Surrogate tissue telomere length and cancer risk: shorter or longer?

Telomeres play a critical role in chromosome stability. Telomere length (TL) shortening is a risk factor for cancers. Measuring TL in surrogate tissues that can be easily collected may provide a potential tool for early detection of cancers. A number of studies on surrogate tissue TL and cancer risks have been conducted and results are inconsistent, including positive, negative, or null associations. In this article, we reviewed the published data on surrogate tissue TL in relation to cancer risks, discussed the possible reasons for the differences in the results and future directions and challenges for this line of research.