The benefit of increased screening in women with hereditary cancer syndromes is best established for breast cancer. More frequent screening with mammography and the addition of breast magnetic resonance imaging (MRI) does detect earlier cancers in women at high risk of breast cancer.6 The benefit of early detection also translates into improved survival for these women.7 In contrast, screening for ovarian cancer with ultrasound and CA-125 has never been shown to improve early detection or survival.8,9 The same is true for endometrial cancer, but screening can be performed at the discretion of the physician following National Comprehensive Cancer Network (NCCN) guidelines for women who have not yet undergone risk-reducing surgery.
For women with a genetic predisposition to breast cancer, screening begins from age 20 to 25 typically with MRI (mammograms are omitted prior to age 30 in women with BRCA mutations), with slight variation based on the specific gene3 (Table 4). MRI is often used in younger women to reduce lifetime radiation exposure and idiopathic cancers. There are no recommendations for more intensive MRI screening after age 75, and its use should be individualized.3
Despite lack of evidence for ovarian cancer screening, in women who have not yet undergone oophorectomy and are at high-risk the NCCN recommends consideration of annual transvaginal ultrasound (TVUS) and CA-125.3 Women should be counseled regarding the extreme limitations of current ovarian cancer screening. Likewise, screening with TVUS and endometrial biopsy every 1 to 2 years can be considered for patients at high risk of uterine cancer, although data supporting this recommendation are limited and many simply recommend prompt evaluation of any irregular bleeding.3
Even before women are ready to undergo a risk-reducing surgery, there are ways they can reduce their cancer risk through the use of medications, primarily birth control pills for ovarian cancer risk reduction and selective estrogen-receptor modulators (SERMs) for breast cancer risk reduction. As long-acting reversible contraception is gaining in popularity, it is important to remember that women with a genetic predisposition to ovarian cancer should consider combined oral contraceptives (OCs). Any use of them has been shown to decrease risk of ovarian cancer in women with BRCA1 and 2 mutations by 50%, with degree of benefit increasing by duration of use.10
A common concern is the impact of this strategy on the patient’s risk of breast cancer. Evidence has varied, from there being no increased risk to only slightly increased risk of breast cancer with OC use in these women.11,12 The benefit in ovarian cancer reduction may outweigh this risk, as more successful screening and treatment strategies exist for breast cancer.
SERMs such as tamoxifen and raloxifene are medical options for reducing breast cancer risk for women with hereditary breast and ovarian cancer syndrome, both in the setting of reducing a contralateral breast cancer by 45% to 60% and reducing risk of a first breast cancer by 62%.13,14 Some evidence suggests the benefit may be greatest in BRCA2 carriers compared to BRCA1, as these cancers are more likely to be hormone receptor-positive.13