The more you smoke – The more is the risk of breast cancer

Smoking is a controversial lifestyle factor that has been tied to increased breast cancer risk. Studies have yet to decisively prove a link between tobacco smoke and breast cancer, but evidence is piling up.
Most studies have found no link between cigarette smoking and breast cancer. Though the link between smoking and cancers, in general, is indisputable. That smoke contains cancer-causing substances that are absorbed into your body and affect one’s health. The scientists say that tobacco smoke contains numerous potentially harmful substances, including nitrogen oxides, volatile aldehydes, alkenes, and aromatic hydrocarbons, which may act differently and at different stages in the development of breast cancer.
Here are just a few of the 3,000 chemicals in tobacco smoke that are related to cancer:
• Tar – a sticky substance that will be created as tobacco burns. Inhaling while smoking pulls tar into your lungs, where it accrues over time and causes tissue annihilation.
• Nicotine – an exceptionally addictive drug that helps cancers grow. It does not cause cancer, but it can stimulate cancer cell development.
• Nitrosamine – a carcinogenic compound vastly used in cosmetics, processed meats, pesticides, and latex goods.
Studies do show some suggestive links between smoking and breast cancer:
• Second-hand (passive) smoke may increase risk in younger, premenopausal women.
• Teenagers who smoke are more possible to develop breast cancer before menopause.
• Active smoking is linked to aggressive, hormone receptor-negative (HR-) type breast cancer.
• Smoking may promote the spread of breast cancer to your lungs too.
An active focus of research is whether second-hand smoke increases the risk of breast cancer. Both mainstream and second-hand smoke contains chemicals that, in high concentrations, cause breast cancer in rodents. Chemicals in tobacco smoke reaches breast tissue and contaminates even breast milk causing harm to the child.
The evidence on second-hand smoke and breast cancer risk in human studies is controversial, at least in part because smokers have not been shown to be at increased risk. One possible explanation for this is that tobacco smoke may have different effects on breast cancer risk in smokers and in those who are just exposed to smoke.
Modern researches reveal that risk of breast cancer was 60% higher for women who had smoked for 40 years or longer than that of women who had never smoked. Among those who smoked 20 cigarettes or more a day for 40 years, the increased risk rose to 83%. Women who smoke for many years may increase their risk of developing breast cancer. The researchers said that those women who had smoked 20 cigarettes a day or more have proportionate association between smoking and breast cancer risk.

Evidence Relates Smoking to Breast Cancer

In a Swedish study, hormone receptor-negative (HR-) type breast cancer - which is more aggressive and harder to treat, was found to be more common in current and former smokers, The American Cancer Society says.

Researchers at the University of California-Davis Medical Centre found that cigarette smoking was associated with spread of breast cancer to the lungs. Those patients also had higher fatality rates.
Nitrosamine, an ingredient in cigarettes, may be the cause of this effect. A study published in Cancer Research shows that the tobacco-specific nitrosamine NNK may cause genetic mutations in breast tissue in female smokers and females exposed to second-hand smoke. Carcinogenic compounds can be stored in fatty tissue in your breast and have been found in breast fluid of women who smoke.
Findings suggest that smoking of very long duration and high intensity may be associated with increased risk of breast cancer. Albert Einstein College of Medicine researchers, from, Bronx, New York, examined the association between cigarette smoking and incidence of breast cancer in a cohort of women who had smoked for up to 40 years at recruitment in the early 1980s.
The research, using data from almost 90000 women in the Canadian national breast screening study, found that smoking intensity, smoking duration, years since smoking started, and pack years of cigarette consumption had positive associations with breast cancer risk. But age at which smoking began and years since quitting among former smokers were not clearly associated with risk.
The study found that women who had smoked either at least one pack of cigarettes a day for 40 years or at least two packs a day for 20 years were at noticeably higher risk than women who accrued the same number of pack years over a shorter duration.
The risk in association with duration of smoking years since smoking commencement and years since quitting, suggest that smoking may act primarily as an initiator rather than as a promoter of breast cancer, as has been hypothesised with respect to colorectal cancer.
Bottom Line: Stop Smoking, Lower Your Risk
If you smoke tobacco, the substances in tobacco smoke are deposited in your tissues and cause damage, some of which may open the door to damage even your genes too. It will take years to recover a lower level of risk for developing breast cancer if you stop smoke. Still, those are years that may be further to your life.
Tobacco smoke carries carcinogens, which can accumulate in fluid around the breasts. Aggressive smoking can hugely raise the risk of breast cancer. The evidence is piling up for a link between smoking and breast cancer. It's another good reason to stop smoking.
Pregnancy and breastfeeding combined with regular exercise, maintaining a healthy weight, and avoiding alcohol can help lower your risk. Both pregnancy and breast-feeding reduce a woman's total number of lifetime menstrual cycles, and thus helps lower the risk. Having children before age 30 also reduces the risk of breast cancer.