"Long before it's in the papers"
February 17, 2016

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New cancer predictor: aging too fast, scientists claim

Feb. 17, 2016
Courtesy of Northwestern University
and World Science staff

If you age too fast, your risk of get­ting can­cer goes up, ac­cord­ing to a new study that al­so may point the way to med­i­cal tests and lifestyle im­prove­ments to help mit­i­gate the prob­lem.

Peo­ple fac­ing this ac­cel­er­ated ag­ing, ac­cord­ing to the scient­ists be­hind the stu­dy, have a “bi­o­log­i­cal age” high­er than their “chrono­log­i­cal age.” The dis­crep­an­cy “ap­pears to be a prom­is­ing tool that could be used to de­vel­op an early de­tec­tion blood test for can­cer,” said Li­fang Hou of North­west­ern Un­ivers­ity in Chi­ca­go, who led the stu­dy. 

Hou and col­leagues al­so use the term “epi­ge­netic age” in­stead of bi­o­log­i­cal age. This is based on a the­o­ry that bi­o­log­i­cal age in large part re­flects “epi­ge­netic” changes—al­tera­t­ions that can af­fect your ge­nome with­out chang­ing its DNA code.

“Peo­ple who are healthy have a very small dif­fer­ence be­tween their ep­i­ge­net­ic/bi­o­log­i­cal age and chron­o­log­i­cal age,” Hou said. “Peo­ple who de­vel­op can­cer have a large dif­fer­ence and peo­ple who die from can­cer have a dif­fer­ence even larg­er than that. Our ev­i­dence showed a clear trend.”

Re­search­ers cal­cu­lat­ed ep­i­ge­net­ic age, he ex­plained, us­ing a for­mu­la that takes in­to ac­count 71 blood mark­ers. These are mod­i­fi­a­ble by fac­tors in­clud­ing en­vi­ron­men­tal chem­i­cals, obes­ity, ex­er­cise and di­et.

The test is­n't com­mer­cially avail­a­ble but is cur­rently un­der study by re­search­ers, in­clud­ing at North­west­ern, he added. The blood mark­ers re­flect DNA me­thyla­t­ion, an im­por­tant type of ep­i­ge­net­ic change in which a clus­ter of mo­le­cules latches on to a gene and changes its re­cep­ti­vity to bio­chem­i­cal sig­nals from the body.

The pa­per was pub­lished Feb. 15 in the jour­nal EBioMedicine.

The study was based on mul­ti­ple blood sam­ples col­lect­ed from 1999 to 2013. Sci­en­tists used 834 blood sam­ples col­lect­ed from 442 par­ti­ci­pants deemed can­cer-free at the time of the blood draw.

For each year in­crease in the ep­i­ge­net­ic-chron­o­log­i­cal dis­crep­an­cy, the study found a 6 per­cent in­creased risk of get­ting can­cer with­in three years and a 17 per­cent in­creased risk of can­cer death with­in five years. Those who will de­vel­op can­cer have an ep­i­ge­net­ic age about six months old­er than their chron­o­log­i­cal age; those who will die of can­cer are about 2.2 years old­er, the study al­so found.

“Our re­sults sug­gest fu­ture re­search­ers should fo­cus on the ep­i­ge­net­ic-chron­o­log­i­cal age dis­crep­an­cy for its po­ten­tial to show a big pic­ture snap­shot of hu­man health and dis­ease at a mo­lec­u­lar lev­el,” said Yi­nan Zheng, one of the re­search­ers, al­so at North­west­ern. The sci­en­tists now are stu­dying wheth­er peo­ple can low­er their ep­i­ge­net­ic age through lifestyle im­prove­ments such as in­creas­ing ex­er­cise and hav­ing a health­i­er di­et, not­ed Bri­an Joyce, al­so a co-author at the school.


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When you age too fast, your risk of getting cancer goes up, according to a new study that also may point the way to medical tests and lifestyle improvements to help mitigate the problem. People facing this accelerated aging, according to the epidemiologists behind the study, have a “biological age“ higher than their “chronological age.“ And the discrepancy “appears to be a promising tool that could be used to develop an early detection blood test for cancer,“ said Lifang Hou from Northwestern University in Chicago, who led the study. Hou and colleagues also use the term “epigenetic age“ instead of biological age. This is based on a theory that biological age in large part reflects “epigenetic“ changes—alterations that can affect your genome without changing its DNA sequence. “People who are healthy have a very small difference between their epigenetic/biological age and chronological age,“ Hou said. “People who develop cancer have a large difference and people who die from cancer have a difference even larger than that. Our evidence showed a clear trend.“ Researchers calculated epigenetic age, he explained, using a formula that takes into account 71 blood markers. These are modifiable by factors including environmental chemicals, obesity, exercise and diet. The test isn't commercially available but is currently under study by researchers, including at Northwestern, he added. The blood markers reflect DNA methylation, an important type of epigenetic change in which a cluster of molecules latches on to a gene and changes its receptivity to biochemical signals from the body. The paper was published Feb. 15 in the journal EBioMedicine. The study was based on multiple blood samples collected from 1999 to 2013. Scientists used 834 blood samples collected from 442 participants who were free of cancer at the time of the blood draw. For each one-year increase in the discrepancy between chronological and epigenetic ages, there was a 6 percent increased risk of getting cancer within three years and a 17 percent increased risk of cancer death within five years, the study found. Those who will develop cancer have an epigenetic age about six months older than their chronological age; those who will die of cancer are about 2.2 years older, the study also found. “Our results suggest future researchers should focus on the epigenetic-chronological age discrepancy for its potential to show a big picture snapshot of human health and disease at a molecular level,“ said Yinan Zheng, one of the researchers, also at Northwestern. The scientists now are studying whether people can lower their epigenetic age through lifestyle improvements such as increasing exercise and having a healthier diet, noted Brian Joyce, also a co-author at the school.