by Eden Rauch, M.D.
Women who are recently diagnosed with breast cancer may now have new options to preserve their fertility and conceive after their treatment for breast cancer is completed. The state of NJ has mandated coverage of fertility preservation treatments for women of reproductive age who are undergoing chemotherapy or radiation for cancer. This article will discuss emerging new therapies for fertility preservation in women with a recent diagnosis of breast cancer.
Invasive breast cancer is the most common cancer in reproductive age women. Breast cancer accounts for one third of all cancers in reproductive women and affects tens of thousands of them each year. More than 90% of breast cancers are diagnosed at a local or regional disease stage with survival rates of 97% and 79%, respectively. Breast cancer is commonly treated with surgery followed by chemotherapy 6-8 weeks later.
The chemotherapy regimens used for treatment often result in infertility due to damage to the eggs in the ovaries and may cause premature ovarian failure. Furthermore, pregnancy is discouraged for greater than 2 years following treatment. With improved survival and cure rates for breast cancer, there have been recent advances in the field of fertility preservation which can permit many breast cancer survivors to have children in the future.
Ovarian stimulation with in vitro fertilization (IVF) and cryopreservation (freezing) of eggs or embryos (fertilized eggs) before the initiation of chemotherapy is the most established method for fertility preservation for these patients. IVF is a process by which egg cells are fertilized by sperm outside the womb, in vitro. The process involves administering fertility medications to induce multiple ovarian follicles containing eggs to grow, and removing eggs from the woman's ovaries and allowing sperm to fertilize them in a fluid medium. The fertilized egg or eggs are then transferred to the patient's uterus or frozen with the intent to establish a successful pregnancy in the future. Embryo freezing has been used for more than two decades to store excess embryos in women undergoing in vitro fertilization or to avoid the risk of ovarian hyperstimulation. The success rates of an IVF cycle using frozen, and then thawed embryos, has approached similar success rates to those using fresh embryos. Freezing of eggs is an emerging option suitable for reproductive age women, women without partners, or women who do not desire to have their eggs fertilized from a partner or an anonymous sperm donor. The egg cryopreservation technique is available to patients, but is still considered experimental with substantially lower pregnancy success rates due to technical challenges with egg survival as a result of the freeze-thaw process.
Conventional treatment regimens of ovarian stimulation for IVF are usually avoided since the high estrogen levels obtained with stimulation are considered possibly unsafe for patients with hormone sensitive cancers. Epidemiological and experimental evidence has suggested that estrogen and its by-products play a significant role in tumor growth in the breast tissue. Since ovarian stimulation increases the number of follicles containing eggs to grow and increases the estrogen production in proportion to the number of follicles recruited, estrogen levels can reach 10-fold or higher with in vitro fertilization in comparison to a natural menstrual cycle. Ovarian stimulation protocols using aromatase inhibitors such as Letrozole have been developed over the past several years and have been used to increase the margin of safety by helping to counteract the rise of estrogen levels during ovarian stimulation with in vitro fertilization. With aromatase inhibitors, estrogen levels are similar to a natural cycle, and egg and embryo yield are similar to conventional stimulated IVF cycles. Studies show that two year follow-up with regard to breast cancer recurrence and survival rates have been comparable to those of unstimulated breast cancer patients. Studies that investigate long term recurrence and survival rates are needed to confirm the short term safety data of ovarian stimulation protocols with aromatase inhibitors in the breast cancer population.
Many women with newly diagnosed breast cancer, who have not completed their childbearing, will choose to preserve their fertility. The impact of cancer treatment on fertility should be discussed with a young reproductive aged patient at the time of breast cancer diagnosis before initiation of treatment. In addition, a timely consult may be arranged with a reproductive endocrinologist to discuss fertility preservation options available to the patient. Several options are available to help preserve fertility in breast cancer patients undergoing chemotherapy. The most appropriate option should be decided based on the patient’s age, type of chemotherapy, the time available before chemotherapy begins, and the length of delay to childbearing after chemotherapy. Embryo freezing is the method with the highest success rate, and egg freezing should be considered in women who do not desire to use donor sperm. Both options involve a 2 week time period for ovarian stimulation beginning with the onset of the patient’s menstrual cycle. Other more experimental options include cryopreservation of ovarian tissue. The benefit of ovarian protection by medications called GnRH agonists is unconfirmed as a sole method of fertility preservation.
National organizations such as Fertile Hope, the Lance Armstrong Livestrong survivor care program and The American Fertility Association are dedicated to providing reproductive information, support and hope to cancer patients and survivors whose medical treatments present the risk of infertility.
Dr. Eden Rauch joined the IVF New Jersey team after completing her subspecialty training in Reproductive Endocrinology and Infertility at The Center for Reproductive Medicine and Infertility - a designated Center of Excellence within one of the world's leading teaching hospitals and medical research facilities, Weill Medical College of Cornell University.