Creating a Family After A Cancer Diagnosis
When it comes to the fertility journey, all patients have their own unique story. As I sit at my desk following a Zoom call with one of my patients to discuss starting a frozen embryo transfer (FET) cycle for baby #2, a Zoom call which included both her husband and adorable 20 month daughter, I reflect on her initial journey, which she agreed to let me share. I first met this patient in 2017 when she was diagnosed with early stage breast cancer, for which she underwent a successful bilateral mastectomy with reconstruction. Thankfully, no chemotherapy or radiation was needed. At that time, she had a known history of BRCA2, which was diagnosed at age 25. During our initial consultation, I recall her stating she wished she met with a fertility specialist shortly after her BRCA2 diagnosis to review the implications and options related to her BRCA status and starting a family.
For those not familiar with the BRCA mutation, BRCA1 and BRCA2 are hereditary cancer syndromes which predispose individuals to certain types of cancer caused by these inherited genetic mutations. BRCA1 and BRCA2 mutations account for the majority of individuals with a hereditary breast and ovarian cancer syndrome, but other hereditary mutations exist as well. Women with a BRCA1 mutation have an estimated 50% to 85% risk of developing breast cancer by age 70. Their risk of developing ovarian cancer is 40% to 60% by age 85. Women with a BRCA2 mutation have the same percentage risk of developing breast cancer by age 70 and their risk for ovarian cancer is increased by 16% to 27%. Additionally, these women are at a higher risk of developing either breast or ovarian cancer at much younger ages than the general population and they are also at risk of developing additional types of cancers such as pancreatic cancer, melanoma, fallopian tube cancer, and primary peritoneal cancer.
In terms of my patient’s story, after being diagnosed with BRCA2 at age 25, she underwent biannual breast imaging and ovarian surveillance. At age 29, her plan was to start trying to conceive following her screening MRI of her breast. Unfortunately, the MRI was abnormal, ultimately resulting in the diagnosis of early stage breast cancer. She subsequently underwent successful surgery to remove the breast tumor. As a result of her breast cancer diagnosis and the BRCA2 mutation, she became interested in undergoing in vitro fertilization (IVF) with genetic testing to screen the embryo for the BRCA2 mutation. In general, children of BRCA mutation carriers have a 50% chance of inheriting the gene. As a result of what she experienced, she strongly desired to prevent her children from inheriting the BRCA mutation so they did not have to experience the constant fears and monitoring she herself endured, which still resulted in the diagnosis of breast cancer.
Women have the option of undergoing IVF with preimplantation genetic testing, currently referred to as PGT-M (formerly known as PGD- preimplantation genetic diagnosis), to screen embryos for a genetic mutation, and therefore prevent transmission of the genetic mutation to their offspring, and in this case end the BRCA cycle. PGT-M identifies embryos that are affected by the genetic mutation and those that are not. This allows couples to prevent a pregnancy with a specific genetic condition, such as BRCA. PGT-M is the only way to determine whether an embryo will be affected with a genetic condition prior to achieving pregnancy. This process requires a DNA sample from the patient and partner in order to create a “DNA probe” for the specific genetic mutation, which usually takes 4-8 weeks to complete. An IVF cycle involving PGT includes the process of fertilizing the egg, culture of the embryo to the blastocyst stage (a day 5 to 7 embryo), embryo biopsy, embryo freezing by vitrification, and DNA analysis to determine if the embryo carries the mutation for the specific genetic mutation (i.e. BRCA). In almost all PGT-M cycles, embryos also undergo preimplantation genetic testing for aneuploidy (PGT-A). This process allows us to identify the single healthiest embryo that is unaffected with the BRCA mutation and chromosomally normal (euploid). This is critical because embryos with chromosomal abnormalities (aneuploid embryos) are the leading cause of implantation failure and miscarriage, and these abnormalities naturally increase with maternal age. These screened embryos are later thawed and transferred in a FET cycle. Embryos not used can be saved for future attempts at pregnancy since these embryos can remain frozen indefinitely.
Conflicting studies exist regarding the effect of a BRCA mutation on fertility. There are multiple studies implying BRCA mutation carriers (more BRCA1 compared to BRCA2) may have decreased ovarian reserve (lower egg quality and quantity) compared with women without BRCA mutations. Some studies have also implied that BRCA mutation carriers undergoing IVF may not respond as well compared to non-BRCA carriers. However, there are other studies that have failed to demonstrate an association between BRCA status and fertility. In my patient’s case, she had diminished ovarian reserve (DOR), requiring 3 aggressive stimulation cycles in order to finally obtain 2 embryos that were chromosomally normal and unaffected with the BRCA mutation. I recall to this day the joy, excitement, and cries of happiness she expressed when I called her on a Sunday afternoon to inform her that her third cycle finally yielded two chromosomally normal and unaffected embryos. She then underwent a successful first FET cycle that resulted in the birth of her daughter.
The journey of this patient highlights a few key points. First of all, telemedicine, such as Zoom, allows us to further connect with our patients, and has become an essential part of patient care, which will last beyond the end of the pandemic. In addition, women with a hereditary predisposition to cancer are faced with complex challenges and need health care professionals to not only discuss the medical implications of their carrier status and risk-reducing options, but to also share information regarding fertility preservation (egg and embryo freezing) and the option of preimplantation genetic testing to prevent transmission of the genetic mutation to their offspring. It is important for women with a hereditary predisposition to cancer to know that there are ways they can safely build a family. In order to be as informed as possible about all of their options, women with a hereditary predisposition to cancer can benefit from reproductive counseling, which will improve their knowledge, and allow for more informed decision-making about reproductive options.