Early-onset colorectal cancer incidence rates in the United States have nearly doubled between 1992 and 2013—up from 8.6 to 13.1 per 100,000 individuals—with most of that increase due to early-onset cancers of the rectum. A new study published by Archambault et al in JNCI Cancer Spectrum focused on investigating whether the risk factors associated with late-onset colorectal cancer were also relevant to early-onset disease and whether association patterns differed by anatomic subsite.

Researchers found that several nongenetic risk factors are linked with early-onset colorectal cancer, including not regularly using aspirin, greater intake of red meat, and lower educational attainment. In addition, researchers found both heavier alcohol use and alcohol abstinence were also associated with the development of early-onset colorectal cancer. The study’s findings provide an initial basis for targeted identification of those most at risk, which is imperative in mitigating the rising burden of this cancer, according to the study authors.

Study Methods

The researchers used data pooled from 13 population-based studies. They included 3,767 cases of colorectal cancer and 4,049 controls in people aged 50 and younger, and 23,437 cases of colorectal cancer and 35,311 controls in people aged 50 and older. Patient recruitment occurred across all the studies between the 1990s and the early 2010s.

The researchers used multivariable and multinomial logistic regression to estimate odds ratios and 95% confidence intervals to assess the association between risk factors and early-onset colorectal cancer and by anatomic subsite.

Results

The researchers found that early-onset colorectal cancer was associated with nonregular use of nonsteroidal anti-inflammatory drugs (odds ratio [OR] = 1.43, 95% confidence interval [CI] = 1.21–1.68), greater red meat intake (OR = 1.10, 95% CI = 1.04–1.16), lower educational attainment (OR = 1.10, 95% CI = 1.04–1.16), alcohol abstinence (OR = 1.23, 95% CI = 1.08–1.39), and heavier alcohol use (OR = 1.25, 95% CI = 1.04–1.50). No factors exhibited a greater excess in early-onset compared with late-onset colorectal disease.

Evaluating risks by anatomic subsite, the researchers found that lower total fiber intake was linked more strongly to rectal cancer (OR = 1.30, 95% CI =1.14–1.48) than colon cancer (OR = 1.14, 95% CI = 1.02–1.27; P = .04).

The researchers also found that several other colorectal risk factors trended toward an association with early-onset disease, including a history of diabetes, as well as lower folate, dietary fiber, and calcium intake. However, neither body mass index nor smoking were risk factors in the early-onset patients compared with the last-onset patients.

Clinical Relevance

“This first large-scale study of nongenetic risk factors for early-onset colorectal cancer is providing the initial basis for targeted identification of those most at risk, which is imperative in mitigating the rising burden of this disease,” said Richard B. Hayes, PhD, MPH, DDS, senior investigator for the study and Professor in the departments of Population Health and Environmental Medicine at NYU Langone Health, Grossman School of Medicine, in a statement.

Disclosure: Funding for this study was provided by the National Cancer Institute. For full disclosures of the study authors, visit academic.oup.com.