LOS ANGELES, Nov. 1 (Xinhua) -- U.S. researchers have
found a mechanism to predict survival in women aged 65 and older with early
stage lung cancer.
The new study, published on Thursday in the medical
journal Cancer Research, links high levels of aromatase, an enzyme that makes
estrogen from another hormone called androgen, to a more aggressive and lethal
form of the cancer.
The study was conducted by researchers at the Jonsson
Comprehensive Cancer Center of the University of California in Los Angeles
(UCLA).
The discovery is important because it can help
predict survival at an early stage of the disease, when there are still more
treatment options available. It can also help doctors determine the need for a
more aggressive therapy in patients with high levels of the enzyme.
"All indications suggest that this is a very powerful
prognostic marker that lets us predict which patients have a higher likelihood
of prolonged survival versus death from lung cancer," said Lee Goodlick, a
researcher at the Jonsson Center and senior author of the study.
The findings also suggest that aromatase inhibitors,
which are already being used for the treatment of breast cancer, could also be
used to treat lung cancer.
Based on research performed at the center, scientists
already knew that estrogen plays a role in lung cancer, just as it does in
breast and ovarian cancers. What they did not know was that high aromatase
levels play such an important role in the growth of lung cancer in older women.
Scientists do not know yet why those levels do not have the same effect on
younger women and on men.
"We need to figure out all the strategies that a lung
cancer cell uses to trigger and amplify the estrogen pathway," Goodlick said.
"In women over 65, one trick the cancer cells appear to use is increasing
aromatase. It remains an interesting mystery what strategy the cancer cells are
using in women under 65 and in men."
"Identifying which branch of the estrogen pathway is
hijacked by cancer cells will allow us to specifically attack that branch on a
person-by-person basis. I think this study is one important step in that
direction."
The number of women with lung cancer has been increasing for decades and the disease is the leading cancer killer in women.
