Cell Biology and Oncology
Another deadly condition in which sex differences plays a key role is cancer. There are sex discrepancies in the instances, causes and prognoses of various forms of cancer. Men are four times as likely to develop bladder cancer as their female counterparts, but women are 30-50% more likely to die from the disease. Studies have also indicated that women who smoke are at increased risk of Non-Hodgkin’s lymphoma, but have been unable to establish a similar correlation among male smokers.
The leading cause of mortality from cancer is lung cancer in women and prostate cancer in men. Mortality from lung cancer is increasing in women even though death rates from lung cancer are decreasing in men. The steady increase in the disease among women has made it the leading cause of cancer deaths in females since 1987. Part of this difference in lung cancer rates is due to the fact that female smokers are 70% more likely to develop lung cancer than male smokers. Non-smoking females are also more likely than non-smoking males to develop the disease, which leads some scientists to believe that women are more susceptible to environmental factors, including second-hand smoke, than their male counterparts.
Recent studies point to several possible reasons for this. Women are more likely than men to develop cancer after being exposed to low levels of cigarette smoke, possibly because one of the human enzymes that helps metabolize tobacco’s carcinogens protects men more than women. Furthermore, female smokers are more likely to develop two of the most fatal types of lung cancer, small cell lung cancer and adenocarcinoma, while men most frequently develop the comparatively treatable squamous cell variety.