Researchers argue that regularly checking breasts for signs of breast cancer could actually be more harmful to women's health than helpful.
Mammograms decrease a woman's risk of fatal breast cancer by 19 percent (15 percent for women in their 40s and 32 percent for women in their 60s), according to the study, published Tuesday in the Journal of the American Medical Association.
"Teaching women to examine their breasts regularly has been shown not to reduce deaths from breast cancer and actually increases the chances of a benign biopsy result," Dr. McCartney wrote in The Times. "It is unfair to tell women that regular self-examination will save their lives when it may simply incur anxiety and have the potential to harm."
A recent editorial in The Sun entitled "Check 'em Tuesday" encouraging women to regularly self-check for breast cancer lumps prompted McCartney's response.
"If you get a lump you should definitely get it checked," she added. "What I can't say is that checking yourself regularly is a particularly good way of going about saving lives."
About 225,000 cases of breast cancer are diagnosed in the United States each year, and about 40,000 people die of it, according to the American Cancer Society.
Dr. Lydia Pace and Dr. Nancy Keating, who led the recent study, wrote that though annual mammograms reduced the overall death rate from breast cancer by about 19 percent, about 19 percent of breast cancers detected are "over-diagnosed."
They also calculated that only five in 10,000 women in their 50s who undergo annual screenings for 10 years will avoid a breast cancer death. About 6,130 women, on the other hand, will have a false positive result that requires extra X-rays, and 940 will undergo biopsies for nonmalignant findings.
Some experts still believe that the benefit of mammograms and self-checking outweighs the possible risks.
"The overwhelming odds for any one woman to benefit are quite low, but overall, from a population perspective, it's one of our best tools in the war on cancer," Richard Wender, chief cancer control officer at the American Cancer Society, told The Wall Street Journal.