A new study, prompted by an urban myth that Internet users embraced and spread, shows there is no evidence that antiperspirants or deodorants can cause breast cancer.
The study, appearing this week in the Journal of the National Cancer Institute, examined the personal hygiene habits of 813 women with breast cancer and 793 women without the disease and found no link between cancer and body odor control cosmetics.
"Antiperspirant and deodorant use did not differ whether or not a participant (in the study) had breast cancer," said Dana K. Mirick, an epidemiologist at the Fred Hutchinson Cancer Research Center in Seattle. This indicates, she said, that use of the personal products does not cause the disease.
Mirick, first author of the study, said that the data was collected starting in 1992 as part of a larger study testing if other common exposures might be factors in breast cancer.
"About that time, these rumors (about antiperspirants and cancer) started to pop up on the Internet," said Mirick. "So we threw in these additional questions."
Other results from the large study were published earlier, but nothing was done about the antiperspirant question until Mirick and her co-authors realized that women were still concerned about the issue, even 10 years after it was first raised on the Internet. The American Cancer Society and the National Cancer Institute were so concerned that both put out notices on the Internet stating there was no evidence linking the personal products with cancer.
"On the main Fred Hutchinson line they still occasionally get phone calls from women who are concerned about this," said Mirick. "Even though no researchers believed there was a connection, there were no published studies on it."
Since they had the data, she and her co-authors decided to write up a paper and, perhaps, lay to rest a persistent myth.
"It is important for people to have correct information ... that can eliminate fear about a deadly disease from an exposure that is quite common," said Mirick. "These myths induced fear because this is a product that almost everybody uses."
Mirick said the original rumor started more than 10 years ago, probably from a widely distributed, anonymous e-mail.
She looked for a Web site that carried the myth, but found nothing.
"I don't know if there was ever a Web site, or if it just came from a round robin E-mail," said Mirick. "But I do know the question was raised before 1992. ... People were concerned."