fusion protein, human; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human
keywords: PTEN loss; T1a; TMPRSS2-ERG rearrangement; fluorescence in situ hybridization; insignificant cancer; prostate; transition zone