Colorectal cancer cells trigger a set of genes similar to those found in intestinal stem cells, scientists at the Institute for Research in Biomedicine have discovered.
They proposed that patients with colorectal cancer undergo genetic tests of their intestinal epithelium in order to predict a higher risk of relapse.
The results of the study, led by ICREA researcher Eduard Batlle, offer new possibilities for diagnosing and treating the disease.
Colon cancer is the second cause of death by cancer worldwide. Current treatment for the disease normally involves a combination of surgery and chemotherapy.
Most patients who are treated successfully go into remission, but nearly 40 percent relapse within months or years, when the cancer returns or metastasizes.
"This shows us that there are cells within the tumour that regenerate the disease, but we still know very little about the biological reasons why," said Batlle.
The study has uncovered a close relation between intestinal stem cells (non-specialised cells that generate all cells within the intestine) and colorectal cancer.
The researchers compared genes that are activated in cells from a healthy intestine - both stem cells and specialised cells - with the genes that are activated in tumour cells taken from patients.
"Our results show that patients with colon cancer have a set of genes activated that is very similar to the set activated in stem cells. The more genes they have activated in common, the more likely it is that the patient's cancer will spread and relapse.
These stem cell genes become activated in a subset of cells in the tumour, called "tumour stem cells".
When Batlle's team transplanted these cells into mice, tumours formed. Their results add to the growing hypothesis that cancer organizes itself hierarchically, in such a way that only specific cells, "tumour stem cells", are able to initiate and propagate the cancer.
The study was published online this week in Cell Stem Cell.