Because my cancer was hormone-sensitive, I need to take a drug called Tamoxifen that is proven to reduce the risk of the cancer returning and possibly spreading to another part of my body. The newest recommendation is to stay on this drug for 10 years. Great news, right? A drug that could actually help keep me alive. I am lucky to have that option. Unfortunately, hormonal therapy for cancer comes with a whack of side effects. The biggest one for me is that I've been told not to get pregnant while taking it, due to its potential to cause birth defects.