Ovarian tissue freezing
Freezing ovarian tissue is still considered experimental, but guidelines from the American Society of Clinical Oncology say new and upcoming evidence may change that in the near future.
How can this delay my treatment? In this experimental procedure, ovarian tissue is removed in a single operation and should not significantly interfere with starting treatment. The tissue should be removed before starting chemotherapy. Depending on your treatment plan and the availability of your fertility specialist, some treatment may be delayed to complete the operation before you begin chemotherapy.
How much will this cost? Ovarian tissue freezing is an experimental procedure so the cost can vary significantly based on the study site. Because it is experimental, insurance may not cover the costs associated with this option. In the future, it may be possible to grow eggs from the tissue or it may be possible to transfer the tissue back to your body. Both of those options will have additional costs and both are considered experimental at this time.
Can this interact with my hormone receptor-positive breast cancer? Ovarian tissue freezing does not require hormones to stimulate egg production and will not affect hormone receptor-positive breast cancer.
Your doctor will likely recommend taking hormonal therapy for 5 to 10 years. If you have the frozen ovarian tissue transplanted back to your body, it may cause your hormone status to change and that can affect which hormonal therapy you are given. If you are interested in trying to get pregnant at the time of your tissue transplantation, you must first speak with your doctor about safely taking a break from hormonal therapy while you attempt pregnancy.
Does my age impact this? Yes. Because women are born with all the eggs they will ever have, age impacts both the quantity and quality of eggs in women. This is an experimental procedure and centers should have strict age guidelines on who can enroll in this process.
Do I need a partner or sperm donor? No. Ovarian tissue is frozen with immature eggs present. In the future, if this tissue is transplanted, the goal would be that eggs from that tissue would mature inside the body, ovulate or release from the ovary, and potentially result in pregnancy after sexual intercourse. Studies are ongoing to determine the effectiveness of this as well as attempting to grow eggs from the tissue directly outside the body. Both options are considered experimental.
Some women are diagnosed with breast cancer before they’ve finished having children or even had the chance to start a family. Certain treatments can increase your risk of infertility, so it’s important to consider this before starting treatment.
Some types of breast cancer treatment can lead to medical menopause, meaning that your periods stop and your ovaries no longer produce eggs. Medical menopause is sometimes temporary, lasting only during treatment and for a few months afterward, but it can be permanent. The risk of permanent menopause is greatest for women in their mid-30s and older.
If you’re premenopausal and diagnosed with hormone receptor-positive breast cancer, your doctor will likely recommend the estrogen-blocking medicine tamoxifen for 5 to 10 years after initial treatment ends. Although tamoxifen doesn’t put you into menopause, you shouldn’t get pregnant while taking it because it can harm a developing fetus. Depending on your age, you might be concerned about waiting several years to attempt pregnancy.
If you think you might want biological children in the future, you can talk to your doctor about ways to preserve your fertility before starting treatment. Many women consider options such as freezing embryos (their own eggs fertilized with sperm from a partner or donor) or freezing eggs for later use. Another newer option is ovarian tissue freezing.
What is Ovarian Tissue Freezing?
Ovarian tissue freezing, also called ovarian cryopreservation, starts with a minor surgery to remove one of your ovaries. The outer layer of the ovary, known as the cortex, is separated from the rest of the tissue, sliced into multiple strips, and frozen. The cortex contains the immature eggs released every month as part of your menstrual cycle.
When you finish cancer treatment and want to get pregnant, a slice of that ovarian cortex is thawed and then implanted during another minor surgery, usually on the remaining ovary. Over the next few months, the implanted tissue should heal and connect to nearby blood vessels. The hope is that in 3 to 6 months, the tissue will start functioning again: hormone cycles come back, the body starts producing eggs, and periods return. Once your periods come back, you can try to get pregnant.
In selected cases, you might need to have in vitro fertilization, or IVF, to assist you in getting pregnant. IVF could be used if you don’t get pregnancy naturally or if you don’t have a male partner and wish to use donor sperm. Also, there are situations where the specialist has to implant the thawed ovarian tissue in the pelvic area but not directly on the ovary—for example, if you’ve had both ovaries removed or you have scar tissue on the ovary. To perform IVF, the specialist would harvest eggs from the implanted tissue, fertilize them in a lab, and then place the resulting embryos into the uterus.
Once the ovarian tissue starts functioning, it can last 4 to 8 years. If the implanted tissue stops working, or you want to have more children after 4 to 8 years, additional strips of tissue can be thawed and implanted.
Although the first ovarian tissue freezing and implantation procedure was performed in 1999, it’s often described as “experimental.” It’s only available in highly specialized centers, and fertility specialists are still investigating the best ways to do it. Ovarian tissue freezing is the only preservation option for girls who haven’t reached puberty and need cancer treatments that affect fertility, since their bodies are not yet producing eggs. And for younger women in their late teens and 20s, it can be a good option.
According to a 2017 study, about 37 percent of women who had ovarian tissue freezing went on to have successful pregnancies. The younger the woman was at the time of tissue removal, the greater the likelihood of success. For those 35 and older, which most women with breast cancer are, it’s not likely to be successful.
Who Can Get Ovarian Tissue Frozen?
The most commonly recommended fertility preservation option for women diagnosed with breast cancer is freezing embryos, followed by freezing eggs.
Ovarian tissue freezing might be considered if:
- A doctor recommends that chemotherapy start without delay: Egg or embryo freezing can delay the start of chemotherapy for several weeks. If you need chemotherapy as your initial treatment for breast cancer, or as soon as possible after surgery, you and your doctors might not want to wait that long. Ovarian tissue can be removed right away for freezing.
- You don’t want to take hormones to stimulate the ovaries: Women who want to freeze eggs or embryos need to take high doses of hormones to stimulate the ovaries to produce multiple eggs. If the cancer is hormone receptor-positive, there may be concerns about putting extra hormones into the body. Although you would be given high doses of aromatase inhibitors at the same time to keep estrogen levels low, you and your doctor still might prefer to avoid high doses of hormones.
- It’s likely that the ovarian tissue contains enough eggs: The younger you are at the time of ovarian tissue freezing, the better the odds of success when the tissue is re-implanted. If you’re older than your mid-30s or have had prior chemotherapy treatments, the odds of success are slim.
- You’re not at high risk of ovarian cancer: If you have a BRCA1 or BRCA2 mutation that increases ovarian cancer risk, freezing and later implanting ovarian tissue may not be the best choice for you.
- You want ovarian tissue freezing in addition to freezing eggs or embryos: With egg freezing, only about 10 to 15 eggs can be retrieved; even fewer embryos may result if a woman decides to fertilize the eggs before freezing. In contrast, a slice of ovarian tissue can contain hundreds or even thousands of immature eggs.
What are the Pros and Cons of Ovarian Tissue Freezing?
The advantages of ovarian tissue freezing over egg or embryo freezing are:
- it doesn’t have to delay treatment
- it does not require taking hormones. If you have hormone receptor-positive breast cancer, this may be a relief.
- each slice of tissue contains many more eggs than could be harvested during egg retrieval for egg or embryo freezing
- it returns your body to working as it did before menopause — releasing hormones, maturing an egg each month, and having regular periods
The main disadvantages of ovarian tissue freezing are that it
- is only available at highly specialized fertility centers
- is only recommended for women in their 20s and early 30s, and girls who have not yet reached puberty
- requires at least two surgeries
More About Ovarian Tissue Freezing
Women with breast cancer in their mid- to late-30s and 40s are not likely to have success with it. Also, women who had hormone receptor-positive breast cancer might be concerned about restoring the body’s production of estrogen.
According to the Society for Assistive Reproductive Technology, embryo freezing has the highest rate of success among fertility preservation methods, with about 45 percent of implanted embryos leading to delivery of a baby during a given cycle. If you choose to have ovarian tissue freezing, your team may suggest freezing embryos and eggs as well.
Reviewed by Kutluk Oktay, MD