Analysis of gene alterations of mitochondrial DNA D-loop regions to determine breast cancer clonality

Br J Cancer. 2012 Dec 4;107(12):2016-23. doi: 10.1038/bjc.2012.505. Epub 2012 Nov 20.


Background: It has been a challenge to determine breast cancer clonality accurately. The aim of the present study was to assess methods using formalin-fixed paraffin-embedded (FFPE) tissue to differentiate new primary tumours from true recurrences that are associated with poorer prognoses and often require more aggressive treatment.

Methods: We investigated the novel method of analysing gene alterations of mitochondrial DNA D-loop region (GAMDDL) and compared it with the conventional method of analysing the X-chromosome-linked human androgen receptor (HUMARA). The FFPE sections of primary and secondary breast cancers, the non-neoplastic mammary gland, and lymph nodes were examined.

Results: Informative rates for HUMARA, GAMDDL, and combined analyses were 42.1%, 76.9%, and 89.5%, respectively. All of the 10 contralateral breast cancers were determined to be non-clonal. In contrast, 3 out of 8 (37.5%) of the ipsilateral secondary tumours shared a clonal origin with the primary tumour and were classified as true recurrences, whereas 4 out of 8 (50%) were classified as new primary tumours.

Conclusion: GAMDDL analysis represents a novel and useful molecular method for examining the precise cell lineages of primary and secondary tumours, and was more accurate than HUMARA in determining clonality.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Breast Neoplasms / diagnosis*
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / pathology
  • Chromosomes, Human, X
  • Clone Cells* / pathology
  • DNA, Mitochondrial / genetics*
  • Female
  • Formaldehyde
  • Humans
  • Laser Capture Microdissection
  • Lymph Nodes / pathology
  • Mammary Glands, Human / pathology
  • Middle Aged
  • Mutation*
  • Neoplasm Recurrence, Local / diagnosis*
  • Neoplasm Recurrence, Local / genetics
  • Neoplasms, Second Primary / diagnosis*
  • Neoplasms, Second Primary / genetics
  • Paraffin Embedding
  • Polymerase Chain Reaction
  • Receptors, Androgen / genetics


  • AR protein, human
  • DNA, Mitochondrial
  • Receptors, Androgen
  • Formaldehyde