Colorectal cancer, traditionally diagnosed in individuals over 50, is increasingly being found in younger people, with a notable impact on racial and ethnic minorities. A recent study published in Clinical Epigenetics by researchers from Baylor College of Medicine, University of California at Irvine, and Ben Taub Hospital highlights unique molecular features of early-onset colorectal cancer.
Dr. Karen Riggins from Baylor expressed the concern observed in clinical settings: "In the clinic, we not only see more young people being diagnosed with an older person’s disease, but most are minority patients who present with an advanced condition and poor prognosis." This led to a deeper investigation into the differences between early and late-onset forms of the disease.
Co-corresponding author Dr. Lanlan Shen pointed out that "there is evidence supporting that the early and late-onset forms of colorectal cancer are different." The research revealed that early onset cancer predominantly affects the left side of the colon and is more aggressive than its late-onset counterpart. It was noted that 80% of these cases do not have identifiable genetic mutations, particularly affecting Hispanics and African Americans with lower survival rates compared to Caucasians.
The study explored environmental risk factors like diet, stress, and gut microbiome as potential contributors to these disparities. Researchers focused on epigenetic modifications—changes in DNA methylation—that could lead to cancer development without altering DNA sequences. Dr. Shen explained that "dysregulation of DNA methylation plays an important role in colorectal cancer."
Significant findings included epigenetic alterations specific to racial/ethnic minorities but absent in Caucasian patients from the Cancer Genome Atlas (TCGA). These included changes in genes such as MFAP2, APOL3 11, and RNASEL.
Dr. Riggins highlighted the importance of this study: “Although preliminary, this study is important because it generates high-quality whole genome information on racial and ethnic minority patients who are severely underrepresented in research studies.” The lack of representation presents challenges in understanding diseases like early onset colorectal cancer.
Shen added insights into potential treatments: “Our exploratory findings in this cohort highlight epigenetic mechanisms underlying the emergence of early onset colorectal cancer. This is promising because it suggests that treatments directed at restoring methylation markers associated with the disease might have therapeutic value.”
The study involved contributions from several researchers including Jason Sheng Li, Li Yang, Chaorong Chen among others affiliated with Baylor College of Medicine, University of California at Irvine, and Ben Taub Hospital.
The research received support through donations from the Walter Worth family and grants from institutions such as the National Institutes of Health (NIH) and the US Department of Agriculture.
