Research shows that breast cancer is 'a family of diseases'

Published on Wednesday 23 December 2009 23:04

BREAST cancer is not one condition but a family of diseases with strikingly different genetic profiles, a new study has shown.

Scientists who carried out a detailed study of DNA from 24 breast tumours were astonished by the extent of the damage they found and its diversity.

Professor Mike Stratton, from the Wellcome Trust Sanger Institute who led the study, said: "We have looked at the level of the DNA sequence at just how splintered and reorganised the genome is in many breast cancers.

"We were, frankly, astounded at the number and complexity of rearrangements in some cancers.

"Just as important, the genomes were different from each other, with multiple distinctive patterns of rearrangement observed, supporting the view that breast cancer is not one, but several diseases."

The findings were reported today in the latest issue of the journal Nature.

"It looks as though some breast cancers have a defect in the machinery that maintains and repairs DNA and this is resulting in large numbers of these abnormalities," said Dr Andy Futreal, also from the Sanger Institute.

"It appears that in different subtypes of breast cancers, distinct mechanisms of DNA repair are impaired, leading to different types of genomic disorganisation," said Dr Jorge Reis-Filho, from the Breakthrough Breast Cancer Research Centre at the Institute of Cancer Research.

"If we damage further an already-faulty DNA repair system using tailored therapies, one can kill tumour cells selectively, without harming normal cells.

"There are some interesting results suggesting that breast cancers with defects in DNA repair are more sensitive to drugs that cause additional DNA damage."