The discovery of five new genes associated with breast cancer and 13 new mutational signatures that influence tumour development will help clinicians develop more personalised options for treating the disease.
Researchers from the International Cancer Genome Consortium Breast Cancer Working Group at the UQ Centre for Clinical Research (UQCCR) contributed to the project, the largest-ever global breast cancer genome sequencing study.
The results, published in Nature and Nature Communications,reveal where some cellular processes go wrong and how this stimulates cancer formation.
UQCCR’s Professor Sunil Lakhani said the analysis of 560 genomes to learn why breast cancer develops the way it does will improve how patients receive treatment.
“We now understand that while the mutations of BRCA1 and BRCA2 genes are known to increase the predisposition to breast cancer, the DNA mutation patterns are distinct indictaing that the way they cause breast cancer is quite different,” Professor Lakhani said.
“Knowing what genetic variations exist in breast cancer and exactly where they occur in the genome will help us better classify familial breast cancer patients and work out the most appropriate treatment for each person.”
Dr Peter Simpson, also from UQCCR’s International Cancer Genome Consortium Working Group, said looking closely at the DNA’s repair machinery and the mutation processes that occur in cancer will help researchers identify the defective cellular processes that cause the cancer to start in the first place.
“Our DNA is constantly adapting in response to damage by environmental factors or simply from wear and tear in the cell. The patterns of these mutations, their mutational signatures, give us clues about what causes a cancer.
“Now we’ll be able to understand what influences breast cancer, just like we now understand how lung cancers are linked to cigarette smoking and skin cancers are linked to excessive exposure to UV sunlight,” said Dr Simpson.
The international study was led by Professor Sir Michael Stratton from the Wellcome Trust Sanger Institute in the UK and involved breast cancer patients from around the world, including Australia, the USA, Europe and Asia.
The Queensland-based institutions involved in the study include Pathology Queensland, QIMR Berghofer, and the Royal Brisbane Women’s Hospital’s Breast Unit.
The Brisbane Breast Bank, set up ten years ago and now housed at the UQCCR, played a pivotal role in supplying breast cancer tissue for analysis from consenting patients.