Women, Fertility, and Cancer
Women who confront a cancer diagnosis before they make final decisions about parenthood and fertility often face difficult choices related to their treatment. The issue can create another incredibly emotional series of decisions to make amidst what is an already difficult time. The good news for patients today is that more information appears to be headed their way—making the various factors to be considered better-understood and the process more easily navigated.
In March 2004, a conference at the M.D. Anderson Cancer Center in Houston, Texas addressed the topic of parenthood after cancer. Options for preserving fertility, the safety of pregnancy after cancer, the health of children of cancer survivors and alternative routes to parenthood were all discussed. This broad conversation about fertility and cancer—and the increased attention it will bring to the topic—is welcome news for women who confront cancer before completing (or starting) their families.
Lindsay Nohr Beck, founder of the non-profit organization Fertile Hope, is among the women for whom the increased attention to the topic of fertility and cancer is especially good news. At the age of 24, Lindsay had a recurrence of a rare tongue cancer that required treatment with chemotherapy. She had concerns about how chemotherapy might affect her fertility, but her oncologist did not mention the issue when describing the risks of treatment. After thinking things over, and before starting chemotherapy, Lindsay herself decided to put her mind at ease by calling her oncologist and asking specifically about the risk of infertility. She learned that the risk was substantial.
Fertility After Cancer Treatment
For women, like Lindsay, who find themselves confronting treatment with questions about how their fertility may be affected, understanding how various treatments affect the reproductive system can help direct informed discussions with healthcare providers and can make treatment decisions easier.
Chemotherapy
Many chemotherapy drugs are toxic to the egg cells (oocytes) in the ovaries. Once oocytes are lost, the body does not replace them (although this belief was recently questioned by some scientists, based on research findings in mice).[2] If the number of remaining oocytes in the ovaries reaches a critically low point during treatment, women experience “acute ovarian failure.” This means that the ovaries stop functioning during or shortly after cancer treatment. If oocytes are lost during treatment but do not reach this critically low point, women are at risk for early menopause but may still be able to get pregnant for some time after treatment.
Radiation
Radiation to the pelvis can also destroy oocytes. Radiation to the pelvis can also affect uterine growth and blood flow, particularly if received before puberty.[3] A poorly developed uterus may make a woman more likely to have a miscarriage, or more likely to have a preterm or low-birthweight infant.
Age
Age is an important determinant of the effect of cancer treatment on fertility. Younger women, who have a larger pool of oocytes when they start cancer treatment, are more likely than older women to be able to get pregnant after treatment.[4]
Surgery
Some cancers require surgical removal of the uterus, the ovaries or both.
In Lindsay’s case, after learning that her chemotherapy regimen carried a high risk of infertility, she initially decided to refuse chemotherapy. But when her surgeon pointed out that she wanted Lindsay to be alive in five years and able to think about starting a family, Lindsay relented. She then began to search for ways to keep her reproductive options open.
Options for Preserving Fertility
If possible, women should talk with their doctor about their future fertility before beginning cancer treatment. Some options for preserving fertility require that steps be taken before cancer treatment begins.
One of the most established approaches for preserving fertility among female cancer patients is embryo freezing.[5] Before starting cancer treatment, a woman would be given hormones to stimulate the development of eggs in her ovaries. Mature eggs would be removed and fertilized with the sperm of her husband, partner or a sperm donor. The embryos that result from these fertilized eggs would be frozen for later use.
Although embryo freezing is an established approach to helping women become pregnant after cancer, there are downsides. A woman may not currently have a male partner and may be unwilling to use an anonymous sperm donor. This was the case for Lindsay, who said that being handed a catalog of sperm donors was more than she could handle at the time. The use of donor sperm can be “a sensitive topic,” she says.
Furthermore, if a woman has a cancer that is hormone-sensitive (such as many breast cancers), stimulating the ovaries may not be safe. To address this concern, scientists are exploring whether cancer drugs such as tamoxifen or letrozole may be used to stimulate the ovaries without increasing cancer risk.[6] In addition, embryo freezing takes
approximately two weeks after the start of a woman’s period. If a woman needs to begin cancer treatment immediately, she may not be able to go through this process. Finally, this approach is only an option for women of childbearing age; stimulating the ovaries to produce mature eggs is not an option for girls who develop cancer during childhood.
Several other options are still in the experimental phase. One approach being explored is the freezing of unfertilized eggs.5 Once again, the ovaries would be stimulated to produce mature eggs before cancer treatment begins. The eggs would then be frozen without being fertilized by sperm. Right now, freezing unfertilized eggs is less likely to result in pregnancy than freezing embryos, largely because unfertilized eggs are less likely than embryos to survive the process of freezing and thawing. Nevertheless, it may be an option for women who do not have a male partner at the time of their cancer diagnosis, and it avoids the difficult issue of what to do with unused embryos. Worldwide, more than 100 babies have been born through the use of this technology.[7]
As she was exploring her options, Lindsay was repeatedly told that egg freezing was not an option. Finally, after extensive searching on her own, she came across an experimental egg freezing program at Stanford University that was targeted toward young cancer patients. She made use of the remaining two weeks that she had before the start of chemotherapy to go through the process of treatment with fertility drugs and egg retrieval.
Another promising but still experimental approach is to freeze all or a part of an ovary before cancer treatment.[8] After treatment, the ovarian tissue is implanted either back in the woman’s pelvis or in another location (such as under her skin). If this process is successful, the ovarian tissue will begin producing eggs. A safety concern with this approach is the possibility of reintroducing cancer cells along with the ovarian tissue, and the tissue will need to be carefully screened for cancer before it is transplanted.[8]
Finally, it may also be possible to modify some cancer treatments to minimize their effects on subsequent fertility. For example, shielding the ovaries during radiation, or moving the ovaries out of the radiation field, may protect them from the effects of radiation. Scientists are also exploring whether using drugs to suppress the activity of the ovaries during chemotherapy will make the ovaries less susceptible to damage by chemotherapy.[9]For women with certain types of cervical or ovarian cancer, fertility-preserving surgery may also be an option.10 It’s important to understand that only specific subsets of patients will be candidates for these approaches, and that some of the methods are still in the early stages of evaluation.
Pregnancy After Cancer
In addition to having concerns about their ability to get pregnant, women may have concerns about whether pregnancy after cancer treatment will be safe for themselves and their children. While there is a limited amount of information about these topics, the news is generally good.
The risk of cancer recurrence during or after pregnancy has been most studied in women with breast cancer, and these studies generally have reported that pregnancy does not increase the risk of breast cancer recurrence.[11]Many doctors, however, suggest waiting for a period of time after treatment before becoming pregnant.[12]
If chemotherapy or radiation therapy has damaged her heart or lungs, a woman may also have concerns about the strain that pregnancy will put on her body. Studies of breast cancer survivors suggest that long-term heart problems are uncommon after chemotherapy or radiation therapy,[13] but a woman may wish to talk with her doctor about her current health status and the likely effects of pregnancy.
Women who have children after treatment for cancer in adulthood may be more likely than other women to have preterm or low birth weight infants. At least one study, however, suggests that the risk of perinatal mortality (death shortly before or after birth) is not elevated in infants of cancer survivors.[14]
Finally, children born after their mother’s cancer treatment do not appear to be more likely than other children to have birth defects or cancer.[15] If a woman’s cancer was due to a hereditary cancer syndrome, such as the hereditary breast and ovarian cancer syndrome caused by mutations in the BRCA1 and BRCA2 genes, her child may inherit the gene mutation responsible for her family’s increased risk of cancer. Talking with a genetic counselor may help clarify the child’s risk.
Other Options for Parenthood
Not all women have the luxury of being able to explore their reproductive options before beginning cancer treatment. And not all women will find a fertility preservation option that meets their needs. But there are still ways to become a parent. Discussion of other routes to parenthood may be a painful topic for women who want to become pregnant and cannot. But as cancer survivors consider how best to build their families, methods such as adoption are important options.
Adoption
Couples and individuals who wish to adopt have a range of options, including different types of domestic and international adoptions. When starting to consider adoption, Fertile Hope recommends that women learn about the laws in their state and talk with other adoptive parents about the professionals and agencies they worked with.[16] Before selecting an adoption agency, women may wish to talk with them about their attitudes toward placing a child with a cancer survivor. Many agencies will be receptive toward this, but it’s important to know before making a final decision.
Egg Donation
Women who still have a uterus may be able to become pregnant using an egg donated by another woman.[17] Through in vitro fertilization, the donated egg would be fertilized by the cancer survivor’s male partner or a sperm donor, and implanted in her uterus. Alternatively, another couple may donate a frozen embryo that could be implanted in her uterus.
Gestational Carrier or Surrogate
Women who do not have a uterus, or who are otherwise unable to sustain a pregnancy, may be able to have another woman carry a pregnancy for them.[18] If the cancer survivor has functioning ovaries, her own egg can be fertilized by her male partner’s sperm and transferred to the uterus of another woman. In this case, the woman who carries the pregnancy is known as a gestational carrier. If the cancer survivor does not have functioning ovaries, another woman can both donate an egg and carry the pregnancy. This is the arrangement traditionally known as surrogacy.
The cost, time involved, and success rates of each of these approaches vary widely. Talking with a doctor or getting information from organizations such Fertile Hope may help a woman find the option that is best for her.
Individual Decisions Within a Larger Community
The decisions that women make about building a family (or about coming to terms with not building a family) will be intensely personal; but women should know that they are part of a larger community of both cancer survivors who are voicing their needs and concerns, and clinicians and researchers who are realizing the importance of fertility and parenthood to young cancer survivors.
To think about future parenthood is to think about life after cancer. And for many cancer patients, planning for the future may provide the motivation they need to get through treatment.
In 2001, at the age of 25, Lindsay Nohr Beck started Fertile Hope (http://www.fertilehope.org/), a national nonprofit organization with the mission of “providing reproductive information, support and hope to cancer patients whose medical treatments present the risk of infertility.” Lindsay is now married and thinking about starting a family.
References:
[2] Johnson J, Canning J, Kaneko T et al. Germline Stem Cells and Follicular Renewal in the Postnatal Mammalian Ovary. Nature. 2004;428:145-50.
[3] Critchley HOD, Wallace WHB. Impact of Cancer Treatment on Uterine Function. Journal of the National Cancer Institute Monographs. 2005;34:64-68.
[4] Sklar C. Maintenance of Ovarian Function and Risk of Premature Menopause Related to Cancer Treatment. Journal of the National Cancer Institute Monographs.2005;34:25-27.
[5] Lobo, RA. Potential Options for Preservation of Fertility in Women. New England Journal of Medicine. 2005;353:64-73.
[6] Oktay K, Buyuk E, Libertella N et al. Fertility Preservation in Breast Cancer Patients: a Prospective Controlled Comparison of Ovarian Stimulation with Tamoxifen and Letrozole for Embryo Cryopreservation. Journal of Clinical Oncology. 2005;23:4347-4353.
[7] Winslow KL. Human Oocyte Cryopreservation. In: Fertile Hope 2005-2006 Cancer & Fertility Resource Guide.
[8] Roberts JE, Oktay K. Fertility Preservation: a Comprehensive Approach to the Young Woman with Cancer. Journal of the National Cancer Institute Monographs. 2005;34:57-59.
[9] Blumenfeld Z, Eckman A. Preservation of Fertility and Ovarian Function and Minimization of Chemotherapy-Induced Gonadotoxicity in Young Women by GnRH-a. Journal of the National Cancer Institute Monographs. 2005;34:40-43.
[10] Gershenson DM. Fertility-Sparing Surgery for Malignancies in Women. Journal of the National Cancer Institute Monographs. 2005;34:43-7.
[11] Blakely LJ, Buzdarm AU, Lozada JA et al. Effects of Pregnancy After Treatment for Breast Carcinoma on Survival and Risk of Recurrence. Cancer. 2004;100:465-9.
[12] Simon B, Lee SJ, Partridge AH et al. Preserving Fertility After Cancer. CA A Cancer Journal for Clinicians. 2005;55:211-228.
[13] Shapiro CL, Recht A. Side Effects of Adjuvant Treatment of Breast Cancer. New England Journal of Medicine. 2001;344:1997-2008.
[14] Fosså SD, Magelssen H, Melve K et al. Parenthood in Survivors After Adulthood Cancer and Perinatal Health in Their Offspring. Journal of the National Cancer Institute Monographs. 2005;34:77-82.
[15] Nagarajan R, Robison LL. Pregnancy Outcomes in Survivors of Childhood Cancer. Journal of the National Cancer Institute Monographs. 2005;34:72-76.
[16] Rosen AS. Adoption: An Introduction for Cancer Patients and Survivors. In: Fertile Hope 2005-2006 Cancer & Fertility Resource Guide.
[17] Westphal LM. Egg Donation. In: Fertile Hope 2005-2006 Cancer & Fertility Resource Guide.
[18] Brisman MB. Understanding Surrogacy. In: Fertile Hope 2005-2006 Cancer & Fertility Resource Guide.
