Women's Risk of Lung Cancer Double That of Men
10-year study shows startling susceptibility
MONDAY, Dec. 1, 2003 (HealthDayNews) -- Being a woman appears to be a major risk factor for lung cancer.
A 10-year study using computed tomography (CT) screening found women had twice the risk of developing lung cancer from using tobacco that men did.
This trial was part of a larger study, the Early Lung Cancer Project (ELCAP) in New York, which found annual CT screening for both men and women could more easily detect early tumors and reduce mortality rates than conventional screening methods.
Both sets of findings were presented Dec. 1 at the annual meeting of the Radiological Society of North America in Chicago.
"The risk ratio of 2-to-1 is very high. It means basically that women are inherently twice as likely to get lung cancer as men," says Dr. Frederic W. Grannis, head of thoracic surgery at City of Hope Medical Center in Duarte, Calif.. "That's not good, particularly since so many young women are now smoking. That means that there is a potential for a worsening epidemic of lung cancer in women in coming years."
Years ago, Grannis adds, women were thought to have a lower susceptibility to lung cancer than men, but that may have been because they were simply not smoking as much. More recently, physicians have suspected women's susceptibility was higher, especially given the fact that women who have never smoked also develop lung cancer, something that rarely happens in men.
According to the American Cancer Society, more people die every year of lung cancer than of breast, colon and prostate cancers combined. The tumors have few early symptoms and are often quite advanced by the time they are detected.
CT scanning uses X-rays to get images of different angles of the body, then uses a computer to show a cross-section of different areas. Not all insurance plans cover the procedure, which typically costs about $300, says lead author Dr. Claudia Henschke, division chief of chest imaging at Weill Medical College of Cornell University in New York City.
The study on gender, which was partially funded by the National Institutes of Health, looked at 2,968 men and women 40 years and older who had some history of tobacco use.
While women who smoked or had smoked had double the risk of developing lung cancer, other risk factors included being over 50, which conferred a 10 times greater risk, and a heavier smoking habit, which increased the risk slightly.
The study did not address why women might be more vulnerable to the disease, although a paper authored by Henschke exploring this fact is about to be published.
The good news is that in both men and women, CT scans managed to catch tumors much earlier than conventional screening methods, according to a trial which looked at 6,318 men and women aged 60 and older who smoked at least one pack of cigarettes a day for 10 years.
This conclusion verified findings from the same trial, which were presented a few years ago. "Over 80 percent of cancers were found at the earliest stage," Henschke says. "That's a dramatic change from 15 percent or less." The earliest stages, she adds, have a much higher cure rate, perhaps up to 50 percent as opposed to 10 percent.
Although some critics have pointed to the problem of detecting growths that eventually prove to be nothing, Henschke says the researchers had measured the tumors and determined "those are cancers that would proceed to kill you."
The message? Quit smoking. And once you've done that, get screened.
"If you're at risk of lung cancer, if you currently smoke or you've been a former smoker and you're at least 50 years or older, you should consider having the scan," Henschke says.
"The evidence is accumulating rapidly that screening for lung cancer is highly effective in picking it up at an early stage," Grannis adds.