A new genomics study has found that men are three times more likely to die from prostate cancer if they possess mutations the retinoblastoma 1 (RB1) gene. The researchers also found that men with the mutation were seven times more likely to relapse than men without the mutation. According to Medical News - the study, which was published in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS) on May 2019, is the largest of its kind. The study “really got under the bonnet of prostate cancer to understand the ‘engine’ driving tumour growth and explore how a wide range of genes affect the disease and its response to treatment” said Professor Johann de Bono, one of the authors of the study.
“We identified one particular genetic mutation that seems to indicate that tumours are going to be very aggressive and that the affected men need the most intensive treatment we have available.”
“Our research could also open up various new approaches to prostate cancer treatment and offers the intriguing suggestion that some patients could benefit from immunotherapy alongside an existing breast cancer drug,” de Bono explained.
‘RB1 had the strongest association with poor outcome’
The retinoblastoma gene, also called the RB1 gene, is responsible for making a protein called retinoblastoma protein (pRB). The retinoblastoma protein is a tumour suppressor, which means it regulates cell growth and inhibits a cell’s ability to divide too quickly or too often. Other functions pRB include interacting with other proteins to influence the survival of cells, as well as apoptosis (organized cell death), and differentiation (the process of maturation from a stem cell to a mature, functional cell in the body). A number of cancers have been associated with genetic changes (mutations) in the RB1 gene. Retinoblastoma, a rare type of eye cancer often seen in early childhood, bladder cancer, lung cancer, and in some cases skin and bone cancer are just some of the conditions associated with mutations in the RB1 gene.
The discoveries made by this study suggest that clinical trials with a CDK4/6 inhibitor, which is used in certain breast cancer treatments, may be effective in prostate cancer when used in combination with immunotherapy.
The study concludes that RB1, in particular, is the molecular factor linked to the poorest clinical outcomes, and stresses that more research needs to be done into the resistance to therapy caused by the loss of the retinoblastoma protein and into new therapies that can target this loss.
-205x205.jpg)
