CHICAGO, Oct. 1 (Xinhua) -- Changes in telomere length over time may be an indicator of oncoming cancer, researchers at Northwestern University (NU) found.
In a retrospective study, the researchers looked at telomere length over a 13-year period in almost 800 people, 135 of whom eventually received a cancer diagnosis. Telomeres for everyone shortened each year for several years, but among those who were eventually diagnosed with cancer, telomeres shortened much faster, appearing 15 years older in some cases than those who were not subsequently diagnosed with cancer.
More surprisingly, the telomeres of people who eventually received a cancer diagnosis stopped shortening about three to four years before their diagnosis, while the telomeres of people who were not diagnosed with cancer continued to shorten.
The research is the first reporting trajectory of telomere changes over many years in people who eventually develop cancer. It is also believed to be the first to look at telomere length at more than one point before diagnosis.
This is significant, because cancer treatment itself can change telomere length, making it difficult to know to what extent telomere length has been impacted by cancer itself, said Lifang Hou, a professor of preventive medicine and chief of cancer epidemiology and prevention at NU Feinberg School of Medicine.
Hou envisions a day when routine, annual lab testing measures a patient's telomere length alongside conventional metrics like blood cell count and cholesterol level. If their telomere length has changed significantly from one year to the next, the doctor would follow up to see what's changed in the patient's life: their diet, exercise routine, stress level, etc.
Telomeres are the protective end caps at each of human chromosomes. Telomeres typically get shorter as people age, but environmental factors, say diet, smoking, exposure to pesticides, air pollution and heavy metals, can also contribute to premature shortening.
