Breast cancer is one of the most common cancers in the UK. It affects 1 in 8 women (around 13%) and 1 in 870 men (around 1%) during their lifetime. Ovarian cancer is less common. 1 in 52 women (around 2%) will be diagnosed with ovarian cancer during their lifetime. Many people have someone in their family who is affected by one of these cancers. Only a small number of cases are clearly linked to inherited cancer genes.