By New York Times
Smoking causes lung cancer and is implicated in a dozen other cancers, but scientists have generally dismissed its importance in breast cancer, saying it plays little role, if any.
Now, a Canadian panel of experts is challenging the widely held view.
In a report issued Thursday, the panel asserted that evidence from new studies strongly suggests that smoking increases the risk of breast cancer, and warned that girls and young women faced special risks from exposure to smoke. For them, even exposure to secondhand smoke during this critical period of development may increase the risk of breast cancer later in life, the report said.
The report found strong evidence that secondhand smoke contributed to premenopausal breast cancer but did not find enough support to say it increased the risk of postmenopausal breast cancer.
The perspective is a sharp dissent from the consensus among most scientists that there is not enough consistent evidence to determine whether smoking plays a causal role in breast cancer. The International Agency for Research on Cancer said in a recent report that it found little or no link between active smoking and breast cancer, and the surgeon general's office said in 2006 that there was insufficient evidence to say secondhand smoke caused breast cancer.
“One message women have gotten in the past is that ‘you must go for a mammogram, because we can do nothing to prevent breast cancer.' That's absolute nonsense,” said Dr. Anthony Miller, a member of the panel and associate director for research of the University of Toronto's school of public health. “You can be more physically active. You can eat a good diet and avoid becoming overweight. Do not drink heavily – and do not smoke.”
For young women, Miller said, “the message is, Not only will you increase your risk of lung cancer – you know that – what we're telling you is you'll also increase your risk for getting breast cancer. In many respects, that is a more personalized message.”