We also talk to these women about the potential role of tamoxifen, which works by blocking estrogen receptors in women with hormone-positive breast cancer, to reduce their risk of breast cancer. There have been some papers that suggest it's also beneficial in mutation carriers. But there have been a lot of questions about whether it's as beneficial in BRCA1 carriers as it is in BRCA2 carriers, because tamoxifen works by blocking estrogen receptors, and three-quarters of the cancers that are diagnosed in BRCA1 carriers are estrogen-receptor negative. With BRCA2 mutations, about 75 percent of cancers are estrogen-receptor positive.
However, people don't like to take drugs when they are healthy. One of the side effects with tamoxifen can be an increased risk of uterine cancer. The uterine cancer risk is less than 1 percent. But if you've already got a fear of cancer because you're at such high risk, that's a scary thing.
What kind of screening is recommended to women with BRCA1 and 2?
The current screening recommendation for mutation carriers is annual mammography starting somewhere between 25 and 35 and clinical examination of the breasts every six to 12 months. Breast self-examination has been recommended by some people, although that the effectiveness of this screening tool is controversial. The only difference between these recommendations and those for the average woman is that you might do the mammograms more often; yearly instead of every two years and you certainly would start at a younger age.
