Study examines which polyps lead to colon cancer

Researchers at Mayo Clinic are closer to learning why one colon polyp transforms to cancer while another seemingly identical polyp does not.

A colon polyp is a small clump of cells that forms on the lining of the colon. While most colon polyps are harmless, some can develop into colon cancer, which can be fatal if found too late.

“The molecular determinants that distinguish normal, benign polyps from those at risk for becoming cancer are unclear,” said Dr. Lisa Boardman, a gastroenterologist at Mayo Clinic. “In our paper, published in the journal Scientific Reports, we asked the question: Why does one polyp transform to cancer while another, that is clinically and histologically identical, does not?”

Boardman and her colleagues used next-generation sequencing techniques to molecularly characterize and compare colorectal polyps from Mayo Clinic patients that were associated with cancer with those from patients with benign polyps.

Boardman and her colleagues found that polyps adjacent to cancerous tissue exhibited distinct genetic alterations from polyps that remained cancer-free.

“We identified a panel of 124 genes that were differen- tially altered between polyps that were associated with cancer and polyps that did not progress to colorectal cancer,” she said. “These results serve as a foundational study showing that polyps with and without cancer exhibit distinct molecular signatures.”

Boardman said the ability to identify molecular features that predict whether a polyp will transform to cancer would be a major clinical step in individualizing the care of patients with polyps.