The Myth of Bras and Breast Cancer

If you’ve spent time on the Internet, chances are you’ve seen chatter about the association between wearing a bra and breast cancer.

As C. Claiborne Ray explains in Monday’s Science Times, the claim has no basis in fact and stems from a flawed study that was never published in a peer-reviewed medical journal.

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.

SOURCE: nytimes