Cleaning Products Linked to Breast Cancer?
Study Suggests Household Cleaning Products May Raise Breast Cancer Risk, but Experts Disagree
Cleaning Products and Breast Cancer: Study Details continued...
For solid air fresheners, for instance, those who used it seven or more times a year had twice the risk of breast cancer as those who never used it.
Brody also found that women who had breast cancer and thought that chemicals and pollutants contribute much to cancer risk were more likely to report high use of cleaning products. But Brody isn't sure what's driving what -- whether women who get breast cancer then begin to wonder if cleaning products played a role, or other factors.
When studies look at data from the past -- what scientists call retrospective studies -- and ask people to rely on their memories, "the results aren't going to be interpretable," says Thun, who reviewed the study findings for WebMD.
''I'd say that the study really isn't informative about their actual risk," he says. "It's much more informative about why this particular line of study is not reliable. It's not informative. And it is not going to answer the questions."
As to the risk of cleaning products, Thun says, "The jury's out. We know there is a lot of concern about cleaning products from environmental groups."
Ideally, the way to study the potential link, he says, is to define the exposure to cleaning products in advance, then follow the women. He concedes this is difficult and time consuming and ''probably not going to happen."
Still, the "self-report" technique is unreliable, he says, especially in those already diagnosed. "If I have breast cancer, I am going to be looking for a reason," he says.
''There's concern because of recall bias," agrees Susan Brown, director of health education at Susan G. Komen for the Cure in Dallas. Understanding the effects of cleaning products will take more study, including research that follows a group of women over time, she tells WebMD.
''It is our experience that once people are diagnosed with breast cancer, they are so interested in trying to figure out what caused it, they look at things in a different way,'' Brown says."They look at every exposure, every behavior as suspect, perhaps part of the reason they got breast cancer. It's perfectly natural, but that doesn't necessarily lead to good science."
What should women concerned about cleaning products do until more research is in? Thun says environmental groups offer suggestions on using simpler cleaning products, such as soap and water and baking soda.
Thun also suggests focusing on known ways to reduce breast cancer risk, including maintaining a healthy weight, engaging in physical activity, minimizing alcohol intake, and avoiding hormone replacement therapy.