Research has found out that women diagnosed with breast cancer have an identical twin. Previous research, from the charity Cancer Research, suggests that, before the menopause, if one identical twin has breast cancer, their sister has a much increased risk of also getting the disease. Now researchers at the University of Southern California show that the risk persists after the menopause.
They studied 1,202 pairs of identical and non-identical twins. They found that women who have an identical twin sister with breast cancer run a four times increased risk of developing the disease. This is a far higher risk than had been expected. What's more - the onset of breast cancer is much earlier than average. An identical twin is likely to develop the disease within five years of her sister. This suggests it could be well worthwhile asking a woman newly diagnosed whether she has a twin - who could benefit from screening and close monitoring to help her deal with her increased risk