A mutation in a certain gene linked to an increased risk of breast and ovarian cancer could help with prevention measures, research has found.
A team of researchers led by the Institute of Cancer Research found that mutations in a gene called PPM1D is linked to an increased risk of the two cancers.
Women with PPM1D mutations have a 20% chance of developing breast or ovarian cancer - double the breast cancer risk and more than 10 times the ovarian cancer risk of women in the general population.
However, the discovery could help with genetic testing and prevention in particular for ovarian cancer, which is often diagnosed at an advanced stage.
The study, published in the journal Nature this week, said that PPM1D seems to be working in a completely different way to other genes known to increase the risk of breast and ovarian cancer, such as BRCA1 and BRCA2.
Study leader Professor Nazneen Rahman, head of genetics at the ICR and head of the cancer genetics clinical unit at the Royal Marsden Foundation Trust, said: “This is one of our most interesting and exciting discoveries.
“At every stage the results were different from the accepted theories. We don’t yet know exactly how PPM1D mutations are linked to breast and ovarian cancer, but this finding is stimulating radical new thoughts about the way genes and cancer can be related.
“The results could also be useful in the clinic, particularly for ovarian cancer which is often diagnosed at an advanced stage.
“If a woman knew she carried a PPM1D mutation and had a one in five chance of developing ovarian cancer, she might consider keyhole surgery to remove her ovaries after completing her family.”
The team analysed 507 genes involved in DNA repair in 1,150 women with breast or ovarian cancer, identifying PPM1D gene mutations in five women.
They then sequenced the PPM1D gene in 7,781 women with breast or ovarian cancer and 5,861 people from the general population.
There were 25 faults in the PPM1D gene in women with cancer and only one in the general population, a highly statistically significant difference.
Professor Alan Ashworth, ICR chief executive and one of the study researchers, said: “This discovery really does turn conventional wisdom about the way genetic mutations can lead to cancer on its head.
“As we unravel this puzzle, we are likely to gain valuable insights about how cancer develops, and new tools for assessing people’s risk of the disease and targeting preventive treatment.”
The study was funded by the ICR, the Wellcome Trust, Cancer Research UK and Breakthrough Breast Cancer.