Breast Cancer Awareness: Can Cancer Treatments Affect Fertility?
October is Breast Cancer Awareness month and we’ve teamed up with Breast Cancer Now to bring you vital information about Breast Cancer during TTC, pregnancy, and postpartum. Today, we’re talking about breast cancer treatments and fertility.
Some treatments for breast cancer, such as chemotherapy, can affect your ability to become pregnant, and having breast cancer treatment may mean you have to think about your fertility sooner than you had planned.
While your main concern is probably treating your breast cancer, if having children of your own is important to you then procedures to preserve your fertility – such as IVF or freezing eggs – may be offered. It’s important to talk to your treatment team about this before your breast cancer treatment begins. Men who are treated for breast cancer can also discuss fertility preservation options with their treatment team.
We’re breaking down how female fertility works, how different cancer treatments might affect fertility, and possible fertility-preserving treatments.
Breast Cancer Now is there for anyone affected by breast cancer, providing support for today and hope for the future. Find out more at breastcancernow.org
Understanding fertility in women
To understand how breast cancer treatments might affect fertility and fertility-preserving treatments, it can be useful to know some basic facts about fertility in women.
Women are born with a set number of eggs in their ovaries (you do not produce new ones). By the time you’ve reached puberty, the number of eggs has already decreased, and the number continues to decrease as you get older. Generally, the quality of the eggs also reduces with age, which can affect fertility.
In a woman with “normal” fertility, at least one egg is released from the ovaries every month. Pregnancy occurs if an egg is fertilized by a man’s sperm and implants itself in the womb. If an egg is not fertilized, you have a period.
The ovaries stop releasing eggs, and monthly periods stop, when a woman reaches menopause around the age of 51, though studies show that women with an altered breast cancer gene (BRCA) may experience an earlier menopause.
How different breast cancer treatments can affect fertility
Chemotherapy:
Chemotherapy can cause infertility in women who have not been through menopause (pre-menopausal). It can affect the functioning of the ovaries, reducing the number and quality of eggs.
The likelihood of you having fertility problems in the future depends on the type of drugs used, the dose that is given, your age, and what your fertility was like before breast cancer treatment.
The chemotherapy drugs most likely to affect your fertility are a group called ‘alkylating agents’. One of these (cyclophosphamide) is commonly used in combination with other chemotherapy drugs to treat breast cancer. The effect of some other chemotherapy drugs, such as taxanes (docetaxel and paclitaxel), on fertility, has not been as widely studied, but evidence suggests they’ll also affect fertility.
Chemotherapy can cause your periods to stop. This may be temporary or permanent. In general the younger you are when having treatment, and particularly if you’re under 35, the more likely it is that your periods will return. Women over 35 are more likely to lose their fertility after chemotherapy.
It’s possible to stop having periods temporarily during treatment and to start having them again later, months, or occasionally even a few years after treatment has finished. If your periods return after chemotherapy, menopause is likely to happen sooner (up to 5–10 years earlier) than it would have done if you had not had chemotherapy. This may mean you have a shorter time to try to get pregnant.
If your periods do return, it does not always mean you’ll be able to get pregnant, so it’s important to speak to your treatment team if you have any concerns.
Hormone therapy:
Hormone therapies are used in women whose breast cancer is estrogen receptor-positive (ER+).
Some of the most commonly used hormone therapy drugs for pre-menopausal women with breast cancer are:
● Aromatase inhibitors (anastrozole, letrozole, and exemestane) alongside goserelin
In most pre-menopausal women who take tamoxifen, the ovaries continue to work. When you start taking tamoxifen it may stimulate ovulation (release of the egg from the ovary) and could make you more fertile. However, getting pregnant on tamoxifen is not recommended.
For some women, continued use of tamoxifen means periods become less regular, lighter, or stop altogether. Generally, your periods will start again once you stop taking tamoxifen, as long as you have not gone through menopause naturally while taking the drug. However, it may take four to five months for your periods to become regular again.
Goserelin switches off the production of estrogen from the ovaries. It’s often combined with other hormone therapies used to treat breast cancer, such as tamoxifen or aromatase inhibitors.
Hormone therapy is usually taken for five years or longer. While you’re taking hormone therapy you’ll be advised not to get pregnant as it may harm a developing baby. Even if your periods stop while you’re taking hormone therapy you could still get pregnant.
Due to the length of time, it’s taken, the side effects of hormone therapy may hide the signs of natural menopause. It may only be when you finish taking it that you realize you’ve started or been through menopause.
If you want to have children and you’re in your 30s or early 40s, taking hormone therapy for five years or more may be an issue you want to discuss with your treatment team.
Removal of the ovaries (oophorectomy):
Some women may have their ovaries removed as part of their breast cancer treatment, or as risk-reducing treatment if they have an altered gene. If you have had this operation you'll be left infertile but can consider egg or embryo donation in the future. See our information on surgery to remove the ovaries.
Referral to a fertility clinic
If you’re thinking of having children in the future, your breast cancer treatment team should offer a referral to a fertility specialist to discuss the option of preserving your fertility. This should be done as soon as possible after diagnosis to prevent any delays in your treatment.
Questions to ask at your fertility appointment
● Can I check if I’m fertile before my breast cancer treatment starts?
● How will my age affect my fertility?
● What are my chances of getting pregnant after treatment?
● How long after treatment will I have to wait to find out if I’m still fertile?
● How can I try to preserve my fertility?
● How much does fertility treatment cost?
● What does fertility treatment involve?
● How successful are the different methods of preserving fertility?
● Can I use a sperm donor?
If you’d like to see a fertility specialist and this has not been offered, ask your specialist or breast care nurse as soon as possible after your diagnosis to reduce any possible delays to your treatment. You can also ask to be referred to a fertility clinic that has experience in helping women having cancer treatment.
Options for preserving fertility before undergoing breast cancer treatment
Several procedures to preserve your fertility may be available to you before you start your breast cancer treatment. Your options could include:
● Having fertility preservation procedures
● Embryos freezing (IVF),
● Egg freezing
● Ovarian tissue freezing
● Ovarian suppression
Contraception during and after breast cancer treatment
Women are advised to avoid getting pregnant while having breast cancer treatment, as the treatment can damage an unborn baby at the early stages of development.
Your specialist is likely to advise using non-hormonal contraception, such as condoms, female condoms (Femidoms), or a diaphragm. It may also be possible to use a coil (IUD or intrauterine device). Speak to your treatment team as not all types are suitable for women with breast cancer – for example, the contraceptive pill is not advised after a diagnosis of breast cancer as it contains hormones.
The morning-after pill can be used in an emergency as it’s a single dose of hormones and unlikely to affect your breast cancer, but consult your doctor before taking any medication alongside your cancer treatment.
After treatment, your decisions about contraception will depend on how you feel about getting pregnant.
Find out more about planning pregnancy after breast cancer treatment.
More support from Breast Cancer Now
Whatever your feelings, you do not have to cope alone. You may find it helpful to share your thoughts with another person whose fertility has been affected by breast cancer treatment. More support from Breast Cancer Now (UK based):
● The Someone Like Me service can put you in touch with someone who’s had a similar experience to you
● Chat to other people with breast cancer on the online forum
● Meet other women at one a Younger Women Together support event
● Join the private Facebook group, set up by younger women with breast cancer, Younger Breast Cancer Network (YBCN). To access the group you’ll need a Facebook account and send a message to the group.
You can also call Breast Cancer Now’s Helpline to talk to a trained nurse.
More support & resources in the UK:
● British Infertility Counselling Association
A charity providing counseling and support to people affected by infertility. You can also find a counselor in your area.
Voluntary nationwide support group for women who experience premature menopause. Allows members to share information about their personal experiences of premature menopause.
An online community discussing infertility, adoption, parenting after infertility, and moving on.
Provides support and information, and promotes awareness of fertility issues. Also incorporates More to Life, a national charity providing support to people who are involuntarily childless.
An American patient information resource provided by the Oncofertility Consortium.
Support & resources in the US:
● National Breast Cancer Foundation
Provides early detection services, education, and support services.
Provides trusted resources, information, and support.
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