Research and Clinical Implications
Birth cohort CRC, including increasing EOCRC incidence, likely is driven by a range of influences, including demographic, lifestyle, early life, environmental, genetic, and somatic factors, as well as interactions among them, the authors noted. Examples within these broad categories include male sex, food insecurity, income inequality, diabetes, alcohol use, less healthy dietary patterns, in utero exposure to certain medications, and microbiome concerns such as early life antibiotic exposure or dysbiosis.
“From a research perspective, this means that we need to think about risk factors and mechanisms that are associated with birth cohorts, not just age at diagnosis,” Dr. Gupta said. “To date, most studies of changing epidemiology have not taken into account birth cohort, such as whether someone is Generation X or later versus pre-Baby Boomer.”
Although additional research is needed, the epidemiology changes have several immediate clinical implications, Dr. Gupta said. For those younger than 45, it is critical to raise awareness about the signs and symptoms of CRC, such as hematochezia, iron deficiency anemia, and unintentional weight loss, as well as family history.
For ages 45 and older, a major focus should be placed on increasing screening participation and follow-up after abnormal results, addressing disparities in screening participation, and optimizing screening quality.
In addition, as CRC incidence continues to increase, health systems and policymakers should ensure every patient has access to guideline-appropriate care and innovative clinical trials, the authors wrote. This access may be particularly important to address the increasing burden of rectal cancer, as treatment approaches rapidly evolve toward more effective therapies, such as neoadjuvant chemotherapy and radiation prior to surgery, and with less-morbid treatments on the horizon, they added.
‘An Interesting Concept’
“Birth cohort CRC is an interesting concept that allows people to think of their CRC risk according to their birth cohort in addition to age,” Shuji Ogino, MD, PhD, chief of the Molecular Pathological Epidemiology program at Brigham & Women’s Hospital, Boston, Massachusetts, told this news organization.
Dr. Ogino, who wasn’t involved with this study, serves as a member of the cancer immunology and cancer epidemiology programs at the Dana-Farber Harvard Cancer Center. In studies of EOCRC, he and colleagues have found various biogeographical and pathogenic trends across age groups.
“More research is needed to disentangle the complex etiologies of birth cohort CRC and early-onset CRC,” Dr. Ogino said. “Tumor cells and tissues have certain past and ongoing pathological marks, which we can detect to better understand birth cohort CRC and early-onset CRC.”
The study was funded by several National Institutes of Health/National Cancer Institute grants. Dr. Gupta disclosed consulting for Geneoscopy, Guardant Health, Universal Diagnostics, InterVenn Bio, and CellMax. Another author reported consulting for Freenome, Exact Sciences, Medtronic, and Geneoscopy. Dr. Ogino reported no relevant financial disclosures.
A version of this article appeared on Medscape.com .