(Ivanhoe Newswire) -- Even the smallest lung cancers -- the size of a pea -- recur in 30 percent to 40 percent of patients within five years. But now, newly-discovered genetic markers could help determine which of these cancers is likely to attack again.

Researchers at Johns Hopkins Kimmel Cancer Center found genetic markers --chemicals known as methyl groups -- in tumors and tissue removed from patients with early-stage lung cancers. These chemicals aid in cancer development by serving as signals to cells to turn certain genes on or off. Disruption of these signals may result in abnormal proteins that cause cancer.

In the tumor and tissue samples, the team examined seven genes linked to lung cancer development. Four showed the highest amounts of methylation -- p16, H-cadherin, APC and RASSF1A.
 

The study revealed many of the genes in the recurring cancers had twice the amount of methyl markers than in cancers that did not return. Researchers say methylation could increase a patient’s odds of recurrence by five to 25 times.

“The DNA evidence we see for many of the recurring cases suggests it may be wise if our work is confirmed to reclassify such cancers as advanced disease instead of early stage,” Malcolm Brock, M.D., associate professor of surgery at Johns Hopkins University, was quoted as saying.

Researchers say these findings may also lead doctors to consider treating high-risk patients more aggressively with chemotherapy following surgery.


SOURCE: The New England Journal of Medicine, 2008;358:1118-1128