From Terry Martin,
Your Guide to Smoking Cessation.
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Both nonsmoking and actively smoking premenopausal women exposed to secondhand smoke (passive smoking) on a regular basis appear to have an increased risk of getting breast cancer. The results of a review of 19 published studies looking at passive smoking and breast cancer risk were published in the November 2005 issue of International Journal of Cancer.

Dr. Kenneth C. Johnson, of the Public Health Agency of Canada, Ottawa, Ontario studied information from 19 studies that took place between 1966 and 2004 in an effort to understand the association between passive smoking, active smoking and breast cancer risk. The studies were a mixture of cohort studies and case-control studies. Dr. Johnson reviewed these studies in terms of how complete exposure information was. If the study included data about:

• childhood exposure to secondhand smoke from parents
• adult exposure in the home
• adult occupational exposure

it was considered to be a complete study. Of the 19 studies reviewed, only 5 were considered to have complete information about passive smoking, and they were all case-control studies.

General findings based on all 19 studies included:

• Long-term exposure to passive smoking is associated with an overall increased breast cancer risk of 27 percent in life-long nonsmokers
• In premenopausal women fitting the same criteria, the increased breast cancer risk was 68 percent
• Active smoking appeared to raise breast cancer risk by 46 percent

Findings from the 5 studies with complete information on passive smoking included:

• Passive smoking appeared to increase breast cancer risk by 90 percent
• Premenopausal nonsmokers with regular secondhand smoke exposure had an increased risk of 119 percent
• Active smoking raised breast cancer risk by 108 percent

Cigarette smoke contains over 4000 chemical compounds, hundreds of which are either poisonous or carcinogenic. While the link between smoking, either passively or actively and breast cancer is controversial and still being studied, we do know that inhaling the toxins in cigarette smoke is dangerous and potentially deadly to our health.

If you haven't yet quit smoking, don't waste anymore of your precious life on this killer habit. Quit today.

_{Source: Johnson KC. Accumulating Evidence on Passive and Active Smoking and Breast Cancer Risk International Journal of Cancer 2005;117:619-628}