Girls who start smoking in their early teens are two-thirds likelier to develop breast cancer later in life compared with non-smokers, a study says.
The research, published in Saturday’s issue of the British medical weekly The Lancet, was based on interviews with more than 1 000 adult women in the western Canadian province of British Columbia who had had breast cancer.
The data was compared with that of more than 1 000 counterparts who had never had the disease.
The risk of breast cancer in adult life was 69% higher for women, who started to smoke within five years of their first menstruation, than for non-smokers.
Lead researcher Pierre Band of the British Columbia Cancer Agency in Vancouver suggests breast tissue is at its most sensitive to tobacco’s carcinogens during puberty, when mammary cells are still developing.
That suspicion was backed by the study’s finding that
post-menopausal women who started smoking after their first pregnancy did not face an increased cancer risk, he said.
Previous studies on women who have had breast cancer from radiation also see an age link with puberty. They have also found, among lab animals, that breast tissue is less susceptible to chemical carcinogens after a first full-term pregnancy.
”Our evidence of the detrimental effect of cigarette smoking on the most frequent sex-specific cancer in women should reinforce the importance of smoking prevention, especially in adolescence,” the authors say. – Sapa-AFP