Every year in the U.S., approximately 1.5M people are diagnosed with cancer. Almost 10% of these new diagnoses occur in people who are 45 years old or under. Many of these 150,000 people have not yet had children, have not completed their families, or, in fact, are still children themselves. For these patients, preserving their fertility and protecting their parenthood options is an important part of their survivorship and life after cancer.
Cancer can take its toll on fertility in two ways.
First, the cancer itself may directly affect the reproductive system. This occurs when there is cancer of the reproductive organs including the ovaries, uterus, cervix and testes. Sometimes patients have impaired fertility, possibly due to the stress of their illness on the body, even before they begin their cancer treatments.
Second, the cancer treatment, including chemotherapy, radiation, and surgery can damage the reproductive system. Some treatments – certain chemotherapies and radiation – are gonadotoxic, meaning they will destroy sperm and eggs – and therefore cause infertility. Some treatments, principally surgery, but also radiation, can cause mechanical damage to the reproductive system, through the removal of reproductive organs or damage to their ability to function.
For more detailed information, see Factors Affecting Risk below.
Patient Population at Risk
About 10% of new cancer diagnoses in this country occur in patients age 45 and under, a time when many people are in the midst of building their families.
In the United States, many men and women are starting their families later than they used to. Data from the U.S. Centers for Disease Control and Prevention (CDC) show that the national average age for first births among U.S. women rose from 21.4 in 1970 to 25.0 in 2006. As a result, may patients who are diagnosed in their 30s or early 40s who may have completed their families a generation ago, today, may just being getting married and thinking about parenthood.
Survivorship rates are rising, too. The American Society of Clinical Oncology (ASCO) reports that an estimated 379,000 people in the United States are survivors of childhood and adolescent cancer, diagnosed before age 20. ASCO adds that 83% of children and adolescents diagnosed with cancer will live at least five years or more following their treatment. While this represents a great advance in treatment, many of these survivors are now facing the late effects of their earlier cancer treatments, including infertility.
Age and treatment type can influence a cancer patient’s risk of infertility.
Females are born with about two million oocytes (eggs). But as women get older, this number steadily decreases. Because treatment for cancer can damage oocytes and the follicles that produce them, older women have an even smaller reserve of oocytes available for fertilization, leading to even slimmer chances of fertility.
Chemotherapy drugs, alone and in combination, can damage egg and sperm cells themselves as well as reproductive organs and the glands that make important reproductive hormones.
Radiation can also damage eggs, sperm cells, and other important organs in its path. While a process called “shielding” can reduce the risk of damage from scatter radiation, at a certain level of exposure to radiation, cells will be damaged or destroyed.
For some patients, organs such as the ovaries or testes need to be removed completely. When this happens, patients are no longer able to produce gametes (eggs and sperm). Without gametes, biological parenthood cannot occur. In addition, women who have hysterectomies will not be able to carry a pregnancy.