Research led by Weill Cornell Medicine provides new evidence that most colorectal cancers begin with the loss of intestinal stem cells, even before cancer-causing genetic alterations appear. The results, published on May 29 in Developmental Cell, overturn the prevailing theory for colorectal tumor initiation and suggest new ways to diagnose the disease before it has a chance to become established. "Colorectal cancer is very, very heterogeneous, which has made it difficult for many years to classify these tumors in order to inform therapy," said senior author Dr.
Jorge Moscat, Homer T. Hirst III Professor of Oncology in Pathology and Vice-Chair for Cell and Cancer Pathobiology in the Department of Pathology and Laboratory Medicine at Weill Cornell Medicine. This heterogeneity, the diverse characteristics of colorectal tumor cells in different patients and also within the same tumor, makes treatment particularly challenging.
Colorectal tumors can arise from two types of pre-cancerous polyps: conventional adenomas and serrated adenomas. Conventional adenomas were thought to develop from mutations in the normal stem cells that lie at the bottoms of intestinal crypts, pit-like structures in the lining of the intestine. Serrated adenomas, on the other hand, are associated with a different type of stem-like cell with fetal characteristics that appears mysteriously at the tops of the crypts.
Scientists in the field have described these apparently distinct tumor-forming processes as ".
