Sweeping new US breast cancer guidelines released recommend
against routine mammograms for women in their 40s, and suggest
women 50 to 74 only get a mammogram every other year.
The new guidelines by the US Preventive Services Task Force, an influential panel of independent experts, would sharply curtail the number of breast mammograms done in the United States, sparing women the worry of false alarms and the cost and trouble of extra tests.
But US cancer experts say the altered schedule may mean more women will die from breast cancer.
The guidelines, published in the Annals of Internal Medicine, are based largely on computer projections from six independent research groups in the United States and Europe.
They predicted that screening women 50 to 69 every other year will catch nearly as many breast cancers - 81% - while producing half as many false positive results.
"Although the USPSTF recognizes that the benefit of screening seems equivalent for women aged 40 to 49 years and 50 to 59 years, the incidence of breast cancer and the consequences differ," the task force, sponsored by the US Agency for Healthcare Research and Quality, wrote.
The group's last recommendations in 2002 called for routine mammograms every one to two years for all women older than 40.
Now, they recommend no routine screening for women in their 40s, and instead suggest these women decide themselves when to start after weighing the risks and benefits.
"This is not a recommendation against mammography for women in their 40s," said Dr Diana Diana Petitti, a professor of biomedical informatics at Arizona State University in Phoenix, who spoke on behalf of the task force.
Petitti said for women in their 60s, the benefits of screening clearly outweigh the harm.
Letting cancer lie
The panel said there is not enough evidence to say women over 74 benefit from mammograms because at that age, screening may be detecting cancers that will not ever kill a woman.
The guidelines also say there is not enough evidence to prove that women benefit from self breast exams, or even if they help if doctors do them.
Dr Daniel Kopans, professor of radiology at Harvard Medical School in Massachusetts, said the new guidelines are scientifically unjustified and will condemn women ages 40 to 49 to unnecessary deaths from breast cancer.
"If you look at their guidelines, they are saying, 'Don't examine yourself, don't let anyone else examine you, and don't get a mammogram.' Where does that leave you? It leaves you waiting to have a big cancer that you can't ignore any more," Kopans said in a telephone interview.
The American Cancer Society will disregard the guidelines.
"The American Cancer Society will continue to recommend that women of average risk of breast cancer start screening at age 40 and get screened every year," Dr Len Lichtenfeld, the group's deputy chief medical officer, said in a telephone interview.
Dr Carol Lee, chair of the American College of Radiology Breast Imaging Commission, said in a statement the recommendations ignore the valid scientific data and place a great many women at risk of dying unnecessarily.
Lee and Lichtenfeld said they fear insurers - both private and public - will use them to pare back health costs.
"These new recommendations seem to reflect a conscious decision to ration care," Lee said, although Petitti said cost was not a factor in their decision-making.
Most countries have settled on a plan for regular mammograms after age 40 or 50 in the hope of detecting tumours while they are small and easily cured.
Breast cancer is the top cancer killer of women globally, killing 500,000 annually.