Bras and Cancer
You may have heard this rumor that has been circulating on the internet for years. It is right up there with deodorants cause breast cancer and all the "facts" attributed to Johns Hopkins that have no validity at all (either the facts or the connection with Hopkins). This is from The New York Times Science section this week and is a neat rebuttal of the bras cause cancer rumor. As a reminder, no one knows what causes breast cancer except in the case of those women who carry a gene mutation (BRCA1 or BRCA2). The rest of us are just unlucky.
Bras and Cancer
By C. CLAIBORNE RAY
Q. Is there any truth to the Internet rumor that the incidence of breast cancer is more than 100 times greater in women who always wear bras than in women who never wear bras?
A. "The short answer is no," Dr. Ted Gansler, director of medical content for the American Cancer Society, replied in an e-mail message.
There is no scientifically credible evidence of this, he said, and the proposed mechanism — that bras prevent elimination of toxins by blocking lymph flow — is not in line with scientific concepts of how breast cancer develops.
Internet traffic on the issue is mostly inspired by one study with several scientific flaws, Dr. Gansler said.
The study, never published in a peer-reviewed journal, did not adjust for known breast cancer risk factors that might be associated with bra-wearing behavior, like weight and age. Also, study participants knew the hypothesis before taking the survey.
"Because the idea of bras' causing breast cancer is so scientifically implausible, it seems unlikely that researchers will ever spend their time and resources to test it in a real epidemiological study," Dr. Gansler said.
He and colleagues compared National Cancer Institute data on breast cancer risk for women treated for melanoma who had several underarm lymph nodes removed and those who did not. The surgery, which is known to block lymph drainage from breast tissue, did not detectably increase breast cancer rates, the study found, meaning that it is extremely unlikely that wearing a bra, which affects lymph flow minimally if at all,
would do so.