Is it safe to treat pregnant women with cancer when it comes to the health of both the mother and the fetus? That's a question that researchers with the International Network on Cancer, Infertility, and Pregnancy (INCIP) set out to answer nearly 2 decades ago.
"At that time, there was no evidence of the short- or long-term safety of cancer treatment during pregnancy, and pregnant women with cancer were advised to terminate their pregnancies or deliver prematurely to begin cancer treatment postpartum," Indra A. Van Assche, MSc, a PhD researcher in the Department of Development and Regeneration at KU Leuven, Belgium, told Oncology Times. "The determination of several mothers not to terminate pregnancy sparked interest in investigating the impact of cancer treatment during pregnancy on the development of the child," she added.
And now, thanks to those babies being born and they and their families agreeing to be part of this research, there is data available on how those prenatal cancer and cancer treatment exposures may have affected their development.
Since starting the research, INCIP researchers have published several papers, but a new one in a March 2023 issue of the Journal of Clinical Oncology (doi: 10.1200/JCO.22.02005) is the first of its size to look at a wide range of neurocognitive and behavioral outcomes. The group published another review paper on the same topic late last year in the journal Critical Reviews in Oncology/Hematology (2022; https://doi.org/10.1016/j.critrevonc.2022.103824).
"The data shows a reassuring neurocognitive development, as cancer treatment during pregnancy did not associate with any measures of cognition or behavior," Van Assche said. Though, she noted there were risks associated with children that were delivered prematurely. She also added that more work is needed and researchers are continuing to follow this patient cohort.
Study Details
The study was a multicenter cohort study that analyzed the long-term effects of prenatal exposure to cancer and cancer treatments on 9-year-old children. Participants included 151 children who were assessed via neurocognitive testing and parent-report behavioral questionnaires.
Of the children in the cohort, 109 were exposed to chemotherapy (only or in combination with other treatments), 18 were exposed to surgery only, 16 were exposed to radiotherapy, one was exposed to trastuzumab, and 16 were not exposed to oncologic treatments. The data showed that mean cognitive and behavioral outcomes were within normal ranges. Gestational age at birth was positively associated with cognitive test scores. However, there was no difference in cognitive test scores for the various cancer treatment types. Also, there were no associations between cognitive test scores and chemotherapeutic agent, exposure level, or timing during pregnancy.
"We hope that our newest report reassures oncologists and cancer care providers that cancer treatment is often possible during pregnancy, as children born from these pregnancies continue to develop normally into late childhood," Van Assche said. "Nevertheless, we still show an impact of preterm delivery, with children born preterm more at risk of having a lower IQ. Furthermore, children who had lost their mother before age 2 years may be at risk for having a lower IQ and needing more support, such as speech therapy or remedial teaching at school, although children whose mother had died were also more likely to have been born preterm."
She pointed out that, though the sample size of the study is large for this type of research, given that incidence of cancer during pregnancy is low overall, the group studied here is a heterogeneous one with many different treatments and cancers being represented. This makes it more difficult to focus on the impact of a specific treatment.
Reassuring Data
The bottom line for oncologists is a reassuring one, Van Assche repeated. "By showing a normal neurocognitive development towards the end of childhood, we can increase the confidence in treating pregnant patients with cancer by reassuring that oncological treatment is possible during pregnancy and that the aim should be for pregnant women to be treated as similarly as possible to non-pregnant women with the same cancer."
Morana Vojnic, MD, MBA, a medical oncologist at Lenox Hill Hospital in New York City, said the data is indeed reassuring. "Some cancer treatments can be safe for the fetus in pregnancy and not affect the child's development, based on the currently available data," she stated. "This gives more hope to mothers diagnosed with malignancies."
The data also reiterates the negative impact of preterm delivery and that it should be avoided, if possible, Van Assche said. "It may not be necessary to induce delivery preterm to start maternal oncological treatment postpartum if the same treatment can be administered during pregnancy. In some cases, the treatment plan may need to be altered or an alternative therapy may need to be administered depending on cancer type and timing," she said.
Sarah DiGiulio is a contributing writer.