title: Urinary protein biomarkers of cancer.
abstract: BACKGROUND
  Although several cancer biomarkers are now in use, few have the necessary sensitivity and specificity to eliminate the need for invasive diagnostic procedures. With the expansion of proteomics, new technologies have been used to study various cancers, resulting in the discovery of several potential urine biomarkers. Urine is an ideal medium for the detection of biomarkers because of the non-invasive means of collecting samples and demonstrated shedding of cells, proteins, enzymes, nucleic acids and metabolic products into urine during various pathological processes.
  
  
  OBJECTIVE
  To review the contemporary literature regarding urinary protein markers of cancer.
  
  
  METHODS
  A PubMed search for 'urinary protein biomarkers of cancer' revealed 4679 scientific publications. The search was limited to studies published over the last 5 years and reviewed pertinent findings regarding biomarker evaluation and discovery.
  
  
  RESULTS
  Several urinary protein biomarkers have been described for urologic, gynecologic, gastrointestinal and neurologic tumors. Some have been selected for use in clinical practice, whereas others have been abandoned owing to inconclusive follow-up studies.
  
  
  CONCLUSIONS
  Several potential urinary protein markers for cancer exist, yet multi-institutional, prospective trials are needed to validate results before implementation in clinical scenarios.
authors.affiliation: Post-Doctoral Fellow James Buchanan Brady Urological Institute, Marburg 110, 600 N Wolfe Street, Baltimore, MD 21287, USA.
authors.forename: Brian Keith
authors.initials: BK
authors.lastname: McNeil
authors.forename: Robert H
authors.initials: RH
authors.lastname: Getzenberg