The main goal of any cancer treatment is to prevent the cancer from spreading and coming back and to improve survival. Unfortunately, as a result, cancer treatment can impact fertility. It can cause temporary menopause (amenorrhoea) where the period stops for some time. While your periods may return, it does not necessarily mean that it will be easy to fall pregnant. Cancer treatment can also cause permanent menopause, where menstruation stops permanently and natural pregnancy is highly unlikely.
The chance of becoming menopausal as a direct result of your cancer treatment is largely dependent upon your age and the specific type of treatment you are given.
The risks of infertility caused as a direct result of cancer treatments can vary based on the drugs used to treat your cancer type, and how long you are taking them.
Speaking with your doctor about the risks of infertility based on each new treatment option you use is essential to both manage and support you during this period.
Fertility treatment options aim to improve your chances of having children in the future. However, it is important to speak with your medical team to determine how long you have available to make these decisions prior to commencing treatment. Generally, putting off treatment for a short time won’t change how effective it is, whilst still allowing you the time to get all the information and resources you need. That said, not all cancer diagnoses will allow for this, so being as educated as possible about fertility generally is incredibly important to ensure you can make educated decisions as quickly as possible, should an unexpected diagnosis occur.
Radiotherapy
Radiation therapy uses x-rays to damage or kill cancer cells in order to prevent them from growing and multiplying. It can be delivered either externally via beam radiation or given internally. The risk of infertility as a direct result of radiotherapy will vary depending upon the area being treated and the dose.
- External or internal radiotherapy given to the pelvic area for gynaecological cancers can stop the ovaries producing hormones and can result in temporary or permanent menopause.
- Treatment to the pelvic area can also increase the risk of miscarriage, premature birth and lower birth weights.
Surgery
Surgery that removes parts of, or all of, the reproductive organs including the ovaries, fallopian tubes, uterus and cervix, can cause infertility.
- Removal of the uterus and cervix (hysterectomy)
Usually, the method used to treat gynaecological cancers, such as cancer of the cervix, ovary, uterus, and endometrium and sometimes, cancer of the vagina. Following a hysterectomy, you will be unable to fall pregnant and periods will stop.
- Removal of the ovaries (oophorectomy)
If both ovaries are removed (bilateral oophorectomy) and you have not yet been through menopause, you will be put into surgical menopause. You will no longer have periods or be able to become pregnant naturally.
It’s important to note that when cancer treatments cause early menopause the impact upon your emotions, body image and relationships can be significant. It is so important, regardless of your life stage, to talk to a family member, friend or counsellor to guide you through this time.
Chemotherapy
You may be advised that chemotherapy is the necessary treatment option following surgery. Many patients are. Chemotherapy is used to destroy cancer cells that may have spread throughout your body and can subsequently impact your fertility by damaging your ovaries and eggs.
As women, we are born with a fixed number of eggs and are unable to make more, so protecting them prior to commencing treatment is something women need to consider.
The effects of chemotherapy are entirely dependent not only upon your age, but also the specific type of drug used. For some women, this means they are able to fall pregnant easily following treatment, however some may have trouble conceiving. Women who are older already have fewer eggs, so by the end of treatment may unfortunately be left with nothing.
Chemotherapy can lead to:
- Premature permanent menopause – where periods do not return after chemotherapy;
- Temporary menopause – periods may stop for a year or more; and
- Early onset (permanent) menopause – even if periods do return, menopause happens up to seven years earlier than if there had been no chemotherapy.
Menopause is reached when the number of potential eggs drops below a certain amount. Chemotherapy reduces this number meaning that menopause is more likely to occur at an earlier age than it would without this type of treatment.
Trastuzumab (herceptin)
Herceptin is usually used for up to a year following a breast cancer diagnosis and treatment, however, it is not believed to reduce an individual’s fertility. If your breast cancer contains extra copies of the HER2 gene, Herceptin helps to reduce your risk of the cancer coming back.
While the effects of Herceptin on pregnancy are unknown, it is best to avoid falling pregnant whilst on Herceptin. For more information relating to this particular treatment, it is best to speak directly with your medical team.
Hormone (endocrine) therapy
Hormone therapies for cancer treatment are not known to cause menopause, however, because hormone therapy can continue for up to 10 years following a breast cancer diagnosis, fertility will decline during this time. Generally, the older a woman is when she starts endocrine therapy, the lower her fertility will be once treatment is complete.
While it is possible to have a break from hormone treatment to try for a baby, there is no evidence to suggest that this is a safe thing to do. If you wish to explore this option whilst on hormone therapy, it is best to speak directly with your oncologist to consider what updated research is available to weigh up the pros and cons.
The majority of breast cancers are dependent on the ovarian hormones, oestrogen and progesterone, which can stimulate cancer cell growth ad are called hormone receptor-positive breast cancers.
Hormone therapy is advised for women who have this type of breast cancer to block the effects of oestrogen in the body. Drugs include tamoxifen, aromatase inhibitors such as exemestane or letrozole and GnRH agonists such as Zoladex.
Tamoxifen is considered an anti-oestrogen option that can halve the risk of cancer returning if taken consistently for 5-10 years.
Women taking tamoxifen should not use hormonal contraception.
Zoladex is an injectable option that suppresses the ovaries and brings on temporary menopause and can be given at the same time as tamoxifen, and some studies indicate that it has been known to further reduce the risk of breast cancer returning and menstrual periods will stop temporarily whilst on Zoladex.
Recent research has shown the combination of an aromatase inhibitor with a GnRH agonist will help to reduce the risk of cancer returning in certain premenopausal women and is something that should be considered and discussed with your oncologist.
