"Breast cancer is not one disease but collection of diseases"

Washington, Dec 24 (ANI): Scientists from Wellcome Trust Sanger Institute have found that breast cancer is not one disease but a collection of several diseases.

They cracked the genetic code of breast cancer and uncovered genomic rearrangements, which involved reshuffling and reorganisation of the genome and include deletions, duplications and novel juxtaposition of DNA sequences.

"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," said Professor Mike Stratton of the Wellcome Trust Sanger Institute.

"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," he added.

During the study, the team used next-generation DNA sequencing to produce maps of genome rearrangements in 24 breast cancer samples, which were chosen to include the major subtypes of breast cancer and also included examples of breast cancers arising in BRCA1 and BRCA2 breast cancer families.

One breast cancer showed just a single genomic rearrangement - while others showed more than 200.

The study provided insights into how the genetic code is disrupted in some cancers and also the way broken bits of DNA are "glued" back together in cancer cells.

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

"At the moment we do not know what the defect is or the abnormal gene underlying it, but we are seeing the result of its malfunction in the hideously untidy state of these genomes. Identifying the underlying mutated cause will be central to working out how some breast cancers develop," Futreal added. (ANI)