Baby Boomers and Birth Certificates: Early-Life Socioeconomic Status and Cancer Risk in Adulthood

Abstract

BACKGROUND Early life socioeconomic status (SES) may play a role in cancer risk in adulthood. However, measuring SES retrospectively presents challenges. Parental occupation on the birth certificate is a novel method of ascertaining early-life SES that has not been applied in cancer epidemiology. METHODS For a Baby-Boom cohort born in 1945–1959 in two Utah counties, individual-level Nam-Powers SES (Np-SES) was derived from parental industry/occupation reported on birth certificates. Neighborhood SES was estimated from average household income of census tract at birth. Cancer incidence was determined by linkage to Utah Cancer Registry records through the Utah Population Database. Hazard ratios (HR) for cancer risk by SES quartile were estimated using Cox proportional hazards regression. RESULTS Females with low Np-SES at birth had lower risk of breast cancer compared to those in the highest Np-SES group (HRQ1/Q4=0.83 95% CI: 0.72–0.97; HRQ2/Q4=0.81 95% CI: 0.69–0.96). Np-SES was inversely associated with melanoma (HRQ1/Q4=0.81 95% CI: 0.67–0.98) and prostate cancer (HRQ1/Q4=0.70 95% CI: 0.56–0.88). Women born into lower SES neighborhoods had significantly increased risk for invasive cervical cancer (HRQ1/Q4=1.44 95% CI: 1.12–1.85; HRQ2/Q4=1.33 95% CI: 1.04–1.72). Neighborhood SES had similar effects for melanoma and prostate cancers, but was not associated with female breast cancer. We found no association with SES for pancreas, lung, and colon and rectal cancers. CONCLUSION Individual SES derived from parental occupation at birth was associated with altered risk for several cancer sites. IMPACT This novel methodology can contribute to improved understanding of the role of early-life SES in affecting cancer risk.

Opportunities for life course research through the integration of data across Clinical and Translational Research Institutes

“…Synthesizing EHRs with data from external sources, such as population databases, biomonitors and environmental exposure data, would allow for investigations into the immediate and latent effects of risk factors over all ages. For example, individual level birth certificate and death certificate data can be linked to existing cohorts to increase the breadth and quality of measures relating to early life exposures [15, 19–21]. Combining these records also allows researchers to investigate dynamic health outcomes, such as how the relationship between changes in weight during mid-life affects later life disability [22] or how pregnancy outcomes affect trajectories of chronic conditions after the age of 65 [23].…”

The Utah Population Database. The Legacy of Four Decades of Demographic Research

“…Topics highlighted here are, quite simply, key selected examples of demographic interest but there are certainly many others. We note that other cross-cutting topics include studies that are spatially oriented (Smith et al, 2011;Stroup et al, 2017;Zick et al, 2009) as well as less-studied family formation topics such as those investigating step-children (Schacht, Meeks, Fraser, & Smith, 2021). The range of possible topics is considerable and in cases where the event is rare (e.g., extreme longevity, very young fertility) or is likely to vary by context (e.g., different centuries or nations), the size and breadth of UPDB lends itself to comparative analyses (e.g., Dillon et al, 2020;Dribe et al, 2017;Gagnon et al, 2009;.…”

“…UPDB has devoted resources to enhance the ability of investigators to test spatially-oriented hypotheses linked to health and demographic outcomes. Geo-referencing spatial data in order to locate individuals and their relatives and neighbors over decades has been a focus of UPDB (Leiser et al, 2020;Stroup et al, 2017). The challenge is to link persons to an area with comparable precision subject to data constraints.…”

Early-Life Risk Factors for Breast Cancer – Prospective Follow-up in the Northern Finland Birth Cohort 1966

“…Higher education level has been associated with higher incidence of breast cancer which may be explained by reproductive factors such as giving birth fewer times and more frequent use of hormone therapy and alcohol (23,24). Only a few studies have addressed the impact of individuals' early-life socioeconomic backgrounds, for example via parental education and occupation characteristics, on breast cancer risk in offspring in adult life (25,26). Although multiple risk factors for breast cancer have been determined, the role of antenatal period and birth in breast cancer in adult life is less studied.…”