Gestational biomarkers of daughter's breast cancer in the Child Health and Development Studies

In utero exposure to antihistamines and risk of hepatocellular carcinoma in a multigenerational cohort

BACKGROUND

Growing evidence suggests that liver disease originates in early life. Antihistamines cross the placenta and are frequently prescribed to pregnant women to treat nausea and vomiting, as well as allergy and asthma symptoms. Exposure to antihistamines in utero may impact the developing liver by reprogramming or inducing epigenetic changes in fetal hepatocytes.

METHODS

We examined in utero exposure to antihistamines and the risk of HCC in the Child Health and Development Studies, a multigenerational cohort that enrolled pregnant women in the East Bay, CA, between 1959 and 1966 (n=14,507 mothers and 18,751 liveborn offspring). We reviewed mothers' medical records to identify those prescribed antihistamines during pregnancy, and diagnoses of HCC in adult (age ≥18 y) offspring were identified by linkage with a population-based cancer registry. Cox proportional hazard models were used to estimate adjusted hazard ratios, with follow-up accrued from birth through cancer diagnosis, death, or last contact.

RESULTS

About 15% of offspring (n=2759 of 18,751) were exposed in utero to antihistamines. Chlorpheniramine (51.8%) and diphenhydramine (15.4%) were the 2 most commonly prescribed antihistamines. Any in utero exposure was not associated with HCC (adjusted hazard ratio: 2.76, 95% CI: 0.70, 10.89), but the association differed by timing of exposure. Offspring exposed to antihistamines in the first or second trimester had a higher risk of HCC compared to offspring not exposed (adjusted hazard ratio: 4.64, 95% CI: 1.21, 17.78). Similarly, incidence rates were 4.3 per 100,000 (95% CI: 0.9, 12.6) for offspring exposed in the first or second trimester compared to 1.0 per 100,000 (95% CI: 0.3, 2.1) for offspring not exposed.

CONCLUSIONS

In utero exposure to antihistamines in early pregnancy may increase the risk of HCC in adulthood.

Maternal obesity, pregnancy weight gain, and birth weight and risk of colorectal cancer

OBJECTIVE

Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide. Obesity is a well-established risk factor for CRC, and fetal or developmental origins of obesity may underlie its effect on cancer in adulthood. We examined associations of maternal obesity, pregnancy weight gain, and birth weight and CRC in adult offspring.

DESIGN

The Child Health and Development Studies is a prospective cohort of women receiving prenatal care between 1959 and 1966 in Oakland, California (N=18 751 live births among 14 507 mothers). Clinical information was abstracted from mothers' medical records 6 months prior to pregnancy through delivery. Diagnoses of CRC in adult (age ≥18 years) offspring were ascertained through 2019 by linkage with the California Cancer Registry. We used Cox proportional hazards models to estimate adjusted HR (aHR); we examined effect measure modification using single-referent models to estimate the relative excess risk due to interaction (RERI).

RESULTS

68 offspring were diagnosed with CRC over 738 048 person-years of follow-up, and half (48.5%) were diagnosed younger than age 50 years. Maternal obesity (≥30 kg/m²) increased the risk of CRC in offspring (aHR 2.51, 95% CI 1.05 to 6.02). Total weight gain modified the association of rate of early weight gain (RERI -4.37, 95% CI -9.49 to 0.76), suggesting discordant growth from early to late pregnancy increases risk. There was an elevated association with birth weight (≥4000 g: aHR 1.95, 95% CI 0.8 to 4.38).

CONCLUSION

Our results suggest that in utero events are important risk factors for CRC and may contribute to increasing incidence rates in younger adults.

A vision for exposome epidemiology: The pregnancy exposome in relation to breast cancer in the Child Health and Development Studies

Etiology of complex diseases, such as breast cancer, involves multiple genetic, behavioral and environmental factors. Gene sequencing enabled detection of genetic risks with relatively small effect size, and high-resolution metabolomics (HRM) to provide omics level data for exposures is poised to do the same for environmental epidemiology. Coupling HRM to the Child Health and Development Studies (CHDS) cohort combines two unique resources to create a prototype for exposome epidemiology, in which omics scale measures of exposure are used for study of distribution and determinants of health and disease. Using this approach, exposures and biologic responses during pregnancy have been linked to breast cancer in the CHDS. With improved chemical coverage and extension to larger populations and other disease processes, development of exposome epidemiology portends discovery of new disease-associated environment factors with small effect size as well as new capabilities to disentangle these from behavioral and other risk factors.