Radiation and
chemotherapy treatment for cancer can cause
infertility in both men and women. High doses of
radiation and alkylating chemotherapy (such as chlorambucil, cyclophosphamide,
and nitrogen mustard) pose the highest risk of damaging egg and sperm. However,
some people suffer no fertility effects. Generally, the higher the dose and the
longer the treatment, the greater the risk to your fertility.1
Men
Whenever possible, men are advised to have some of their sperm
frozen (cryopreserved) in a sperm bank before cancer treatment. If you have had
cancer treatment in the past and have very low sperm counts, you may be able to
father a child using
assisted reproductive technologies called
intracytoplasmic sperm injection (ICSI) and
in vitro fertilization (IVF). In these, sperm are
collected then injected into your partner's egg, grown in the laboratory for a
few days, then transferred into her uterus. ICSI and IVF can also help you
conceive if you have no sperm in your semen.1 It is
possible that you still have immature, healthy sperm in your
testicles, which can be found and surgically removed
through a small incision (testicular biopsy), then used for ICSI.
Men who have low or no sperm count after cancer treatment may
gradually improve over a period of years.2
A small study has suggested that post-cancer-treatment sperm
generally have healthy DNA.2
Women
Eggs don't survive cryopreservation as well as sperm do, so
fertility-preserving treatment options are more complicated and/or experimental
for women than for men. They include:
- Delaying cancer treatment for a month or more,
and using in vitro fertilization (IVF) to produce
fertilized eggs (embryos or blastocysts) that can be
frozen for use in the future. IVF is only an option, however, for women who
don't have a type of cancer that is stimulated by estrogen—high estrogen levels
are necessary to stimulate egg production before harvesting them for IVF.
- Having all or part of an ovary surgically removed and frozen.
Early research has shown that when strips of thawed ovarian tissue are
re-implanted in the body after treatment, they can produce eggs for in vitro
fertilization.3 Some infertility clinics will
cryopreserve ovarian tissue for women who hope to use this experimental
procedure after cancer treatment, should it become available in the
future.
- Surgical placement of ovaries outside the radiation-affected area
of the body.
- "Shutting down" the
pituitary with a gonadotropin-releasing hormone
agonist (GnRH-a) during chemotherapy to protect the egg supply. One small study
of 34 women has suggested that this experimental treatment improved the chances
that a woman would resume ovulating 3 to 8 months after chemotherapy.3 (The same effects may not be seen for women receiving
high-dose chemotherapy before a bone marrow transplant.)