Also, the task force said breast self-exams do no good and women shouldn't be taught to do them.
For nearly two decades, the cancer society has been recommending mammograms beginning at 40. But the government panel of doctors and scientists concluded that getting screened so early and so often is harmful, causing too many false alarms and unneeded biopsies without substantially improving women's odds of surviving the disease.
"The benefits are less and the harms are greater when screening starts in the 40s," said Dr. Diana Petitti, the vice chairwoman of the panel.
The new guidelines were issued by the U.S. Preventive Services Task Force, whose stance influences coverage of screening tests by Medicare and many insurance companies. But Susan Pisano, a spokeswoman for America's Health Insurance Plans, an industry group, said insurance coverage isn't likely to change because of the new guidelines.
"Our concern is that as a result of that confusion, women may elect not to get screened at all. And that, to me, would be a serious problem," said Dr. Len Lichtenfeld, the cancer society's deputy chief medical officer.
The guidelines are for women who are not at high risk of breast cancer .
The new advice says:
- Most women in their 40s should not routinely get mammograms.
- Women 50 to 74 should get a mammogram every other year until they turn 75, after which the benefits are unknown.
- The value of breast exams by doctors is unknown , and breast self-exams are of no value.
The guidelines and research supporting them were released Monday and are being published in to day's issue of the Annals of Internal Medicine.
The new advice was sharply challenged by 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 concluded screening 1,300 women in their 50s to save one life is worth it, but screening 1,900 women in their 40s to save a life is not, Dr. Brawley wrote.