DALLAS - April 21, 1999 - Once again evidence says that differences exist between the sexes. Researchers have discovered that men and women may not in fact be equal - at least with respect to the pattern of precancerous lesions in the lungs of current and former smokers.
Dr. Adi Gazdar, UT Southwestern professor of pathology, Dr. Stephen Lam and colleagues in Canada and other investigators at the National Cancer Institute in Bethesda, Md., have published the first study that analyzes the gender differences in precancerous changes in smokers' lung tissue. This study, in the April 21 issue of the Journal of the National Cancer Institute, finds that women develop a different pattern of bronchial changes than men do; that airflow obstruction, a common means to assess those at risk of lung cancer, does not seem to be valid especially for women; and that lung damage due to smoking persists for many years and probably for life.
More men and women die from lung cancer than from any other type of cancer. This year an estimated 171,600 new cases of lung cancer will be diagnosed, and 158,000 people will die from this disease. Approximately 50 percent of lung cancer occurs in former smokers. Women are more susceptible to the harmful effects of tobacco-related carcinogens - the odds ratios for major types of lung cancer are consistently higher in women than in men at every level of exposure to cigarette smoke. Furthermore, this gender difference cannot be explained by differences in baseline exposure, smoking history or body size; it is likely due to women's higher susceptibility to tobacco carcinogens.
"Cancer is the result of a complex multistep process," said Gazdar, associate director of the Nancy B. and Jake L. Hamon Center for Therapeutic Oncology Research. "We are actively trying to develop methods of early detection and chemoprevention - ways to chemically reverse precancerous lesions and block cancer development - for those at high risk."