breast cancer and passive smoking

Smoking is associated with an increase in breast cancer risk among postmenopausal women but there seems to be a definite increase also in non smoker women who have been extensively exposed  to second hand smoke.  These data were recently reported in the British Medical Journal. The study was based on the observation of nearly 80,000 women aged between 50 and 79 years  enrolled in the Women’s Health Initiative Observational Study from 1993 to 1998. Invasive breast cancer appeared in 3,250 women during 10 years of follow-up. Smokers had a 16% increased risk of developing breast cancer after the menopause as compared to non smokers.  For ex-smokers the risk was 9% and continued for up to 20 years after an individual had stopped smoking. The highest breast cancer risk was found among women who had smoked for over 50 years or more. What about non smokers? women who had never smoked but had lived or worked with smokers for prolonged times also appeared to be at increased risk for breast cancer. In particular, over 10 years’ exposure in childhood, over 20 years’ exposure as an adult at home and over 10 years’ exposure as an adult at work, increased the risk by 32% compared with those who had never been exposed to passive smoking. In low income and developing countries large declines in mortality are projected to occur in the near future for all of the principal communicable disease, maternal, peri-natal and nutritional causes, with the exception of HIV/AIDS. Meanwhile, the aging of the global population will result in significant increases in the total number of deaths caused by most non-communicable diseases  such as cancer. In particular, increases in the prevalence of tobacco consumption and significant lifestyle changes in the population are bound to produce an increased risk of breast cancer in African women.  Thus, efficient screening procedures for early detection of the disease need urgently to be implemented.