Fertility
Is it safe to become pregnant after completing treatment for breast cancer?
For women who are planning on having a child but have yet to give birth, a breast cancer diagnosis can raise a number of questions. Among them are, “Will the hormones of pregnancy increase the risk of my cancer coming back?” and, “How long must I wait after completing treatment to have a child?” According to breast cancer surgeon Jeanne Petrek, M.D., it is important for a woman to allow herself enough time to regain the nutritional and metabolic health she needs to meet the demands of a pregnancy. Dr. Petrek, who serves as director of the Evelyn H. Lauder Breast Cancer Center at Memorial Sloan-Kettering Cancer Center, says that a key consideration is making sure that any aggressive disease that may have been underestimated does not come back.
Although there is no guarantee that the patient will remain cancer free, this is why doctors suggest waiting two or more years before becoming pregnant. It would be even better to wait five years, she says, if indeed a woman has that kind of time available. Often she does not. Dr. Petrek suggests that a woman consider those factors that govern her long-term health when considering a pregnancy. For instance, what was the stage of her cancer when it was diagnosed? Were her lymph nodes free of cancer at that time? What is her prognosis now? Another concern is that doctors don’t know exactly whether there is anything unique about one breast cancer versus another. Dr. Petrek explains that a woman may have had chemotherapy, but maybe the treatment merely damaged the cancer cells. Could they, perhaps, be dormant and come to grow again from the pregnancy?
What is unknown at this time is how to identify women in whom pregnancy is safe and women in whom it is not safe. “At present, there is no way to know,” she says. Dr. Petrek says that these concerns are theoretical because many pre-menopausal women—perhaps the large majority—do go on to safely become pregnant after breast cancer. The problem is that no long-term prospective studies have been completed at this time to provide solid answers for women. All past studies are retrospective and, she believes, scientifically weak. She has little confidence in these findings.
Meanwhile, a study led by epidemiologist Beth Mueller, Ph.D., a member of the Public Health Sciences Division at the Fred Hutchinson Cancer Research Center, and published in the journal Cancer in 2003 (Vol. 98, No. 6; pages 1131-1140), appears encouraging. This study retrospectively followed 438 women in Seattle, Detroit and Los Angeles. The women were younger than 45 years of age with primary invasive breast cancer, who gave birth after diagnosis. In addition, 2,775 comparison women, matched on the basis of a number of criteria, were identified with breast cancer—but without births after diagnosis. “The results of this study may provide some reassurance to young women with breast carcinoma in that subsequent childbearing is unlikely to increase their risk of dying,” says Dr. Mueller. “I can assure women that we conducted the study as carefully as possible, using the tools and data available at that time.
“It is reassuring that we did not observe an increased risk of mortality and that our results appear to be consistent with those from many other studies—including some studies using other designs,” continued Dr. Mueller. Although Dr. Mueller did not observe an increased risk for women who had births 10 months or more after their breast cancer diagnosis, relative to the control group who did not have children since diagnosis, she cautions readers to be careful not to over-interpret the results. She says that their finding of a decreased risk of dying may be due to what she calls a “healthy woman bias.” She explains that women who are healthier, or have a better prognosis, may be more likely to attempt pregnancies after diagnosis. “Although we attempted to control for this by using the data available about the severity of the women’s disease at diagnosis, we had limited knowledge about their health status afterwards,” she says.
Both researchers look forward to large population-based prospective studies in the years ahead, which would provide the best assessment of the question of an individual woman’s safety to proceed with pregnancy. Dr. Petrek, in fact, is currently recruiting women for two such trials to shed light on these and other quality-of-life questions, but her studies are just beginning and her findings a long way off. In the meantime, Dr. Petrek suggests that a woman who wishes to have a child confer with her family as well as with her health care providers—particularly a medical oncologist and a high-risk obstetrician. Dr. Mueller agrees and adds that each woman has a different situation regarding her own health status, social support and desire for offspring. “One’s decision may incorporate several factors including family cancer history, the presence of a supportive family and/or partner, and whether or not she already has children,” she says. “Ultimately, every woman faced with this scenario makes a personal decision based on her own situation.” “If there is any question,” Dr. Petrek adds, “adoption is a great way to go.”
This article first appeared in “Ask the Doctor” section of the winter 2005 issue of Lifeline
Young Women Face Fertility Challenges
Resource
Fertile Hope
www.fertilehope.org
(800) 994-HOPE
Founded in October 2001, Fertile Hope is a national nonprofit organization dedicated to providing reproductive information, support and hope to cancer patients whose medical treatments present the risk of infertility.
