One option for preserving your fertility is to harvest mature eggs from your ovaries before you start breast cancer treatment. Without fertility drugs, only one or two eggs, at most, per cycle will be harvested. With fertility drugs, as many as eight to ten mature eggs can be released and harvested. But using fertility drugs greatly increases the amount of estrogen in the body and that may stimulate the growth of hormone-receptor-positive breast cancer cells.
Research does suggest that stimulating the ovaries with fertility drugs can increase the risk of ovarian cancer. But it's important to know that overall, this risk is still very low.
To minimize any risk, most doctors that specialize in fertility for cancer patients develop a customized egg-stimulating regimen for each woman. In many cases, the regimen includes tamoxifen or an aromatase inhibitor — alone or together with traditional fertility drugs — to both stimulate the ovaries and protect the body from high estrogen levels.
When tamoxifen or aromatase inhibitors are used in this way, they are given at high doses for just a few days (about 10 to 12 days). This is very different from how they're used in breast cancer treatment — at low doses, over a long period of time.
To harvest the eggs, you wait for your period to start. Then you inject yourself with your personalized egg stimulating regimen for about 10 to 12 days. You'll get regular ultrasounds and blood work to monitor your eggs' growth. Once the eggs are mature, they're removed during a short outpatient surgery (about 20 minutes).
Eggs can then be stored and used to start a pregnancy when you're finished with treatment.