Evidence Points to Relative Safety of Chemotherapy in Pregnancy

Reassuring news for clinicians treating pregnant patients with cancer: chemotherapy does not appear to cause developmental problems in offspring. Dr Frederic Amant, assistant professor, staff gynecologic oncologist, and head of the scientific section of gynecologic oncology at Katholieke Universiteit in Leuven, Belgium, presented these findings at the 2011 European Multidisciplinary Cancer Congress.

Amant and colleagues recruited children between the ages of 18 months and 18 years old to participate in the study. The researchers evaluated 70 children for the current study; children’s health was monitored at birth and then every two years, on average. Some of the children were followed for as many as 18 years. In addition to general health, the participants were evaluated with neuropsychological testing to assess intelligence, verbal and nonverbal memory, attention, working memory, and behavior.

All of the mothers had cancer during their pregnancy. About half (51%) of the women were diagnosed with breast cancer; another 26% were diagnosed with hematologic cancers. Cervical cancer, ovarian cancer, and malignancies of the brain, skin, and colorectum were also represented. Mean gestational age at cancer diagnosis was 18.1 weeks; median gestational age for treatment was 17 weeks (range=12 to 37 weeks). Fifty percent of the women received chemotherapy, while another 38% received chemotherapy following surgery. In total, the cohort received 236 cycles of chemotherapy.

Almost 80% of the women received anthracyclines, which are important tools in treating breast and gynecological cancers. However, despite this exposure, Amant et al. found normal cardiac function at birth and no signs of congenital heart defects. In addition, the researchers noted growth, general health and development, and incidence and type of congenital malformations were similar to that found in the general population.

While the overall research did not show a link between developmental problems and chemotherapy, Amant and colleagues did notice a high rate of premature birth, with 66% of the children born before 40 weeks gestation. Average gestational age at birth was 35.7 weeks; intrauterine growth retardation was present in approximately 21% of the children.

Moreover, while cognitive development was in the normal range for the majority of the cohort, premature children more often fell below the normal parameters. However, Amant and colleagues could not determine if this was a direct result of the chemotherapy or a result of premature birth. “We can’t exclude the effects of chemotherapy in preterm children,” he explained in a press statement. “They do worse, we know that, but whether it’s the prematurity or the chemotherapy - that is an unanswered question.” 

It is also possible that twins fare less well than singleton births. The researchers found a pair of twins with significant neurodevelopmental delay; the twins were born at 32.5 weeks. Amant and colleagues could not determine what role chemotherapy played in that outcome.

“Our results so far suggest that children who were prenatally exposed to chemotherapy seem to do as well as children in the general population, and, that the treatment does not influence the development of mental processes or the functioning of the heart in the children we have followed for an average of 22 months,” Amant said in a statement to the press. “Therefore, although the role played by chemotherapy in the poor outcome of one of the twin pregnancies cannot be excluded, we believe these results do allow us to make a recommendation about chemotherapy in pregnancy: pregnant women with cancer do not need to delay their cancer treatment or terminate their pregnancy. The benefits of chemotherapy to the mothers outweigh any potential long-term harm to the children.

“However, it is important to prevent preterm birth if possible and continue pregnancy until at least 37 weeks, as the data suggest the children suffer more from prematurity than from prenatal chemotherapy,” he added. “Pregnant women who are receiving chemotherapy often have delivery induced from the moment the foetus is viable although not mature. Our results suggest this should be avoided.”

References:

EMCC News: Chemotherapy during pregnancy does not seem to cause developmental problems in children. European Society for Medical Oncology. September 27, 2011.