title: Mitochondrial genome analysis in biofluids for early cancer detection and monitoring.
abstract: BACKGROUND
  Biofluids collected in a non-invasive fashion are potentially valuable samples for assaying genomic alterations for early detection and monitoring of cancer. The low cellularity and nucleic acid content in biofluids, the high copy number of the mitochondrial genome (mtgenome) and its noted early imprints in cancer make this molecule theoretically more sensitive than nuclear targets to measure for early cancer detection.
  
  
  OBJECTIVE
  This review explores mtgenome analysis in biofluids and addresses the question of whether targeting the mtgenome in biofluids is superior or equivalent to analysis of nuclear genomic alterations.
  
  
  METHODS
  The literature was retrieved from PubMed using a combination of the following keywords: mtDNA, mutation, deletion, content, copy number, cancer, biofluids, bodily fluids and the specific cancers described here. Studies that analyzed mtgenome alterations in biofluids were included. Analytical methods available for assaying mtgenome changes in biofluids are discussed.
  
  
  RESULTS
  Despite the limited data available, mtgenome changes in biofluids have been demonstrated in a wide variety of cancer patients.
  
  
  CONCLUSIONS
  Mtgenome analysis in biofluids is feasible and relatively easy. Despite the paucity of data, tumor-specific mtgenome changes are observed in biofluids of cancer patients. Given the multiple copies per cell of the mtgenome, future cancer detection efforts should consider complementary analysis of mtgenome changes in biofluids.
authors.affiliation: Senior Scientist Genesis Genomics, Inc., 290 Munro Street, Ste 1000, Thunder Bay, Ontario, P7A 7T1, Canada +1 807 768 4516 ; +1 807 346 8105 ; gabriel.dakubo@genesisgenomics.com.
authors.forename: Gabriel D
authors.initials: GD
authors.lastname: Dakubo