Most women don't need a mammogram in their 40s and should get one every two years starting at 50, a government task force said Monday. It's a major reversal that conflicts with the American Cancer Society's long-standing position.
Also, the task force said that breast self-exams do no good and that women shouldn't be taught to do them.
For most of the past two decades, the cancer society has been recommending annual mammograms beginning at 40.
But the government panel of doctors and scientists concluded that getting screened for breast cancer so early and so often leads to too many false alarms and unneeded biopsies without substantially improving women's odds of survival.
"The benefits are less and the harms are greater when screening starts in the 40s," said Dr. Diana Petitti, vice chair of the panel.
The new guidelines were issued by the influential U.S. Preventive Services Task Force and already are igniting a heated debate among experts. Both the cancer society and the American College of Obstetricians and Gynecologists are standing by their advice that women in their 40s continue to get regular mammograms. And experts did not expect a change in insurance or Medicare coverage because of the new guidelines.
The new recommendation "absolutely" is adding some confusion to a procedure that few women look forward to anyway, said Dr. Catherine Lynch, interim chair of the department of obstetrics and gynecology at the University of South Florida, who plans to counsel patients to stick with the recommendations of the ob/gyn college. She noted that women are very afraid of not knowing about a cancer that might be there.
"I think they've got to look at their own individual risk and realize that we try to do as best as we can on the screening tests, but mammography is not a perfect screening test," she added. "Until we find the ideal test, we can only deal with what we have."
The screening guidelines issued by the Department of Health and Human Services task force recommend against routine screening mammography in women 40-49. They would scale back screening for women 50-74, to every other year from annually.
The guidelines are for the general population, not those at high risk of breast cancer because of family history or gene mutations that would justify having mammograms sooner or more often.
They were released Monday and are being published in today's issue of the Annals of Internal Medicine.
Already, they have drawn sharp challenges from the cancer society.
"This is one screening test I recommend unequivocally and would recommend to any woman 40 and over," the society's chief medical officer, Dr. Otis Brawley, said in a statement.
The task force advice is based on its conclusion that screening 1,300 women in their 50s to save one life is worth it, but that screening 1,900 women in their 40s to save a life is not, Brawley wrote.
That stance "is essentially telling women that mammography at age 40 to 49 saves lives, just not enough of them," he said. The cancer society feels the benefits outweigh the harms for women in both groups.
International guidelines also call for screening to start at age 50; the World Health Organization recommends the test every two years. Britain says every three years.
Breast cancer is the most common cancer and the second leading cause of cancer deaths in American women. More than 192,000 new cases and 40,000 deaths from the disease are expected in the U.S. this year.
Mammograms can find cancer early, and two-thirds of women over 40 report having had the test in the previous two years. But how much they cut the risk of dying of the disease, and at what cost in terms of unneeded biopsies, expense and worry, have been debated.
Mammogram costs may vary by region and rates that insurance companies negotiate with providers. Medicare pays $89 for a standard mammogram, according to a spokesman for the American College of Radiology, which criticized the new guidelines.
Still, in most women, tumors are slow-growing, and that likelihood increases with age. So there is little risk by extending the time between mammograms, some researchers say. Even for the minority of women with aggressive, fast-growing tumors, annual screenings aren't enough to make a significant difference in survival odds.
The new guidelines balance these risks and benefits, scientists say. The probability of dying from breast cancer after age 40 is 3 percent, they calculate. Getting a mammogram every other year from ages 50 to 69 lowers that risk by about 16 percent.
"It's an average of five lives saved per thousand women screened," said Dr. Jeanne Mandelblatt, a Georgetown University researcher.
Starting at age 40 would prevent one additional death but also lead to 470 false alarms for every 1,000 women screened. Continuing mammograms through age 79 prevents three additional deaths but raises the number of women treated for breast cancers that would not threaten their lives.
"You save more lives because breast cancer is more common, but you diagnose tumors in women who were destined to die of something else. The overdiagnosis increases in older women," Mandelblatt said.
She led six teams around the world who used federal data on cancer and mammography to develop mathematical models of what would happen if women were screened at different ages and time intervals. Their conclusions helped shape the new guidelines.
Several medical groups say they are sticking to their guidelines that call for routine screening starting at 40.
"Screening isn't perfect. But it's the best thing we have. And it works," said Dr. Carol Lee, a spokeswoman for the American College of Radiology. She suggested that cutting health care costs may have played a role in the decision, but Petitti said the task force does not consider cost or insurance in its review.
Dr. Amy Abernethy of the Duke Comprehensive Cancer Center agreed with the task force's changes. Abernethy, who is 41, said she got her first mammogram the day after her 40th birthday, even though she wasn't convinced it was needed. Now she doesn't plan to have another mammogram until she is 50.
Barbara Brenner, executive director of the San Francisco-based Breast Cancer Action, said the group was "thrilled" with the revisions. The advocacy group doesn't support screening before menopause and will be changing its suggested interval from yearly to every two years, she said.
Information from the Associated Press, New York Times and Times Staff Writer Letitia Stein and Times researcher John Martin was used in this report.