Breast cancer can be scary enough without wondering if it will also prevent you from having children. More and more American women are diagnosed with breast cancer in their childbearing years, and many want to know how the disease will affect their fertility.
While there's no one-size-fits-all answer to this complex question, WebMD asked the experts for answers to some tough questions including: What are risks posed by cancer treatment, methods of preserving fertility, and ways cancer might affect future offspring.
More than 11,000 women under 40 are diagnosed with breast cancer in the U.S. each year. How breast cancer treatment affects fertility depends largely on three factors: the type of treatment used, type and stage of the cancer at diagnosis, and the age of the patient.
Type of treatment
Not all breast cancer treatments affect fertility.
"If a patient needs only surgery and radiation and no chemotherapy, the treatment will have no impact on future fertility," Robert Barbierri, MD, chief of obstetrics and gynecology at Brigham and Women's Hospital in Boston, tells WebMD. The same, however, cannot be said for chemotherapy.
Breast cancer patients treated with chemotherapy run the risk of developing premature ovarian failure or very early menopause. Almost four out of five women treated with cyclophosphamide -- an often-prescribed chemotherapy drug for treating breast cancer -- develop ovarian failure, according to Kutluk Oktay, MD, assistant professor of reproductive medicine and obstetrics and gynecology at Cornell's Center for Reproductive Medicine and Infertility. FertileHope, a nonprofit organization dedicated to disseminating education on infertility associated with breast cancer treatment, places the risk at 40% to 80%.
Type and Stage of Cancer
How advanced a cancer is upon detection, as well as what type it is, dictate whether chemotherapy will be required, thereby affecting the risk of side effects to the ovaries.
The more advanced the cancer upon detection, the greater likelihood that chemotherapy, which affects the whole body, will be used to treat it. For instance, invasive breast cancer typically requires systemic chemotherapy, whereas a small tumor with small nodes that is localized and contains a minimal threat of spreading may not.
The type of tumor also impacts a patient's treatment options. Some breast cancers can be treated with the use of hormone-containing drugs. But a small percentage of breast cancer tumors are "hormonally insensitive," explains Susan Domcheck, MD, assistant professor of medicine at the University of Pennsylvania. What does this mean? "You can't use hormones to treat them. You're left with chemotherapy as your only option."
Age of Patient
Age plays a big role in patients' future fertility. "The age of the woman at the start of systemic chemotherapy is the biggest predictor of infertility," Barbierri tells WebMD. But why?
"If you're 30, your fertility is already declining. Add to that chemotherapy, and you tack on a few more years. We know that chemotherapy induces menopause, particularly with women over 40," Domcheck says.
Despite the fertility risks associated with breast cancer treatment (chemotherapy in particular), methods to preserve fertility prior to treatment offer hope to many patients.
To date, freezing embryos (fertilized eggs) created by in vitro fertilization (IVF) is the most widely used and effective method of preserving fertility. But there are potential downsides. IVF takes three to four weeks, a delay in cancer treatment that, depending on the stage and type of cancer, patients may or may not be able to afford. Sperm -- either from a partner or donor -- must be made available immediately to fertilize the eggs. And IVF is expensive -- anywhere from $10,000 to $14,000 per cycle.
Other methods of fertility preservation, albeit experimental, show promise. Egg freezing, which applies the same concept as embryo freezing, has proven less effective -- most likely because eggs are smaller, and less hardy, than embryos. There's also ovarian suppression during treatment, which "protects ovaries to some degree from chemical onslaught of chemotherapy," Barbierri tells WebMD. Freezing entire strips of ovarian tissue is a third technique under investigation; it involves surgically removing, storing, and later replacing the tissue in another part of the body.
Tamoxifen, a drug traditionally used to prevent breast cancer reoccurrence, was recently found to stimulate ovaries in breast cancer survivors during an IVF cycle, enhancing both egg and embryo production. This extra boost can combat infertility barriers such as age and the diminishing ovarian reserves, which occurs naturally with aging, notes Oktay.
Although males rarely develop breast cancer, it does happen. For male breast cancer patients who must undergo chemotherapy and want to preserve their fertility, freezing sperm is an effective option. "Since there are millions of sperm, even if you kill half in the freezing process, you still have a lot left," Barbierri explains.
Researchers' focus on fine-tuning methods of fertility preservation fuel optimism about its increasing viability. "A decade ago, there was practically no emphasis on fertility preservation. Today, there are several methods and thus a much greater potential," Oktay tells WebMD.
Conception Concerns: Relapse, Harm to Offspring
For survivors who remain fertile, questions about conception remain. Relapse is one of them.
"A common clinical recommendation is that a survivor wait two years before attempting to become pregnant, since most serious relapses will occur within the first two years after treatment," Barbierri tells WebMD. "If you wait two years, there's no strong evidence that pregnancy will influence the course of disease."
Survivors also worry that their offspring will be at risk for cancer. According to experts, that risk is small. "Only 5% of breast cancers are truly inherited via a specific genetic mutation," Domcheck tells WebMD. "If you have an inherited genetic mutation, you have a 50-50 chance of passing it on to your children." To date, researchers have identified a few genetic mutations that contribute to breast cancer; these include BCRA-1 and BCRA-2.
What is the prognosis for offspring who do inherit one of these genetic mutations? "There does not appear to be an increased risk of childhood cancers. However, these children are at a slightly higher risk for developing ovarian and breast cancers," Domcheck says.
But genetics are only part of the picture.
"It's likely that an interplay between a collection of genes, when added to certain environmental factors, results in breast cancer," Domcheck says. Known environmental risk factors include moderate or heavy drinking (for women, two or more drinks per day), having children later in life, and obesity.
Survivors also question the impact of cancer treatment on future offspring. The news on this front is very encouraging. "There does not seem to be any increased risk of birth defects if the woman who's gone through breast cancer treatment gets pregnant. Even if the woman gets chemotherapy during pregnancy, fetuses do surprisingly well," Domcheck tells WebMD.
Addressing Fertility With Your Doctor
Absorbing news of a breast cancer diagnosis as well as focusing on how it might affect future fertility can be overwhelming. But because oncologists are trained to provide the best cancer treatment available -- not necessarily in light of fertility options -- patients interested in seeking information on fertility need to be proactive.
"A patient needs to say to herself, 'What do I want in the future' and ask the doctor, 'What's this [treatment] going to do with my future plans for fertility?'" says Ann Partridge, MD, MPH, breast oncologist and instructor at Harvard School of Medicine in Boston.
Others agree. "You need to have as much information as possible," says Karen Dow, PhD, RN, professor at University of Central Florida's School of Nursing. She suggests getting a third or even fourth opinion, ideally from doctors in different specialties -- oncology, reproductive endocrinology, gynecology -- since each will bring a unique perspective unique to the table.
"It would be wonderful if, in the future, doctors would all come together to say, 'Hey, here's what's out there, here's what it means to you,'" Dow says. But for now, it's up to the patient to seek information on her options, as early as possible.