Skip to main content
Grant Details

Grant Number: 5R01CA242558-04 Interpret this number
Primary Investigator: Murphy, Caitlin
Organization: University Of Texas Hlth Sci Ctr Houston
Project Title: Early Life Exposures and Risk of Young-Onset Colorectal Cancer
Fiscal Year: 2022


Project Summary In contrast to dramatic declines in older populations, the incidence of colorectal cancer (CRC) has nearly doubled among younger adults since the early 1990s. Mechanisms contributing to the rising incidence of young‐onset CRC (age <50 years) have puzzled researchers for years, and to date, family history of polyps or CRC remains the only clearly established risk factor. Our prior work shows a strong birth cohort effect, whereby incidence increased markedly among persons born in or after the 1960s. Higher incidence of young‐ onset CRC among this birth cohort (approximately Generation X) implicates environmental exposures in early life. Antibiotics, cesarean delivery, birth weight, and childhood obesity – increasingly prevalent in early life – may contribute to rising incidence of young‐onset CRC. Prevalence of these environmental exposures exploded among persons born after 1960. For example, broad‐spectrum antibiotic use nearly tripled among children of the 1960s, and cesarean deliveries increased from 5% of births in 1960 to more than 30% in 2015. Mounting evidence suggests these environmental exposures alter gut microbiota, and gut microbiota may act as a key promoter of carcinogenesis, thus, mediating the relationship of environmental exposures with CRC. In the proposed project, we will generate timely evidence concerning effects of environmental exposures in early life on risk of young‐onset CRC and advance our understanding of causal mechanisms contributing to this disease. We will leverage existing data on 19,044 children enrolled in the Child Health and Development Studies (CHDS), and for whom we can ascertain young‐onset CRC diagnoses with high‐quality cancer registry data. CHDS comprises a diverse, population‐based cohort of children born in the 1960s to women receiving prenatal care in the Kaiser Foundation Health Plan (Oakland, California). CHDS collected information on prenatal visits, labor and delivery, and pediatric visits. These data do no rely on parents' or study participants' memory but excellent capture of individual‐level risk factors collected prospectively from medical records. We will append these well‐characterized data with information on family history and germline mutations by re‐ contacting CHDS participants for consent to obtain biospecimens. Our innovative use of data from an existing cohort study, combined with genomic data collected in the present day, will provide a more complete picture of young‐onset CRC than has been previously possible. We will: 1) Estimate the association of antibiotics (prenatal, perinatal, childhood), cesarean delivery, birth weight, and childhood obesity and young‐onset CRC; 2) Explore whether the association between these early life exposures and young‐onset CRC differs among those with and without a family history and/or germline mutation; and 3) Estimate the population impact of early life exposures on risk of young‐onset CRC, by synthesizing effect estimates with prevalence of early life exposures derived from population‐based surveys. By leveraging data on early life exposures from CHDS, we will generate new evidence that may ultimately be applied to CRC prevention and risk‐reduction strategies.


No Increase in Colorectal Cancer Screening in 2019 After American Cancer Society Recommends Starting Screening at Age 45.
Authors: Liu P.H. , Singal A.G. , Murphy C.C. .
Source: Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association, 2023 Jul; 21(7), p. 1947-1949.e2.
EPub date: 2022-06-11.
PMID: 35700888
Related Citations

Declines in Colorectal Cancer Incidence and Mortality Rates Slow Among Older Adults.
Authors: Murphy C.C. , Lee J.K. , Liang P.S. , May F.P. , Zaki T.A. .
Source: Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association, 2023-06-10; , .
EPub date: 2023-06-10.
PMID: 37308035
Related Citations

In utero exposure to antiemetic and risk of adult-onset colorectal cancer.
Authors: Murphy C.C. , Cirillo P.M. , Krigbaum N.Y. , Singal A.G. , Cohn B.A. .
Source: JNCI cancer spectrum, 2023-03-01; 7(2), .
PMID: 36895101
Related Citations

Racial and Ethnic Disparities in Early-Onset Colorectal Cancer Survival.
Authors: Zaki T.A. , Liang P.S. , May F.P. , Murphy C.C. .
Source: Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association, 2023 Feb; 21(2), p. 497-506.e3.
EPub date: 2022-06-16.
PMID: 35716905
Related Citations

In-utero exposure to antibiotics and risk of colorectal cancer in a prospective cohort of 18 000 adult offspring.
Authors: Murphy C.C. , Cirillo P.M. , Krigbaum N.Y. , Singal A.G. , Jones D.P. , Zaki T. , Cohn B.A. .
Source: International journal of epidemiology, 2023-01-24; , .
EPub date: 2023-01-24.
PMID: 36692207
Related Citations

Persistent Disparities in Colorectal Cancer Screening: A Tell-Tale Sign for Implementing New Guidelines in Younger Adults.
Authors: Liu P.H. , Sanford N.N. , Liang P.S. , Singal A.G. , Murphy C.C. .
Source: Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 2022-09-02; 31(9), p. 1701-1709.
PMID: 35765830
Related Citations

Early Life: An Important Window of Susceptibility for Colorectal Cancer.
Authors: Murphy C.C. , Cohn B.A. .
Source: Gastroenterology, 2022 Aug; 163(2), p. 532-533.
EPub date: 2022-01-07.
PMID: 35007514
Related Citations

Maternal obesity, pregnancy weight gain, and birth weight and risk of colorectal cancer.
Authors: Murphy C.C. , Cirillo P.M. , Krigbaum N.Y. , Singal A.G. , Lee M. , Zaki T. , Burstein E. , Cohn B.A. .
Source: Gut, 2022 Jul; 71(7), p. 1332-1339.
EPub date: 2021-08-24.
PMID: 34429385
Related Citations

Colorectal Cancer in Younger Adults.
Authors: Dharwadkar P. , Zaki T.A. , Murphy C.C. .
Source: Hematology/oncology clinics of North America, 2022 Jun; 36(3), p. 449-470.
EPub date: 2022-05-13.
PMID: 35577711
Related Citations

Increasing Incidence Rates of Colorectal Cancer at Ages 50-54 Years.
Authors: Zaki T.A. , Singal A.G. , May F.P. , Murphy C.C. .
Source: Gastroenterology, 2022 Mar; 162(3), p. 964-965.e3.
EPub date: 2021-10-29.
PMID: 34757141
Related Citations

In utero exposure to 17α-hydroxyprogesterone caproate and risk of cancer in offspring.
Authors: Murphy C.C. , Cirillo P.M. , Krigbaum N.Y. , Cohn B.A. .
Source: American journal of obstetrics and gynecology, 2022 Jan; 226(1), p. 132.e1-132.e14.
EPub date: 2021-11-09.
PMID: 34767803
Related Citations

Rising Early-onset Colorectal Cancer Incidence Is Not an Artifact of Increased Screening Colonoscopy Use in a Large, Diverse Healthcare System.
Authors: Lee J.K. , Merchant S.A. , Jensen C.D. , Murphy C.C. , Udaltsova N. , Corley D.A. .
Source: Gastroenterology, 2022 Jan; 162(1), p. 325-327.e3.
EPub date: 2021-09-20.
PMID: 34555382
Related Citations

Epidemiology and Mechanisms of the Increasing Incidence of Colon and Rectal Cancers in Young Adults.
Authors: Stoffel E.M. , Murphy C.C. .
Source: Gastroenterology, 2020 Jan; 158(2), p. 341-353.
EPub date: 2019-08-05.
PMID: 31394082
Related Citations

Back to Top