It's a red-light warning to women and girls: Don't take up smoking, or you should kick the habit if you're a smoker.
"Our hope is that this puts this on women's radar. Ask women what they worry about most, it's breast cancer. They should be worrying about lung cancer," researcher Jyoti Patel, MD, an oncology researcher at Feinberg School of Medicine at Northwestern University in Chicago, tells WebMD.
Her report appears in the new issue of TheJournal of the American Medical Association.
"We need to protect our daughters and granddaughters from being suckered by the tobacco industry," Michael Thun, MD, head of epidemiological research for the American Cancer Society, tells WebMD. "There is a global effort from tobacco companies to capitalize on the women's movement and the growing sense of independence and pride, to entrap women and girls into smoking."
Women, Biology, and Lung Cancer
Patel's report outlines research thus far on women's lung cancer risk, including the surgeon general's 2001 "Women and Smoking" report, which noted that the 600% increase in the death rate from lung cancer in women was a "full-blown epidemic."
Among the findings Patel cites:
- Lung cancer appears to be a different disease in women, with women getting certain forms of lung cancer more often than men. Women get many more cases of adenocarcinoma lung cancer, whereas men develop squamous cell cancer.
- Infection with certain strains of the human papillomavirus (HPV) seems to increase women's risk of lung cancer -- but not men's risk.
- Women smokers have more DNA damage than men, likely because women's DNA repair capability seems to be less effective than men's.
- Estrogen, which has been found in lung tumors, may play a role in lung cancer. One study showed that estrogen therapy after menopause was associated with adenocarcinoma lung cancer.
- Women have about 1.5-fold higher risk of developing lung cancer than men do, according to a large American Health Foundation study of nearly 4,000 men and women.
- However, two studies from the American Cancer Society, found just the opposite -- that men were at greater risk than women. But women may have kept their cigarette smoking habits secret from surveyors. Also, those researchers did not take passive smoking into account, writes Patel.
"I think the evidence is still really controversial whether women are actually at higher risk than men of developing lung cancer -- I think that's still an open question," Patel tells WebMD.
However, women seem to be more vulnerable to the cancer-causing effects of tobacco. "Women have a significantly different biology in the development of their cancers," she explains. "That means there are biological pathways that we don't understand yet. The message is that women's lung cancer is different. That area is ripe for more study."
Because many enzymes that detoxify cancer-causing substances are hormone-triggered, estrogen could impede this process. "Studies have shown that women don't have as much DNA repair capability -- and so far, that's only been seen in lung cancer. There have been some good studies showing that DNA repair capacity is generally worse in women than men."
"Sure, there are huge biological differences between men and women, but I don't feel those biological differences are the central issues with respect to smoking," Thun tells WebMD. "More central to smoking are immunizing young girls and women against the fraud marketing techniques of the tobacco industry."
"The increase in women's lung cancer is because cigarette smoking among women increased -- that's the real message," says Thun.