Scientists at NUI Galway have made an important development in the genetics of breast cancer, identifying traits that are associated with long term survival.
The research at NUIG analysed the genomes of ‘luminal’ breast cancer patients, the most common varieties, to look for associations with long term survival rates.
Carried out by Lydia King during her studies in NUI Galway’s MSc in Biomedical Genomics programme, the research has been published in the international journal PLOS ONE.
Patients with ‘luminal’ type breast cancers now have survival rates of over 80% five years after treatment when there has been successful early detection and treatment.
However, measuring long term survival is less well understood, as studies have shown that more than half of recurrences for luminal breast cancers take place after this time point.
Genomes are the collection of all DNA in the chromosomes of cells containing all of our inherited genetic information.
Cancer is often described as a disease of the genome, as it results from a breakdown of the DNA instructions in our cells, causing them to proliferate out of control.
These alterations are a hallmark of a tumour, and can vary wildly in the severity of the damage they do to a person’s DNA. The level of alterations in the genome of a cancer cell is known as ‘genome instability’.
The NUIG team focused on whether an overall measurement of genome instability in cancer cells from luminal breast cancer patients, observed at diagnosis and before treatment started, could provide additional information in predicting their long-term survival.
To test this hypothesis, they analysed data from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) led by Cambridge University.
The METABRIC gathered biopsies taken from over 2000 patients suffering from primary breast carcinoma enrolled between 1977 and 2005, making it a very powerful resource for high quality genetic data for those researching breast cancer.
Looking at this data allowed Lydia and her team to confirm the significantly worse prognoses for luminal A patients suffering from the most extreme levels of genome instability in their tumour biopsies.
“This is an excellent example of how interdisciplinary research is supposed to work in the genomics data sciences,” said Dr Aaron Golden, physicist and senior author of the paper.
The project started as a “speculative idea” between himself, biochemist Dr Andrew Flaus, and Lydia King.
“We then received the invaluable assistance of our statistician colleague Dr Emma Holian and through Lydia’s phenomenally hard work we could demonstrate the promise of precision genomics in cancer treatment.”
Using the data gathered, they were able classify patients by their risk levels using genomic instability analysis.
It is suggested that incorporating genomic instability analysis into patient care could help improve diagnoses and allow oncologists to tailor treatments for individual patients.