Telomere Biomarker Blood Test Predicts Cancer Years In Advance

Telomeres are sequences of DNA on the ends of chromosomes that stop them fraying and losing their integrity, but they gradually shorten as one ages and by the time one grow up they are half the length they were when a person was born, then they halve again as they enter old age.

Telomeres shorten every time a cell divides, which is why they get progressively shorter as they age and if the telomeres of a cell become too short, they can cause the cell to become faulty, and normally the cell self-destructs. However since cancer cells divide more rapidly than normal cells, the question arises why they do not self-destruct when their telomeres become dangerously short.

Scientists at Northwestern University Feinberg School of Medicine (Chicago, IL, USA) measured telomere length several times over a 13-year period in 792 people. One hundred and thirty-five of the participants eventually developed various cancers, including leukemia, and prostate, skin and lung cancer. The telomeres of the participants who were later diagnosed with cancer aged much faster, that is they shortened more rapidly, in the first few years. In the participants who developed cancer, the telomeres looked as much as 15 years older than those of the participants who did not develop cancer. But what was surprising was that the accelerated aging stopped three to four years before cancer diagnosis.

The authors concluded that relative to approaching cancer diagnosis, age-adjusted blood telomere length (BTL) attrition decelerated in cancer cases, ultimately yielding significantly elongated BTL and suggesting that critical BTL shortening may contribute to cancer initiation which then, in turn, activates telomere maintenance mechanisms to compensate and further promote cancer. These results may help explain the inconsistent results of previous studies and provide more insight into using BTL as an early detection biomarker of cancer.

Lifang Hou, MD, PhD, the lead study author, said, “Understanding this pattern of telomere growth may mean it can be a predictive biomarker for cancer. Because we saw a strong relationship in the pattern across a wide variety of cancers, with the right testing these procedures could be used to eventually diagnose a wide variety of cancers.” The study was published online on the April 30, 2015, in the journal EbioMedicine.

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Northwestern University Feinberg School of Medicine