Telomere length shortens cancer survival
medwireNews: Telomere length significantly predicts cancer survival but not the risk for developing malignancy, suggest results published in the Journal of the National Cancer Institute.
The study of 47,102 members of the Danish general population followed-up 3142 patients with a first cancer diagnosis for a maximum of 20 years, during which time 1730 patients died.
An analysis showed a significant and negative correlation between a decrease in telomere length and cancer survival, report Stig Bojesen (Copenhagen University Hospital, Herlev, Denmark) and co-authors.
The likelihood of early death in individuals with telomeres in the shortest quartile and decile, respectively, was 1.31 and 1.43 versus patients with the longest telomeres, after adjusting for age, gender, cancer stage, age at diagnosis, and other confounding factors.
The adjusted hazard ratio (HR) for early death was 1.12 per 1000 base pair decrease in telomere length, the researchers add. This HR was significant for patients who had been diagnosed with lung cancer (HR=1.27), melanoma (HR=1.67), leukemia (HR=1.57) and esophageal cancer (HR=0.42) but not other types of cancer studied.
"However, numbers were low, and future studies may determine whether these associations are real or represent chance findings," the team says.
By contrast, there was no significant difference in the risk for developing cancer between individuals in the shortest and longest quartiles and deciles for telomere length, after multivariate adjustment.
Bojesen et al note that this finding contradicts the results of two meta-analyses showing a significantly increased risk for cancer in individuals with the shortest versus longest telomeres.
Recognizing significant heterogeneity in the results included in these studies, the researchers hypothesize that the differences in findings could be due to differences in telomere measurement or statistical factors.
However, they note that their finding of telomere shortening of 19 base pairs per year is in line with previous results.
"It is plausible that cancer itself and/or cancer treatment can reduce telomere length, and thus the associations reported in both meta-analyses between short telomere length and cancer risk may be because of reverse causation," they suggest.
By Lynda Williams, Senior medwireNews Reporter