Researchers at the University of Kentucky analyzed different factors that could explain the high mortality rates of colorectal cancer in Appalachian Kentucky.

The interdisciplinary team of researchers led by Avinash Bhakta, M.D., a colorectal surgeon at the UK Markey Cancer Center, focused on analyzing samples from patients diagnosed with colon adenocarcinoma and looking at characteristics that could explain disparities in cancer outcomes in Kentucky.

The study, “Survival Disparity and the Unique Genomic and Microbiome Profiles of Colon Cancer in Appalachian Kentucky,” was recently published in the Journal of American College of Surgeons.

Even though Appalachian Kentucky is a rural region with significant economic distress, the authors said that “the differences in colorectal cancer incidence and outcomes cannot be entirely attributed to resource scarcity.”

The study investigated differences in the tumors from Appalachian and non-Appalachian patients.

“Our study is the first to characterize the impact of differential gene expression and tumor microbiome in Appalachian Kentucky patients with colon cancer,” said Hannah McDonald, M.D., Ph.D., a fourth-year general surgery resident in the UK College of Medicine.

The team found some genes that were mutated more frequently in the Appalachian population compared to non-Appalachian, and that some cancer-promoting genes were more abundant in the Appalachian cohort. These differences didn’t have an impact on the survival of the patients.

Additionally, the researchers examined the tumor microbiome—a collection of fungi, virus and bacteria present in the tumors. For this study, they focused on bacterial species. The group of Appalachian patients had more pathogenic and less beneficial bacteria compared to their non-Appalachian counterparts.

Upon further investigation, the team found that seven of those identified bacterial species had an impact on the survival of the patients.

“Our results demonstrated differences in microbiota between the two groups, suggesting that a unique tumor microbiome could be contributing to poor outcomes,” said Bhakta.

These findings are not only groundbreaking and unique in the state, but they can also contribute to the development of new strategies to treat colon cancer patients.

Researchers said this study suggests that modifying the cancer-promoting microbiome with probiotic or antibiotic therapy could be a possibility in the future, but further studies are needed.