Angelina Jolie has undergone an operation to remove her ovaries and fallopian tubes.
The actress has written about her decision in an article for the New York Times, entitled Diary of a Surgery.
Angelina carries a mutation in the BRCA1 gene that gave her an 87 per cent risk of breast cancer and a 50 per cent risk of ovarian cancer.
Angelina's mother died in 2007, aged 56, after a long battle with cancer.
Two years ago she underwent a preventive double mastectomy and has now undergone preventive surgery again after a check up two weeks ago revealed "a number" of elevated inflammatory markers that could be a sign of early cancer.
"I went through what I imagine thousands of other women have felt," Angelina explained. "I told myself to stay calm, to be strong, and that I had no reason to think I wouldn't live to see my children grow up and to meet my grandchildren.
"I called my husband [Brad Pitt] in France, who was on a plane within hours. The beautiful thing about such moments in life is that there is so much clarity. You know what you live for and what matters. It is polarising, and it is peaceful."
Angelina explained that she chose to have the procedure on the advice of her doctors.
"In my case, the Eastern and Western doctors I met agreed that surgery to remove my tubes and ovaries was the best option, because on top of the BRCA gene, three women in my family have died from cancer," she said. "My doctors indicated I should have preventive surgery about a decade before the earliest onset of cancer in my female relatives. My mother's ovarian cancer was diagnosed when she was 49. I'm 39.
"Last week, I had the procedure: a laparoscopic bilateral salpingo-oophorectomy. There was a small benign tumor on one ovary, but no signs of cancer in any of the tissues."
She continued, "I am now in menopause. I will not be able to have any more children, and I expect some physical changes.
"But I feel at ease with whatever will come, not because I am strong but because this is a part of life. It is nothing to be feared. I know my children will never have to say, 'Mom died of ovarian cancer'.
"It is not easy to make these decisions. But it is possible to take control and tackle head-on any health issue."