Contrary to widespread rumor, there is no evidence to support the idea that use of underarm antiperspirants or deodorants causes breast cancer, according to a study reported in the October 16, 2002 issue of the Journal of the National Cancer Institute (2002;94:1578–1580). This rumor circulated so widely on the Internet it became a public concern, a kind of urban myth, despite the fact there had not been any published, scientific reports suggesting any such association.
In response to the rumor, both the American Cancer Society (ACS) and National Cancer Institute have posted articles on their Web sites to assure the public that there is no scientific basis for this concern. “Even though our antiperspirant article is three years old,” noted Editorial and New Media Director for the ACS, Chuck Westbrook, “it consistently ranks among our most viewed news stories, with more than 10,000 page views in the past year,” he said.
“Most women who contact us about this issue are relieved when we tell them that the claims made in this rumor are inconsistent with what is known about breast cancer risk factors,” says Carol Harrison, a supervisor in the ACS National Cancer Information Center. “But a few have remained concerned because we were unable to refer to a study that specifically addressed this issue. We're relieved that we now have more to reassure these women.”
Dana K. Mirick, MS, and colleagues at the Fred Hutchinson Cancer Research Center in Seattle, conducted a case control study of 813 women aged 20 to 74 living in Washington. These women, diagnosed with breast cancer from 1992 to 1995, were compared with 793 women without the disease. Investigators found no link between breast cancer and regular use of underarm antiperspirants or deodorants even when the products were applied within one hour of underarm shaving. “Specifically, there was concern [expressed in the Internet rumors] that such products might contain harmful substances that could be absorbed via small nicks or abrasions caused by hair removal,” the study authors wrote.
Whether the women used antiperspirants or deodorants, or shaved with a blade razor or used another form of underarm hair removal, there was no evidence of a link to the risk of breast cancer, concluded the authors, who indicated that it was their hope that the findings in their study would “help alleviate the concerns of many that the use of underarm antiperspirants or deodorants could alter their risk for breast cancer.”