Researchers may have identified an association between certain types of childhood cancers and cannabis use among pregnant patients, according to a recent study published by Wimberly et al in Cancer Epidemiology, Biomarkers & Prevention. The findings add specificity to the potential harms of drug and alcohol use during pregnancy.
Background
The risks of drug use, smoking, and drinking alcohol during pregnancy have been widely accepted. However, the use of cannabis—often as a remedy for severe morning sickness and nausea—has recently increased.
“Alcohol and tobacco use during pregnancy have declined, but gestational cannabis use has risen in the last decade,” explained senior study author Kyle Walsh, PhD, Associate Professor in the Department of Neurosurgery, Pathology, Pediatrics, and Population Health Sciences at the Duke University School of Medicine. “The psychoactive compounds of cannabis are capable of crossing the placental barrier and may interfere with normal neuronal development in the fetal brain. We examined 15 different types of childhood cancer and identified an association that was quite specific to cancers of the central nervous system [CNS],” he continued.
Study Methods and Results
In the recent study, the researchers surveyed the parents of pediatric patients diagnosed with cancer prior to the age of 18 from 3,145 families—of which, 92% identified as the biological mothers of the patients. The respondents were asked to answer questions regarding the maternal use of tobacco, alcohol, and/or illicit drugs during pregnancy.
The researchers found that about 14% of the families reported the gestational use of tobacco products, 4% of them reported using illicit drugs such as marijuana or cocaine, and 2% of them reported drinking greater than a moderate amount of alcohol. Although cannabis use was not analyzed separately, the survey specifically referenced marijuana as a category of illicit drug. Further, marijuana has been documented as the most commonly used illicit substance during pregnancy.
Prenatal illicit drug use was associated with an increased prevalence of CNS tumors—including medulloblastomas, supratentorial primitive neuroectodermal tumors, as well as retinoblastomas. Additionally, the researchers discovered that moderate to heavy alcohol consumption was strongly associated with an elevated risk of non-Hodgkin lymphoma, and maternal tobacco smoking during pregnancy was associated with a reduced newborn birthweight, but not with an elevated risk of specific cancer types.
Conclusions
“We hope that our findings can promote increased provider-patient dialogues about the potential effects of prenatal substance use, and cannabis use in particular. This has implications for public health messaging. We also stress the need for further research into the risk–benefit profile of cannabis use among expectant mothers,” Dr. Walsh emphasized.
The researchers concluded that the risks of gestational substance use should be weighed appropriately, with different considerations for patients experiencing severe morning sickness vs those who use cannabis recreationally.
Disclosure: The research in this study was funded by Alex’s Lemonade Stand Foundation, the Tobacco-Related Disease Research Program of California, and the National Cancer Institute. For full disclosures of the study authors, visit aacrjournals.org.
