Article: Preimplantation genetic diagnosis and hereditary cancer
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Preimplantation genetic diagnosis () is testing that is used in combination with in vitro fertilization () to help to identify genetic defects within embryos before they are transferred to a womb. The goal of is to prevent inherited genetic diseases or disorders from being passed on from the parent to a child. The technology was first developed in the 1990s and has advanced over time.
There are a number of situations in which patients may benefit from , including when one or both partners has a history of an inherited genetic disorder or when one or both partners tests positive for a mutation that could cause disease in their offspring. Examples include recessive genetic diseases, (i.e. Tay-Sachs or cystic fibrosis), X-linked genetic diseases (i.e. hemophilia or Duchenne muscular dystrophy), and dominant genetic diseases, (i.e Huntington’s disease or a mutation).
Preimplantation genetic screening (PGS) is another screening technique which identifies chromosomally normal (46 chromosomes) embryos prior to embryo transfer. Those who may benefit from PGS include women who are over the age of 35, have a history of failed , or couples with a history of recurrent miscarriages. Couples with a predisposition to a genetic disorder undergoing to prevent having a child with the disorder may also undergo PGS at the same time to determine if the embryo is chromosomally normal.
Joseph’s article highlights the story of a woman with a mutation who, before undergoing surgery to remove her ovaries, underwent fertility preservation and ended up with only one viable embryo. After she knew the frozen embryo carried the mutation, but she chose to go ahead and have the embryo implanted in her womb. She currently has a healthy son, and while concerned about the fact that since he carries a mutation he is at higher risk of cancer or may possibly pass on the mutation to his children, she is very happy that she went through with the pregnancy.
Not everyone is comfortable with the concept of and screening embryos for mutations. Nevertheless, it is an option available to patients and an increasing number of people with inherited disorders are undergoing and . For this reason, it is important for people considering these procedures to understand what they entail.
For parents who carry a or other genetic mutation who are considering fertility treatments, it is important to know that:
- You, your partner and the clinician are usually involved in decision-making. Considerations include what a clinician is comfortable doing, and what the potential parent or parents want — and couples don't always agree.
- There is no guarantee that an embryo will result in a live birth.
- Having a genetic mutation does not guarantee a diagnosis. For example, can tell parents if an embryo carries a mutation, but it cannot tell them if or when an adult child may develop cancer.
- Insurance does not typically cover the cost of or . While there are some resources available to help defray costs, many are available only to cancer survivors and not previvors.
As genetic testing is moving out of a clinical setting and directly into the hands of consumers it is increasingly important for parents to understand the limitations of genetic testing. Not all genetic information is equally useful for making real-life medical decisions.
Joseph reports that although doctors in the United Kingdom are not permitted to transfer embryos with abnormalities that may cause serious diseases or disabilities unless there are no other viable embryos, the United States has no regulations regarding when to transfer embryos with genetic abnormalities. In a paper published earlier this year, Daar, Klipstein, and colleagues on the American Society for Reproductive Medicine’s ethics committee highlighted the ethical concerns involved in transferring embryos with genetic anomalies including patient autonomy, the rights and well-being of the offspring, and clinician choice among them. Their goal was to at least provide a foundation for ways to think about the issues.
There is some disagreement among some experts and advocates as to whether should be available for all inherited mutations. Concerns have been raised over whether some diseases do not impact overall health enough to justify . Clinicians may encounter patients who will want to select an embryo with a certain genetic trait. While this is rare, experts state this sometimes happens in cases where the parents are deaf or have dwarfism and want their children to have the same traits.
It is important to make sure that as experts debate the issues, the patient perspective is considered as well. In 2009, FORCE and colleagues from the University of South Florida and Moffitt Cancer Center conducted and published results of a survey of people with on knowledge of, and attitudes about .
can test for more than 100 different genetic conditions. The procedure is performed before implantation which allows the couple to decide if they wish attempt a pregnancy. The procedure enables couples who might not have otherwise pursued biological children to do so.
For families with inherited disorders who have witnessed the devastating impact of inherited disease, this may be strong motivation for choosing .
However, there are concerns with testing as well. For other families, these technologies may be equated with “playing God.” People who believe that life begins at conception may consider the destruction of an embryo as the destruction of a person. While helps to reduce the chances of conceiving a child with a genetic disorder, it cannot completely eliminate this risk. Also, keep in mind that does not replace the recommendation for prenatal testing.
As Judith Daar, a bioethicist and clinical professor at University of California, Irvine, School of Medicine states in the piece, “The technology is marvelous and can be predictive and accurate, but we’re probably at a very nascent of understanding the impact of what the genetic findings are on health.”
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This article is relevant for:
people with an inherited mutation linked to cancer risk
This article is also relevant for:
Breast cancer survivors
People with a genetic mutation linked to cancer risk
Women under 45
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The National Comprehensive Cancer Network (NCCN) provides guidelines for fertility in people diagnosed with cancer.
The NCCN recommends doctors discuss the following with adolescents and adults with cancer before treatment begins:
- fertility plans and preferences
- fertility preservation options, including:
- whether therapy can be delayed long enough for a cycle of egg stimulation
- medications like GnRH agonist therapy during to preserve ovarian function in premenopausal women with breast cancer
- importance of follow-up with a gynecologist or fertility specialist to monitor ovarian function over time
- risks for infertility due to cancer and related treatment
- affects of treatment on breastfeeding
- the importance of avoiding pregnancy and options for safe and effective birth control while in treatment
- safe timing for considering pregnancy after treatment
- emotional impact of discussions about fertility preservation
- financial resources for fertility preservation
- effects of treatment on sexual function during and after treatment
Doctors should refer patients as indicated for the following services:
- All patients who are interested in preserving their fertility should be referred to a fertility preservation clinic before starting treatment.
- Patients who need assistance with complex medical decision-making should be referred to a mental health professional.
- Patients who are experiencing sexual disfunction should be referred to a sexual health specialist.
- What are the key points to consider when balancing family planning with cancer risk reduction?
- I want to have children, what are my options for managing my risk for cancer?
- What are my options if I wish to undergo In Vitro Fertilization and Preimplantation Genetic Diagnosis?
- How does and childbearing affect my risk for cancer?
- Will my insurance pay for and ? Are there resources to help defray the costs?
The following research studies related to fertility preservation are enrolling patients.
Fertility preservation studies for women
- NCT01503190: The Immune System's Response to Young Women's Breast Cancer. This an observational trial looking at tissue samples from patients with Pregnancy-Associated Breast Cancer (PABC) versus non-PABC to understand how the immune system responds.
- NCT05443737: Evaluation of a Telehealth Oncofertility Care Intervention in Adolescent and Young Adult Cancer Patients. The purpose of this study is to evaluate the effectiveness of an intervention to improve young cancer survivors' oncofertility care.
- NCT0301168: Fertility Preservation Using Tamoxifen and Letrozole in Estrogen Sensitive Tumors Trial (TALES). Infertility as a result of cancer treatment effects long-term quality of life in survivors of reproductive-age cancers. This trial will study different options for fertility preservation in patients with estrogen-receptor-positive breast cancer.
- NCT00823654: Serum Biomarkers to Characterize the Effects of Therapy on Ovarian Reserve in Premenopausal Women With Breast Cancer or Mutations. This study will look at how cancer treatment affects the ovaries. Researchers will review blood samples before, during and after cancer treatment to look at levels of hormones that are produced by the ovaries and ask patients to fill out questionnaires about their menstrual cycles (periods), overall health and pregnancies.
- NCT01788839: Longitudinal Sexual and Reproductive Health Study of Women With Breast Cancer and . This study looks at how cancer treatment affects sexual and reproductive function. The patient will be asked to give a blood sample to see if and how cancer treatment affects the ovaries and the ability to have children (fertility). These blood draws are optional; patients can participate in the study questionnaire even if they choose not to have their blood drawn.
- NCT01558544: Cryopreservation of Ovarian Tissue. The study hopes to contribute to the development of technologies of ovarian tissue freezing-thawing the preserve fertility. The study is open to women who will undergo treatment or surgery for cancer or women with an inherited mutation who are considering undergoing risk-reducing surgery.
- NCT01788839: This study's goal is to see how cancer treatment affects sexual and reproductive function. Participants will also be asked to participate in optional blood tests to see if and how cancer treatment affects the ovaries and the ability to have children.
Fertility preservation for men
- NCT02972801: Testicular Tissue Cryopreservation for Fertility Preservation. Testicular tissue cryopreservation is an experimental procedure where testicular tissue is retrieved and frozen. This technique is reserved for young male patients, with the ultimate goal that their tissue may be used in the future to restore fertility when experimental techniques emerge from the research pipeline.
FORCE offers many peer support programs for people with inherited mutations.
- Our Message Boards allow people to connect with others who share their situation. Once registered, you can post on the Diagnosed With Cancer board to connect with other people who have been diagnosed.
- Our Peer Navigation Program will match you with a volunteer who shares your mutation and situation.
- Our moderated, private Facebook group allows you to connect with other community members 24/7.
- Check out our virtual and in-person support meeting calendar.
- Join one of our Zoom community group meetings.
If you are in your reproductive years and have been diagnosed with cancer, or you are considering steps to lower your cancer risk that will interfere with your fertility, you should request referral to a fertility expert.
- The Oncofertility Consortium maintains a national database of healthcare providers with expertise in fertility preservation and treatment of people who are diagnosed with cancer or at high risk for cancer due to an inherited mutation.
- Register for the FORCE Message Boards to get referrals from other members. Once you register, you can post on the Find a Specialist board to connect with other people who share your situation.