Colorectal cancer (CRC) is the third most common cancer globally, with approximately 1.9 million cases and 935,000 deaths reported in 2020. Incidence rates of CRC are increasing among adults born in and after the 1960s, which has led researchers to investigate the potential role of pregnancy-related exposures introduced during that time as risk factors. One such exposure is Bendectin, an anti-emetic medication prescribed during pregnancy in the 1960s that contained dicyclomine, an antispasmodic used to treat irritable bowel syndrome.
A recent study published in the Journal of the National Cancer Institute has shown that in-utero exposure to a specific drug prescribed to pregnant women in the 1960s, Bendectin, may be linked to an increased risk of colorectal cancer (CRC) in offspring. The study found that offspring exposed in utero to the drug had a significantly higher risk of CRC than unexposed offspring.CRC is the third most common cancer in the United States.
CRC incidence rates have steadily increased among adults born in and after the 1960s, implicating pregnancy-related exposures introduced as potential risk factors. Bendectin was an anti-emetic drug prescribed to pregnant women in the 1960s to treat nausea and vomiting. The drug was composed of doxylamine, pyridoxine, and dicyclomine. Dicyclomine, an antispasmodic used to treat irritable bowel syndrome, is the component of Bendectin that interests this study.
Data from the Child Health and Development Study, a multigenerational cohort that enrolled pregnant women in Oakland, California, between 1959 and 1966, were used to assess children’s risk of developing CRC following prenatal exposure to Bendectin. The study examined prescription medications from moms’ medical records to determine who received Bendectin during pregnancy. CRC diagnoses were then verified throughout the progeny’s adult years using a database connection to the California Cancer Registry.
According to research, around 5% of children (n = 1,014) were exposed to Bendectin while still in the womb. In contrast to children who were not exposed during pregnancy, those with a greater risk of developing CRC (aHR 3.38, 95% CI 1.69, 6.77). Bendectin-exposed children had a 30.8 (95% CI 15.9, 53.7) times greater incidence of CRC than non-exposed children, at a rate of 10.1 (95% CI 7.9, 12.8) per 100,000.
According to the study, dicyclomine, a component of the three-part Bendectin formulation used in the 1960s, may be responsible for the elevated risk of CRC in children exposed in utero. This work emphasizes the importance of more experimental research to explain these findings and identify danger sources.
It is important to note that Bendectin was voluntarily withdrawn from the market in the United States in 1983 due to concerns about its safety. Despite the drug being withdrawn over 30 years ago, this study highlights the potential long-term health effects of in-utero exposure to certain drugs. The study has important implications for both medical professionals and pregnant women.
Medical professionals may need to consider the potential long-term effects of certain drugs prescribed during pregnancy, even if they have been deemed safe. Pregnant women may also want to be more cautious about taking medication during pregnancy and discuss any potential risks with their healthcare provider.