A couple months ago, my oncology nurse practitioner, Tara, tells me to pick a date that I can remember.
“Because for five years, I’m going to be asking you what date you started Tamoxifen,” she explains.
It turns out that my breast cancer loves estrogen. The lab report at the beginning of this journey called my tumor “estrogen +++.” This means that the cancer cells grow more quickly in the presence of estrogen. The female hormone is like candy to the cancer cells. This is the case with 80 percent of breast cancers.Tamoxifen takes the candy away by interfering with the activity of estrogen in pre-menopausal women. (Those who get breast cancer after menopause take drugs called “aromatase inhibitors” that block the production of estrogen in the first place.) Tamoxifen allows the estrogen to be made, but blocks breast cells from using the hormone by jamming the estrogen receptors in my breasts. Hopefully, it will help prevent a recurrence in my left breast. It may also help prevent any cancer developing in my right breast. Two studies have confirmed that it’s beneficial for breast cancer survivors to take tamoxifen daily for five years.
While tamoxifen blocks estrogen in my breasts, it strangely acts just like estrogen in other tissues. So it may have some of the same benefits as hormone replacement therapy, like reducing the risk of osteoporosis. But, like all things medical, the drug has a flip side: While it doesn’t cause menopause, it can produce menopausal symptoms like hot flashes, joint pain, headaches, fatigue, vaginal dryness. In 1 or 2 out of 1,000 women, it may cause uterine cancers. It may also cause blood clots, cataracts, and strokes. Oh joy!
The docs are pretty insistent that the benefits of tamoxifen outweigh the risks, so I pick July 4 as my start date. In addition to dropping the kid at horse camp, having a brunch “date” with husband and dogs, walking the dogs on Stinson Beach, hearing my daughter gush about the joys of her first day of horse camp, and eating dinner to the pop-pop-zing of illegal fireworks in the fog, this July 4 marks my Independence from Breast Cancer Day. I hope.