Women with breast cancer in the past can have an increased risk of ovarian cancer in the future. Which of the following statements is true?

• A. By the age of 70, 100% of women with a BRCA1 or BRCA2 mutation will develop ovarian cancer.
• B. By the age of 70, 100% of women with a BRCA1 or BRCA2 mutation will not develop ovarian cancer.
• C. By the age of 70, 30% of women who have a BRCA1 or BRCA2 mutation will develop ovarian cancer.
• D. None of the above.

Answer: (C)