Chemotherapy Safe During Pregnancy in Second and Third Trimesters
Vienna, Austria—Results from a new study provide reassurance to women who have cancer while pregnant that they can safely receive treatment during the second or third trimester with chemotherapy or radiation without compromising their unborn child. The study showed that children born to mothers who receive chemotherapy or radiation during pregnancy had no impairment in general health, cognition, or cardiac function compared with children born to healthy mothers, said lead investigator Frédéric Amant, MD, PhD, Department of Gynecologic Oncology, University Hospitals Leuven, Belgium.
Dr Amant presented the results at the 2015 European Cancer Congress; the study was simultaneously published online to coincide with his presentation (Amant F. N Engl J Med. 2015;373:1824-1834).
However, women in the first trimester should not undergo chemotherapy or radiation. Prematurity is associated with worse cognitive outcomes in general; however, in this study, cancer treatment during pregnancy resulted in no additive impairment in babies born prematurely.
According to Dr Amant, these findings mean that it is no longer necessary to induce preterm delivery so that cancer treatment can be initiated.
“These results show that preterm delivery, but not cancer treatment, is associated with worse outcomes. This suggests that we should no longer induce preterm delivery and that it is safe to start cancer treatment while a woman is pregnant, except during the first trimester,” Dr Amant told the audience.
“We hope that with these data we can convince more oncologists around the world to treat cancer during pregnancy and avoid preterm delivery.”
The multicenter, case-control study enrolled 129 children born to mothers who had cancer during pregnancy (prenatal exposure group) and matched them 1:1 to 129 controls who were born to healthy mothers after uncomplicated pregnancies and deliveries.
In the exposure group, 96 children were exposed to chemotherapy alone or in combination with other treatments, 11 to radiation alone or in combination, 13 to surgery alone, and 2 to other drug treatments. Of this group, 4 women had radiation and surgery, and 7 received chemotherapy and radiation; 14 of the women did not receive treatment until after delivery.
In the exposure group, 61% of the children were born preterm versus 8% in the general population. The number and type of congenital malformations were similar between cases and controls.
The investigators assessed the general health of offspring, cognitive outcomes, and cardiac morphology and function. All infants were tested at 18 months, and 48 infants were tested at 18 months and 36 months.
Birth weight was below the tenth percentile (defined as small for gestational age) in 28 (22%) infants in the prenatal exposure group, and in 19 (15.2%) infants in the control group, a difference that was not statistically significant. Looking more closely, the rates of “small for gestational age” were 25% in children exposed to chemotherapy and 36% in those exposed to radiotherapy, but 64% caught up in terms of weight at 18 months.
There was no difference between exposed infants and controls in general medical health, which reflected the incidence of medical problems and need for surgery and/or medical care.
Assessment of cognitive outcome at a median age of 22 months showed no significant differences in cognition between the exposure group and controls, and no differences related to the number of cycles or type of chemotherapy—anthracyclines, taxanes, and platinum derivatives—or to the estimated fetal dose of radiation.
Cardiac function was assessed at 36 months in 50 of 54 children in the prenatal exposure group using electrocardiography and echocardiography, with 47 children having sufficient data for evaluation. These children were compared with 47 matched controls for age and sex. No structural or functional cardiac abnormalities were seen in any of the exposed children, and there were no differences in cardiac measures between exposed children and controls.
Although heart function in the exposed babies was normal, Dr Amant recommended long-term monitoring for babies whose mothers received anthracyclines, which comprised a majority of women.
These findings, however, cannot be extrapolated to newer targeted agents, Dr Amant cautioned.