Cautious Optimism for Offspring of Women with Cancer during Pregnancy.

Abstract

Fortunately, cancer rarely complicates pregnancy, with a cancer diagnosis in approximately 1 of 1000 pregnant women. Thus, for busy obstetrical care providers who deliver 125 babies per year, the odds that they will have a patient with cancer are about one in every 8 years. Given the variety of cancers that are diagnosed during pregnancy, it is unlikely that most obstetrical care providers will see more than two or three cases of any given type of maternal cancer in their careers. For similar reasons, most oncologists have limited familiarity with cancers that occur during pregnancy, as do most pediatricians who treat the babies of these women. Thus, all specialty care providers find themselves in unfamiliar territory when cancer is diagnosed in a pregnant woman. Much of the care of patients with cancer, including exposure to ionizing radiation at diagnostic and therapeutic levels and antimitotic chemotherapy, seems inimical1 to the healthy development of a rapidly growing fetus. These factors give all care providers pause and result in the dispensing of only tentative advice. In 2012, the National Toxicology Program of the National Institute of Environmental Health Sciences led a literature review of approximately 1050 publications dating back 50 years. This effort took nearly 18 months and resulted in a monograph describing the effects of scores of medications that are used for cancer chemotherapy during pregnancy.2 The data that are available in the literature are from case reports or small case series. The quality and completeness of such data are inconsistent and frequently lack critical information, such as dose, duration, cumulative dose, and timing of drug administration during gestation, along with data on maternal complications (e.g., anorexia, nausea, vomiting, and weight loss), neonatal birth weight, gestational age at delivery, cause of premature delivery, and (most important) follow-up of offspring beyond the immediate neonatal period. There is no widely publicized, readily accessible central registry for these reports or designated authority to assemble and curate a database that could be assembled from these reports, and there is undoubtedly bias toward adverse outcomes in reporting. A wide variety of agents are available to treat cancer, and they are usually used in combinations that make it very difficult to assign an observed toxicity to a particular agent. These factors make each patient nearly unique with respect to the combination of agents, doses, durations, and gestational ages at the time of administration. Since cancer among pregnant women is so rare, it takes quite a while to accumulate enough information to be confident about which toxic effects (including malformations) are associated with particular agents. Cancer chemotherapy has progressed so rapidly that by the time we think we know enough about the currently available agents to use them intelligently and counsel patients appropriately, the cancer community has moved on to newer, more efficacious, and hopefully less toxic agents for which we have little or no experience in pregnant women. Finally, for obvious reasons, there are no matched, untreated controls for comparison in such studies, which makes it impossible to distinguish the consequences of the cancer (anorexia, fever, weight loss, and dehydration) that might cause poor fetal growth, oligohydramnios, and preterm birth from some of the toxic effects of the chemotherapeutic agents used to treat the cancer. Amant and colleagues3 now report in the Journal the results of a comparison of pediatric outcomes between 129 children (including four sets of twins) of European women with cancer during their pregnancies and children born to women without cancer. They used the Bayley Scales of Infant Development to assess cognitive outcomes; they also assessed cardiac function on the basis of electrocardiography and echocardiography. Children who were exposed to maternal cancer were matched for sex, gestational age at birth, and age at the time of Bayley testing with children in a control group. A total of 96 children were exposed to 391 cycles of chemotherapy (alone or in combination with other therapies), and 11 children were exposed to radio-

DOI: 10.1056/NEJMe1512188

Cite this paper

@article{Greene2015CautiousOF, title={Cautious Optimism for Offspring of Women with Cancer during Pregnancy.}, author={Michael F. Greene and Dan L. Longo}, journal={The New England journal of medicine}, year={2015}, volume={373 19}, pages={1875-6} }