Certain cancers (especially testicular cancer) can severely impair sperm production, and cancer treatment (chemotherapy, surgery, and radiation therapy) can harm sperm cells. Cancer survivors typically have more problems with fertility than do couples who have never had cancer, and birth rates among cancer survivors are only 40 percent to 85 percent of the expected rates. Today, as millions of men of childbearing age are surviving cancer, the question of reproduction is arising as a paramount consideration in planning treatment.
In some cases, infertility also may be a symptom of some types of cancer, such as testicular cancer. Men who develop testicular cancer father fewer children and are more likely to have been diagnosed with infertility problems before their cancer diagnosis. Scientists suspect that inability to impregnate a woman may be a manifestation of unhealthy testes in which cancer eventually develops.
Danish researchers examining the relationship between increasing rates of testicular cancer and decreasing sperm quality also have concluded that men who have infertility problems have an increased risk of developing the disease. The study found a strong association between infertility problems and the subsequent risk of testicular cancer: Men in couples who had fertility problems were more than one and a half times more likely to have testicular cancer than other men. Men who had poor overall semen quality were two to three times more likely to develop testicular cancer.
Moreover, men who had a low sperm count who had fathered children in the past had a lower risk of developing testicular cancer than men who had been unable to father children.
In the Danish study, researchers analyzed the sperm quality of semen samples taken from more than 32,000 men in Copenhagen between 1963 and 1995. The risk remained constant over time, suggesting that sperm abnormalities had been present many years before the diagnosis of cancer. Researchers conclude that there may be common risk factors for poor sperm quality and testicular cancer and suggest that these factors may be present in the developing male fetus.
Patients who are concerned about the effects of cancer treatment on their ability to have children should discuss this issue with their doctor before treatment. The doctor can recommend a counselor or fertility specialist who can discuss available options and help patients and their partners through the decision-making process.
Radiation Therapy and Chemotherapy
Radiation therapy and chemotherapy treatments may cause temporary or permanent infertility, depending on a number of factors, including age at time of treatment, specific type and dosage of radiation therapy or chemotherapy, use of single therapy or multiple therapies, and length of time since treatment.
Direct radiation to areas such as the prostate or testicles may cause permanent sterility, and the closer the radiation treatments are to a man’s reproductive organs, the higher the risk of infertility. For men who receive radiation therapy to the pelvis, the amount of radiation focused directly on the testes is an important factor.
Fertility may be preserved by the use of modern radiation therapy techniques and of lead shields to protect the testes. Although men may not produce sperm for as long as five years after radiation therapy, sperm production may eventually recover.
In addition, radiation may make men too tired to be interested in sex. This loss of libido is a temporary side effect; once treatment ends and the body begins to return to normal, libido also usually returns.
After treatment for testicular cancer, radiation therapy does not usually cause sterility although a small dosage of radiation reaches the remaining testicle. There is no evidence that this radiation has any effect on children fathered after the treatment, but men are usually advised to use contraceptives for six to 12 months after treatment has ended.
Chemotherapy drugs (especially alkylating and platinum-based agents) and other drugs that can harm reproductive function tend to affect fertility in men. Age is an important factor for men receiving chemotherapy, and fertility recovery improves the longer the patient is off chemotherapy. Chemotherapy drugs that have been shown to affect fertility include busulfan, melphalan, cyclophosphamide, cisplatin, chlorambucil, mustine, carmustine, lomustine, cytarabine, and procarbazine. However, new combinations of cancer drugs are helping to improve fertility rates among these patients.
Men who have been diagnosed with testicular cancer are not necessarily infertile. The removal of one testicle does not affect sexual performance or ability to father children, as long as the other testicle is healthy, because the remaining healthy testicle produces more testosterone and sperm to compensate for the removal of the affected testicle.
Chemotherapy usually causes infertility for a short time after treatment for testicular cancer; although this is usually temporary, for some men it may be permanent. For this reason, it is usually advisable to store sperm before starting chemotherapy. The rate at which the sperm count recovers varies from person to person, but it generally returns to normal within two to three years.
Because the effect of chemotherapy on semen and sperm is uncertain, experts recommend that men use a condom during treatment and for about a month after treatment ends. This practice protects the man’s partner and avoids any stinging sensation.
Although there is no evidence that chemotherapy can harm children fathered after the treatment has finished, doctors usually advise that patients avoid having a child for six to 12 months after treatment.
Some men who have testicular cancer have a low sperm count before they start any treatment; sometimes successful treatment with chemotherapy may actually improve sperm production.
Sometimes doctors must surgically remove lymph glands in the abdomen if they are still enlarged after radiation therapy or chemotherapy. This removal can affect a man’s fertility, since the surgery can damage nerves that control the discharge of sperm through the penis. However, new surgical techniques can usually prevent this problem. If there is a possibility that a patient may need lymph surgery, patients may want to consider storing sperm samples before treatment starts. Although this further surgery may make fathering a child more difficult, it has no physical effect on the ability to have an erection or orgasm.
Preservation of Fertility
There are two ways a man facing treatment for cancer can preserve his fertility — either by banking his sperm before treatment or by attempting testicular tissue preservation.
Sperm banks are available where sperm are frozen and stored in liquid-nitrogen-cooled refrigerators. Specimens can be stored because the capacity of sperm to fertilize eggs does not change over an extended period.
Before undergoing treatment, patients should collect sperm specimens over at least two weeks. Sperm banks charge fees for freezing, storing, and retrieving sperm for the donor. Costs vary among institutions, and some portions are covered by some insurance companies. Since most physicians want patients to start cancer treatment shortly after diagnosis, it is important to locate a sperm bank as soon as possible so the patient can begin storing sperm.
Testicular tissue preservation
Testicular tissue preservation is an experimental procedure that has, as not yet resulted in any live births. In this procedure, testicular tissue and the sperm-producing stem cells are surgically removed, analyzed, and then frozen and stored. They are returned to the patient’s testicles after treatment is over. However, experts worry that it may not be easy to repopulate the specialized tubules in the testicles with sufficient stem cells to allow production of sufficient sperm for normal conception.
Testicular sperm extraction
Testicular sperm extraction is another method to preserve fertility that has resulted in a small number of births. If after cancer treatment a man is no longer producing sperm, his testicular tissue can be examined to see whether any sperm cells remain in the tissue. If so, the sperm can be removed and used in an in vitro fertilization procedure to produce pregnancy.
Pregnancy after Treatment
Cancer treatment may cause genetic damage to sperm cells exposed to chemotherapy or radiation for up to a year after treatment; therefore, experts recommend that men use a condom during this time. After one year, rates of birth defects in children born after one parent’s cancer treatment appear to be similar to those of the general population. No unusual cancer risk has been identified in the children of cancer survivors except in family genetic cancer syndromes.