Breast Cancer and Secondary Smoke
According to one of the largest studies to date on passive smoking and breast cancer in women conducted by the Northern California Cancer Center, women who never smoked cigarettes and who were exposed to secondhand cigarette smoke over a lifetime—especially during adulthood—had a significantly increased breast cancer risk later in life.
This study covered more than 57,000 women in the ongoing California Teachers Study to examine their lifestyle, medical history and women's health since it began in 1995. In the 12 years since the initial questionnaires were completed, 1,754 newly diagnosed cases of invasive breast cancer occurred in teachers participating in the study.
Breast cancer risk increased with higher levels of exposure, and postmenopausal women with exposures at or after age 20 had the greatest risk increase at 25%.
In Hong Kong, the smoking prevalence of daily cigarette smokers aged 15 or above was 11.8% (676,000+) in 2008 whereas the smoking prevalence of women smokers was 3.6%.
Cigarette is one of the major risk factors for cancers and cardiac diseases. Breast cancer is the most common cancer affecting women in the world. A global estimation of 1.15 million new cases was reported in 2002. Breast cancer is the most common cancers in Hong Kong women. The number of breast cancer cases diagnosed for females doubled from 1,152 in 1993 to 2,701 in 2007, representing an average annual increment of 6.4%. Breast cancer was the third major causes of cancer death in Hong Kong women in 2007.
1. The Northern California Cancer Center (http://www.nccc.org)
2. The American Association for Cancer Research (http://www.aacr.org)
3. Hong Kong Cancer Registry, Hospital Authority (http://www3.ha.org.hk/cancereg/e_stat.asp)
4. Hong Kong Breast Cancer Foundation (http://www.hkbcf.org)