Smoking May Increase Breast Cancer Risk
Study Shows Secondhand Smoke May Also Put Women at Risk
More Research Needed
Not everyone is so certain, however.
Paolo Boffetta, MD, deputy director of the Tisch Cancer Institute at Mount Sinai School of Medicine in New York City, says that while there is growing evidence of a link between smoking and breast cancer, it is still relatively new and needs further study.
“I think it is a bit too early to say,” says Boffetta, who wrote an editorial that accompanies the Luo study. “I’m a little bit cautious, but the evidence is becoming more and more convincing ... it will emerge more strongly in five or 10 years.”
Secondhand Smoke and Breast Cancer Risk
The researchers also looked for a link between breast cancer and secondhand smoke. They found that for women who had the most extensive exposure to secondhand smoke -- in the home or the workplace -- their breast cancer risk was 32% higher than normal.
Margolis is quick to point out that a lot more study is needed to confirm that finding. For one thing, only 12% of the women in the study said that they had not been exposed to secondhand smoke, so the comparison group that the study used was quite small.
“Secondhand smoke was almost ubiquitous,” Margolis says. “Women aged 50-79 are almost universally exposed.”
Though no link has been conclusively established, Margolis does say that it is biologically plausible that heavy secondhand smoke exposure could cause breast cancer.
“The risk is likely to be elevated,” Margolis says. “You see the same type of damage to DNA in their breast cancer tissue in women who smoke and women exposed to secondhand smoke.”
Margolis says that while smoking puts women at greater risk of lung cancer and heart disease, the link to breast cancer might help them pay more attention to the need to quit.
“There are certain women for whom this message will be enough to convince them,” says Margolis. “You can’t change your age, your genes, your family history, but you can add smoking to the list of risk factors.”