Researchers Find Link Between Father's Occupation and Increased Risk of Colorectal Cancer in Offspring
A new study from UTHealth Houston School of Public Health and Child Health and Development Studies at the Public Health Institute (PHI) has found that children whose fathers worked in craft, operative, service or labor occupations experienced higher incidence rates of developing colorectal cancer later in life. The research highlights a potentially critical link between paternal occupational exposures and the long-term health of offspring.
Published in the Journal of the National Cancer Institute, the findings contribute to growing research suggesting that cancer risks may be transmitted across generations, including through the paternal line. The study was led by Caitlin Murphy, PhD, associate professor in the Department of Health Promotion & Behavioral Sciences, in collaboration with the PHI.
The team discovered that children whose fathers worked in crafts, operative, or service and labor jobs had a colorectal cancer diagnosis rate of 15.7. In contrast, children of fathers employed in professional, technical, or managerial occupations had a significantly lower incidence rate of 6.84.
“Our findings underscore the importance of research on environmental determinants of colorectal cancer, including environmental chemicals and occupational hazards,” said Murphy. Understanding the negative effects of these determinants has the potential to alter health outcomes for persons now aging into cancer risk. “Cancer-related risks may be lessened for future generations by identifying harmful exposures currently experienced by reproductive-age men.”
Researchers evaluated data from the long-running Child Health and Development Studies (CHDS), a unique multi-generational cohort established more than 60 years ago. Using CHDS data, researchers were able to track trends across 20,000 pregnancies and the families’ resulting offspring, including mothers, fathers, and now-adult offspring. Findings showed colorectal cancer incidence rates in offspring from the study were significantly higher in adults whose fathers worked in higher-risk occupations, such as mechanics, spray painters and welders. These jobs often involve exposure to hazards known to have established health risks.
“Research shows that environmental exposures to certain chemicals can harm our health—on the individual, community and generational levels,” said Barbara Cohn, PhD, study co-author and director of PHI’s CHDS. “This study shows that a father’s occupation is associated with certain chemical exposures which could impact their children’s risk of colorectal cancer through potential changes induced at conception or continued exposures in childhood—adding to a growing body of CHDS research that supports the idea that prenatal exposures can impact colorectal cancer risk.”
Investigators also used the California Cancer Registry to identify colorectal cancer cases among the children as they reached adulthood, linking cases to the occupational histories of fathers. Through this analysis, the team found compelling evidence of paternal exposures playing a significant role in shaping cancer risks in children.
“We don’t yet know the exact reason for this higher risk, but we believe it may be related to harmful occupational hazards,” Murphy stated. “There were not many regulations in the 1960s to protect against hazards, and fathers’ exposure near the time of conception may contribute to health risks in their offspring.”
Rising rates of early onset colorectal cancer pose a serious, significant risk to populations around the world—so much so that the recommended age for initial screening has been lowered from 50 to 45 by the American Cancer Society and other leading medical institutions. The National Cancer Institute estimates that 154,270 new cases of colorectal cancer are expected to be diagnosed in 2025.
People born in the 1960s, such as the offspring in the CHDS, represent birth cohorts who have experienced colorectal cancer at younger ages. Data shows that younger adults are particularly at risk: Though current numbers are still relatively low, projections estimate that by 2030, colorectal cancer will become the leading cause of cancer-related deaths for adults under 50.
“This study adds to the foundation for better understanding why rates of colorectal cancer are rising,” said Cohn. “By building on this research, we may be able to identify actionable biomarkers, just as scientists have done with cholesterol for heart disease — giving us critical new tools for assessing risk and advancing prevention strategies, helping individuals, industry leaders, medical professionals and policymakers better protect current and future generations from potential environmental exposures associated with generational colorectal cancer risk.”
This publication adds to growing evidence that health risks can be passed down to children of mothers and fathers that may have experienced harmful environmental exposures before or during pregnancies.
About Child Health and Development Studies
The Child Health and Development Studies (CHDS) investigates how health and disease are passed on between generations—not only genetically, but also through social, personal, and environmental surroundings. Studies spanning over 60 years enable CHDS scientists to study health across generations and seek ways to prevent disease early in life. CHDS is a program at the Public Health Institute. Learn more: https://www.chdstudies.org/
About the Public Health Institute
The Public Health Institute (PHI) and its programs improve health, equity, and wellness by discovering new research, strengthening key partnerships and programs, and advancing sound public health policies. Our hundreds of programs have impacted millions of people, creating an architecture that will continue to impact communities for generations to come. Learn more: www.phi.org