New test can predict cancer up to 13 years before disease develops
People who develop cancer have shorter telomeres, the caps at the end of chromosomes which protect the DNA
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Telomeres sit at the end of chromosomes like the caps on shoelaces to prevent DNA from fraying
A new test which can predict with 100 per
cent accuracy whether a person will develop cancer up to 13 years in
the future, has been devised by scientists.
Harvard and Northwestern University discovered that tiny but
significant changes are already happening in the body more than a decade
before cancer is diagnosed.
They
found that the protective caps on the ends of chromosomes, which prevent
DNA damage, had significantly more wear and tear in people who went on
to develop cancer. In fact, they looked like they belonged to a person
who was 15 years older.
Those caps,
known as telomeres, were much shorter than they should be and continued
to get shorter until around four years before the cancer developed,
when they suddenly stopped shrinking. All the people with the changes
went on to develop cancer.
"Understanding this pattern of telomere growth may mean it can be a
predictive biomarker for cancer," said Dr. Lifang Hou, the lead study
author and a professor of preventive medicine at Northwestern University
Feinberg School of Medicine.
"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." Although many people may not want to know that they will develop cancer in the future, it could allow them to make lifestyle changes to lower their risk. Stanford University is also working on a project looking at how telemores can be regrown.
However insurance companies warned that such a test could push up policy premiums.
Matt Sanders, in charge of protection insurance products at GoCompare, said people with such a diagnoses could be priced out of the insurance marker.
“If this test showed 100 per cent probability over a certain number of years then it could affect premiums. It would be the equivalent of living in a high theft area for someone looking for home insurance,” he said.
“Premiums could rise to a point where some people would simply be priced out. However if it was shown that diagnosing earlier could prevent cancer then that could bring down premiums.”
Aviva also said that continually monitored advances in medical sciences ‘ to ensure they are reflected in the premiums paid by our customers, where appropriate.’
Telomeres sit at the end of chromosomes, and protect the tightly bound strands of DNA
In the new study, scientists took multiple measurements of telomeres over a 13-year period in 792 persons, 135 of whom were eventually diagnosed with different types of cancer, including prostate, skin, lung and leukaemia.
Initially, scientists discovered telomeres aged much faster, indicated by a more rapid loss of length, in individuals who were developing but not yet diagnosed with cancer.
Telomeres in all the people who went on to develop cancer looked as much as 15 years older than those of people who were not developing the disease.
But then scientists found the accelerated aging process stopped three to four years before the cancer diagnosis.
Telomeres shorten every time a cell divides. The older a person is, the more times each cell has divided, and the shorter their telomeres.
Because cancer cells divide and grow rapidly, scientists would expect the cell would get so short it would self-destruct. But that's not what happens, scientists discovered.
“We found cancer has hijacked the telomere shortening in order to flourish in the body,” added Dr Hou.
The team is hoping that if it can identify how cancer hijacks the cell, then treatments could be developed to cause cancer cells to self-destruct without harming healthy cells.
The research was published in the online journal Ebiomedicine
