It had seemed to me on an anecdotal basis that cases of lung cancer in non-smoking patients were more common in women. It now turns out that this may be true with estrogen suggested as the culprit (see: Lung Cancer in Women on the Rise; subscription required), Below is an excerpt from the article:
As doctors have substantially brought down the rate of lung cancer in men over the past three decades, they face a stubborn riddle: Why does it continue to grow among women? A new study offers an intriguing possibility that the answer may involve estrogen. Lung cancer is the leading cancer killer of both women and men. And overall, it still kills more men than women: Some 71,000 deaths are projected in women and 86,000 in men in 2010. That's a much higher casualty rate than the No. 2 killer, breast cancer, with about 40,000 deaths expected, according to the American Cancer Society. Experts don't agree on whether women are naturally at greater risk for lung cancer or more vulnerable to the effects of tobacco smoke than men. Still, there are striking gender differences in cancer rates. For instance, women who have never smoked are far more likely than men who have never smoked to get lung cancer, according to data from the National Cancer Institute. The diagnostic trajectory among women is concerning. Researchers are trying to understand why it is rising and what can be done to change it....The rate of new cases of lung cancer has dropped for men to 72 in 100,000 males in 2007 from 89.5 in 100,000 in 1975. In women, however, the number of cases has more than doubled to 53 in 100,000 females in 2007 from 24.5 per 100,000 in 1975, according to the National Cancer Institute. The hormone estrogen is a possible culprit. Certain forms of estrogen are known to help create genetic mutations in cells and contribute to tumor formation in the breast. Recently, researchers found out that lung cells in both women and men also make estrogen, raising the possibility that the hormone contributes to lung-cancer development.
The graph for lung cancer new case rates by sex presented in the WSJ article was striking and I present it below. If this trend continues, lung cancer will be become mainly a disease of women shortly.
How many people on the street would know that lung cancer kills more women than breast cancer? Please don't confuse the casualty rate for lung cancer with the incidence (i.e., number of new cases) of malignant breast lesions. All women will know of friends or relatives with breast cancer but almost certainly a lesser number with lung cancer. Many breast lesions are discovered in their early stages and there is effective therapy available across most stages of the disease for most histologic types. The WrongDiagnosis web site quotes the following statistics: 22.3% of Americans smoke (CDC); 23 million American women smoke (NHLBI). Ladies, no one wants to tamper with your estrogen levels but do you really need to smoke?