Cancer During Pregnancy: Rare But Increasingly Prevalent
Kerry was diagnosed with breast cancer while pregnant at 18 weeks; Trish, with Hodgkin lymphoma at 32 weeks; and Mara, a second breast cancer at 12 weeks.
Kerry and Mara delivered healthy daughters, and Trish, a son. Their stories, highlighted on the website Hope for Two…The Pregnant with Cancer Network, Amherst, NY, tell of the shock of learning about their cancer, the fear for their unborn babies while undergoing treatment, and their delight, years later, in being able to watch their children thrive.
The chance of being diagnosed with cancer while pregnant is rare: approximately one in 1,000. Breast cancer is the most common diagnosis, seen in approximately one in 3,000 pregnancies.1
However, cancers that occur more often in younger people are those that also tend to occur during pregnancy; these include cervical and thyroid cancer, Hodgkin lymphoma, non-Hodgkin lymphoma, and melanoma. Gestational trophoblastic tumor, albeit rare, may also be diagnosed.1 In addition, many women are becoming pregnant at older ages, and as a result, cancer incidence during pregnancy is increasing.2
One of the challenges in treating women who are diagnosed with cancer during pregnancy is its rarity. In fact, “few oncologists or obstetricians treat more than two or three patients in this situation in an entire career,” according to the Cooper University Health Care website.
To address this dearth of information, Elyce Cardonick, MD, an Ob/Gyn maternal-fetal medicine specialist at Cooper University Health Care, Camden, NJ, who is on the Hope for Two advisory board, maintains the Cancer and Pregnancy Registry, a database of all pregnant women diagnosed with cancer, which follows their children not only until birth, but ongoing annually.
“Pregnant women diagnosed with cancer find the registry helpful in learning how many other pregnant women were diagnosed and treated for the same cancer during pregnancy,” Cooper noted.
That is also the rationale behind Hope for Two, which is “dedicated to providing women diagnosed with cancer while pregnant with information, support, and hope.” The organization was founded in 1997 by three women who were diagnosed and treated for cancer while pregnant. To date, Hope for Two has counseled and supported, worldwide, more than 950 women in this predicament.
While 70% of these women have received a diagnosis of breast cancer, 28 types of cancer are represented. “Women find it important to speak with another woman who has had the same type of cancer and stage; Hope for Two provides that support,” they note.3
Interpreting the Signs of Cancer Through Pregnancy
Cancer during pregnancy may confound initial diagnosis. Many symptoms of cancer—abdominal bloating, frequent headaches, rectal bleeding—are common during pregnancy and may elude suspicion. Pregnant women with breast cancer are often diagnosed 2 to 6 months later than nonpregnant women due to enlarged breasts (making it difficult to detect small tumors) and avoidance of mammograms during pregnancy.
In some cases, routine tests or examinations conducted during a pregnancy will reveal an underlying cancer, such as cervical or ovarian. Diagnostic x-rays and CT scans are considered safe during pregnancy, with the exception of the abdomen or pelvis, which should only be radiated if necessary. MRIs, ultrasound, and biopsies are also deemed safe during pregnancy.1
The cancer itself rarely harms the fetus. Therefore, treatment options are determined based on gestational age of the fetus and characteristics of the tumor, such as type, size, and stage.4
The type of treatment for cancer—surgery, chemotherapy, and radiation therapy—is determined by weighing the best options for the mother, while avoiding risk to the fetus. For that reason, treatment is often delayed until the second or third trimester. If diagnosed late in the pregnancy, treatment may be delayed until after birth, or labor may be induced.
Pregnancy Outcomes After Cancer Diagnosis
Recent literature has focused on outcomes of women diagnosed with cancer and treated during pregnancy. Walsh and colleagues from Mater Misericordiae University Hospital in Dublin, Ireland, retrospectively identified women diagnosed with cancer during pregnancy during a 25-year period to determine “if all cancers needed to be treated in pregnancy or if treatment could be safely deferred to allow normal delivery.”5
Median age of the 25 women referred to medical oncology was 33 years (range, 20 to 42 years) and gestation at diagnosis, 14 weeks (range, 6 to 36 weeks). Of these, 16 (64%) received doxorubicin and cyclophosphamide during pregnancy (13 for breast cancer, one for Ewing's sarcoma, one for ovarian cancer, and one for small cell cervical carcinoma). At a median follow-up of six years, 11 (69%) of the mothers were disease free and four (25%) had disease recurrence.
Of nine women who did not receive chemotherapy during pregnancy, six (86%) were diagnosed at a median gestation of 13 weeks. Seven received chemotherapy immediately postpartum (three for Hodgkin lymphoma, two for breast cancer, and one for ovarian cancer), and two did not receive chemotherapy. At a median follow-up of 12 years, all mothers were free of disease.
“We did not identify any adverse outcomes in mothers or infants exposed to chemotherapy during pregnancy,” the authors reported. “In selected cases, it is safe and appropriate to delay chemotherapy until delivery of the baby. There were no adverse outcomes to mothers due to delayed treatment and no adverse outcomes to babies not exposed to chemotherapy in utero.”5
Similarly, a case series based on data from the Cancer and Pregnancy Registry reported by Dr. Cardonick found that “taxane-based chemotherapy does not appear to increase the risk of fetal or maternal complications when compared with conventional chemotherapy in the small cohort of women in our registry.”6
In 2008, the MotHER registry—the first prospective study of the effects of a targeted cancer therapy on pregnancy outcome—was established as a U.S. Food and Drug Administration (FDA) postmarketing commitment from Genentech Inc., San Francisco, CA.
Brown et al reported at the 2013 annual meeting of the American Society of Clinical Oncology that oligohydramnios, an amniotic fluid deficiency, had been reported in patients who received trastuzumab during pregnancy as well as in pertuzumab-treated pregnant monkeys. “Although both agents are FDA Pregnancy Category D, indicating evidence of fetal harm, some physicians and patients accept this risk and continue treatment,” they noted.7
Women are voluntarily enrolled in MotHER if they received either trastuzumab or pertuzumab during pregnancy or within 6 months prior to conception and are followed until pregnancy outcome, a primary study end point. In this program, infants are followed through their first year of life.
Other primary end points are number and nature of pregnancy complications, including oligohydramnios, and fetal/infant outcomes and/or functional deficits. The registry will accrue until 2019 for women treated with trastuzumab and 2022 for those treated with trastuzumab and pertuzumab.7, 8
A cancer diagnosis during pregnancy can be a daunting experience because the woman has to consider her baby's health as well as her own. However, with the proper knowledge of treatment options and support from her healthcare team, the outcome for both mother and baby can be a positive one.
1. American Society of Clinical Oncology. Cancer.net. Cancer During Pregnancy. Available at: http://www.cancer.net/coping/emotional-and-physical-matters/sexual-and-reproductive-health/cancer-during-pregnancy. Accessed July 29, 2013.
2. Cooper University Health Care. Cancer and pregnancy. Available at: http://www.cooperhealth.org/departments-programs/cancer-and-pregnancy. Accessed July 24, 2013.
3. Hope for Two. The Pregnant with Cancer Network. Available at: http://www.pregnantwithcancer.org/survivor_stories.php?StoryID=16. Accessed July 23, 2013.
4. U.S. National Library of Medicine. Cancer and pregnancy. Available at: http://www.nlm.nih.gov/medlineplus/cancerandpregnancy.html#cat27. Accessed July 23, 2013.
5. Walsh E, O'Kane G, Cadoo KA, et al. Cancer in pregnancy: To treat or not? J Clin Oncol. 2013;31(suppl; abstr e12533).
6. Cardonick E, Bhat A, Gilmandyar D, Somer R. Maternal and fetal outcomes of taxane chemotherapy in breast and ovarian cancer during pregnancy: case series and review of the literature. Ann Oncol. 2012;23(12):3016-3023.
7. Brown V, Partridge A, Chu L, Szado T, Trudeau C, Andrews EB. MotHER: A registry for women with breast cancer who received trastuzumab (T) with or without pertuzumab (P) during pregnancy or within 6 months prior to conception. J Clin Oncol. 2013;31(suppl; abstr TPS658).
8. ClinicalTrials.gov. An observational study of pregnancy and pregnancy outcomes in women with breast cancer treated with Herceptin or Perjeta in combination with Herceptin during pregnancy or within 6 months prior to conception (mother). NCT00833963. Available at: http://clinicaltrials.gov/show/NCT00833963. Accessed July 23, 2013.