Once thought of as a disease that mainly affected men, lung cancer rates in women have been rising over the last century as more and more women have become smokers. In fact, lung cancer is now the leading cause of cancer death in American women. Although lung cancer incidence is greater in men than in women because of differences in patterns of smoking habits, several studies in the 1990s suggested that women may actually be more susceptible to lung cancer than men, so researchers started to search for biological rationales for this susceptibility. Other studies, however, have not found any difference in lung cancer risk.
To clear up the controversy, Diane Feskanich, Sc.D., of Brigham and Women's Hospital in Boston, and colleagues analyzed prospective information on 60,296 women from the Nurses' Health Study and 25,397 men from the Health Professionals Follow-up Study. After controlling for age, number of cigarettes smoked each day, age a person began smoking, and time since quitting, the researchers found no difference between men and women in overall lung cancer susceptibility.
The researchers also reviewed six published prospective cohort studies that had examined the issue. When smoking rates were equal, none of the studies showed that women had a higher risk of lung cancer than men. However, the authors note that these analyses and reviews of other studies leave open the possibility that the risk of some particular subtype of lung cancer may be higher in women than in men, though overall risk is not different.
"[I]n the context of what is now a substantial body of prospective evidence, it becomes very difficult indeed to argue the case for inequality of smoking-related lung cancer susceptibility," the authors write. "…The continuing convergence of smoking patterns and lung cancer rates among men and women points to the primary need to focus broadly on enhancing preventive interventions that will have similar relevance for all."
In an editorial, William J. Blot, Ph.D., and Joseph K. McLaughlin, Ph.D., of the International Epidemiology Institute in Rockville, Md., and Vanderbilt University Medical Center in Nashville, Tenn., review past research that has attempted to confirm or explain the perceived difference in lung cancer rates in male and female smokers. They note the consistency of the cohort data in failing to find higher smoking-related risks among women, and that smoking curtailment is the key to prevention among men and women. However, they also write that "the possibility remains that some differences in the way females and males are exposed to and/or respond to carcinogenic agents do exist and that exploration of these differences may be of benefit in reducing the toll of lung cancer among both sexes."
Contacts:
- Article: Amy Dayton, Brigham and Women's Hospital, 617-534-1603, adayton2@partners.org
- Editorial: Maida Montes, International Epidemiology Institute, 301-517-4163, maida@iei.ws
Citations:
- Article: Bain C, Feskanich D, Speizer FE, Thun M, Hertzmark E, Rosner BA, et al. Lung Cancer Rates in Men and Women With Comparable Histories of Smoking. J Natl Cancer Inst 2004;96:826-34.
- Editorial: Blot WJ, McLaughlin JK. Are Women More Susceptible to Lung Cancer? J Natl Cancer Inst 2004;96:812-3.
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