Preserving fertility when you have breast cancer

Some women are able to become pregnant naturally after cancer treatment. But other women find that they are unable to have children after treatment. Being unable to have children can be very difficult to cope with. If you have not had children, or you would like to have more children, talk to your doctor about your fertility before you start your cancer treatment. Whether you will be able to have children afterwards depends on a number of factors, including how old you are when you have treatment.

There are now a number of ways of preserving fertility. Research is ongoing to find out how well they work and how safe they are for women with breast cancer. Finding a balance between your cancer treatment and wanting to have children is not easy. There is no guarantee of pregnancy with these methods of trying to preserve fertility.

Doctors are looking into preserving fertility by

• Using treatments to produce embryos or eggs for freezing
• Reducing the impact of chemotherapy on fertility
• Trying to preserve ovarian tissue for use in the future

The only medical treatment we have with a reasonable success rate in producing pregnancies is embryo preservation or IVF (in vitro fertilisation). With IVF you need to take hormones to stimulate your ovaries to make more eggs. The eggs then have to be removed and fertilised either with sperm from your partner or with donor sperm.

We don’t really know how this increase in hormones may affect women with breast cancer. There is some concern that the hormones could stimulate breast cancer cells to grow. IVF may also delay your breast cancer treatment because you might have to have egg collection and fertilisation done before you start.

Researchers are also looking into collecting eggs from the ovaries using smaller doses of hormones, or even no extra hormones at all. A procedure called natural IVF has been tested but it doesn’t produce many eggs and hasn’t been as successful as regular IVF. Doctors collect the eggs during your normal menstrual cycle.

Researchers have been testing different hormone therapies to stimulate the ovaries. These include tamoxifen and aromatase inhibitors either on their own or in combination with a lower dose of IVF hormones. Results are encouraging but we need more research to confirm how well this approach works.

Researchers are looking into freezing eggs (oocyte collection) rather than embryos. This method could be useful for women who have no partner at the time they need the egg preservation and don’t want to use donor sperm. It is very similar to IVF. Again, you need hormones to stimulate the ovaries to produce the eggs, which are collected and frozen. When you want to use the eggs they are thawed and injected with sperm to fertilise them. The problem is that freezing and thawing eggs seems to damage them and has not been very successful. So there haven’t been many live births with this treatment.

IVF is available for some people on the NHS but not in all parts of the country. The number of treatments you can have varies from area to area. You need to check with your doctor to find out what is available for you. If you need to pay for IVF yourself it is likely to cost several thousands of pounds per cycle.

Some chemotherapy drugs permanently stop the ovaries from producing eggs. If this happens, you can no longer get pregnant and you may have menopausal symptoms. Some women choose not to have chemotherapy because of this.

If you are concerned about your fertility, you can talk to your specialist about the risks and benefits of having chemotherapy or not. Some chemotherapy drug combinations, such as FEC or AC, are less likely to affect your fertility than others, such as CMF. Having FEC or AC doesn’t mean treatment definitely won’t affect your ovaries, but the risk is smaller. If you are over 40 there is a greater risk of fertility problems with any chemotherapy.

Researchers are also looking into using hormone treatment to protect the ovaries from chemotherapy. This means having injections of hormones called luteinising hormone blockers (LH blockers), for example goserelin (Zoladex), while you are having chemotherapy. The aim is that the LH blockers stop your ovaries working during the time you have treatment. Once your treatment has finished you stop the injections and your ovaries start working again. The evidence so far is mixed and we need more research to find out whether this does preserve fertility.

You can have a small operation to remove some ovarian tissue, which is then frozen. The tissue is put back once your cancer treatment has finished.This is a new treatment and very much in the early stages of development. There is very little evidence at the moment about how well it works but there have been reports of women having babies after this procedure.

Many women worry that pregnancy could increase the risk of their cancer coming back, or of a new cancer developing. The evidence so far suggests that pregnancy after breast cancer does not increase the risk of recurrence or a new cancer. Another concern is whether the breast cancer treatment increases the risk of birth defects or miscarriage. Again the evidence suggests that the treatment does not increase the risk.