AACR Logo Telomeres small strips of DNA covering the ends of chromosomes seem to restrict chromosome tips from fraying during cell division. It is known that shortened telomeres elevate risk of cancer development. A recent study has discovered a possible association between long telomeres and an increased risk for colorectal cancer.

Experts noted that cancer people had longer telomeres as compared to healthy people. So there may be two different mechanisms affecting telomere length and that rising vulnerability to cancer. While conducting the study, peripheral blood leukocyte DNA telomere length of 772 patients diagnosed with microsatellite stable colorectal cancer was assessed. All the study subjects were younger than 60 years at diagnosis with no history of chemo-radiotherapy. The results were then compared to 1,660 nonrelated, age-matched, healthy controls.

As a result, patients with the longest telomeres, i.e. in the 95th percentile appeared 30 percent more likely to suffer from colorectal cancer than those in the 50th percentile. Scientists presume that overall individuals with the shortest and the longest telomere lengths are at an increased risk for colorectal cancer. There seem to be two distinct groups of colorectal cancer in young-onset patients. While the first group includes telomere shortening and a subset of young-onset colorectal cancer patients with probable accelerated aging. The other group may be a distinct subgroup of patients with longer telomeres. Further investigations will be undertaken to evaluate telomere maintenance genes in the peripheral blood DNA.

The study was presented at the American Association for Cancer Research special conference on Colorectal Cancer: Biology to Therapy.