Even in the precancerous stage, called ductal carcinoma in situ (DCIS) when abnormal cells are confined to a milk duct, physicians almost always advise women to have a lumpectomy or mastectomy along with radiation, because about 20% of the 65, 000 cases of DCIS found every year in the U.S. become invasive cancer.

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At present the options to reduce their risks are limited - a double mastectomy or having their ovaries removed.

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In New York, for one, before a surgeon can perform a mastectomy or lumpectomy on a breast cancer patient, that patient must meet with a plastic surgeon to learn her options.

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Prof Gareth Evans, an oncologist at Christie Hospital, says for some of those women, taking tamoxifen could be an alternative to having a preventative mastectomy, or breast removal.

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Jolie's relating her decision to have a preventive mastectomy is no more or less brave than Orenstein's decision not to have one.

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However, authors of the study indicate that a double mastectomy may make sense for women with a strong family history of breast or ovarian cancer, or for women who've tested positive for genetic mutations in the BRCA genes.

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