Emerging data on pregnancy and cancer can now help women and their doctors chart a safer course between effective treatment and protecting the developing fetus.
Two registries – one in the United States and another in Europe – agree: It’s not only possible to save a pregnancy in many situations, but children born to these women appear to be largely unaffected by in utero chemotherapy exposure. The combined studies followed more than 200 exposed children for up to 18 years; neither one found any elevated risk of congenital anomaly or any kind of cognitive or developmental delay.
"This is practice-changing information," Dr. Frédéric Amant, primary author on the European paper, said in an interview. "Until now, physicians were reluctant to administer chemotherapy and usually opted for termination, or at least for a delay in treatment or premature delivery in order to get treatment going," he said.
Dr. Amant’s study leads off a special section on cancer in pregnancy, published in the March issue of Lancet Oncology. The paper examined evidence that both supports and questions the clinical wisdom of treating a disease that threatens two very different patients – an adult woman and the fetus she carries.
Every case is different, depending on the type of cancer, its grade and potential aggressiveness, the stage of pregnancy, and the woman’s own desires, said Dr. Elyce Cardonick, an ob.gyn. at Cooper University Hospital in Camden, N.J., and the lead investigator of the Pregnancy and Cancer Registry.
"With solid tumors you usually have time to do the surgery, get the pathologic diagnosis, and let the patient recover. But if there is leukemia, for instance, you have to move faster. The first question should be ‘Could we delay treatment for this patient if she was not pregnant?’ I don’t want to limit their treatment, but at the same time, it’s true that they might not be getting the most up-to-date treatment – the newest agent on the block – because you would want to go with something there is at least some experience with. But this doesn’t necessarily mean they are going to do worse."
Cancer occurs in about 1 in 1,000 pregnancies, said Dr. Sarah Temkin, a gynecologic oncologist at the University of Maryland, Baltimore. Many of her patients are referred after a routine screening during early pregnancy finds something abnormal, or when a woman with an existing cancer is incidentally found to be pregnant. But signs that might raise a red flag in other situations don’t necessarily alert physicians to danger in pregnant women, she said in an interview. Pregnancy could obfuscate some symptoms, which might be further downplayed in light of a mother’s relatively young age. Breast cancer is a prime example.
"There are two problems, especially for breast cancers, which are the most common ones we see in pregnancy. First, a woman’s breasts are changing anyway during that time. Breast cancer is so rare in women of earlier childbearing age that both the patient and the doctor tend to disregard any new lumps and bumps."
But despite its rarity, cancer in all forms appears to be increasing among pregnant women, she said. This is probably a direct relation to age. "Cancer rates increase with increasing age, and women are becoming mothers at older and older ages."
When cancer coincides with pregnancy, Dr. Temkin views the mother’s health as paramount. "The mother is the person with cancer, and she deserves whatever the standard of care is for that particular cancer – the best care that would be offered to her if she was not pregnant."
Chemotherapy and Fetal Outcomes
To examine long-term neurodevelopmental risks associated with maternal cancer treatment, Dr. Amant, a gynecologic oncologist at the Leuven (Belgium) Cancer Institute, and his colleagues, are following 70 children from the age of 18 months until 18 years. In the newly published interim analysis, the mean follow-up time is 22 months. All the children had intrauterine exposure to chemotherapy, radiation, oncologic surgery, or combinations of these.
The analysis, which also appeared in Lancet Oncology’s special issue, includes data on all the children, including 18 who are now older than 9 years (Lancet Oncol. 2012;13:256-64).
The children – 68 singletons and one set of twins – were born from pregnancies exposed to a total of 236 chemotherapy cycles. Exposure varied by the mother’s cancer type and its stage at diagnosis. In all, 34 mothers were treated with only chemotherapy, 27 had chemotherapy and surgery, 1 received chemotherapy and radiation, and 6 women were treated with all three modalities. Most of the children also had in utero exposure to multiple imaging studies, including MRI, ultrasound, echocardiography, CT, and mammography. Chemotherapy regimens included doxorubicin, epirubicin, idarubicin and daunorubicin.