(AP) -- Are doctors overtreating breast cancer? At a breast cancer conference Friday in Barcelona, experts discussed how to implement mammogram screening programs across Europe, balancing fighting cancer with the goal of targeting only those women who need to be screened.
For years, officials have promoted breast cancer screening as the best way to spot the disease and save lives. Yet mammograms are far from perfect and come with an unwelcome side effect: false alarms and unneeded biopsies, without substantially improving women's odds of survival.
The mammogram issue ignited a fierce debate in the United States last year when an influential government panel recommended scaling back screening programs to begin at age 50 instead of 40 - guidelines close to many in Europe.
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, tumors, annual screening seems to make little difference in survival odds.
U.S. researchers last year estimated five lives saved per thousand women screened.
"The over-diagnosis problem has been downplayed because people really want to believe screening works," said Karsten Jorgensen of the Nordic Cochrane Centre in Copenhagen, who has published several papers on the issue. "There is a lot of overtreatment happening, and it is time to re-evaluate whether the benefits really outweigh the harms."
Yet others say doctors must work with the tests they have.
"Maybe in 20 years we will have a better test to tell us which cancers are the dangerous ones," said Ingrid Kossler, president of the Swedish Breast Cancer Association, who chaired the session Friday on screening guidelines. "But until then, we have to use what we have and treat the cancers we find."
Previous studies have shown breast cancer screening programs in countries including Britain, Canada, Denmark and Sweden can lead to unnecessary treatment. In those countries, and in much of Europe, women aged 50 to 70 get a mammogram every two years.
Until last year, U.S. recommendations were for women at average risk to begin getting mammograms at age 40. But new guidance suggested starting at 50 instead and having a mammogram only every two years - advice that was rejected by the American Cancer Society and some other experts.
Jorgensen said screening has become more of a political issue than a medical one. Officials have spent so many years convincing women to get mammograms that it will be difficult to now change policies, especially with a very vocal and powerful breast cancer lobby.
"It would take a very courageous politician to go up against mammograms," Jorgensen said.
But reducing the number of women who are being unnecessarily treated also increases the risk that women with breast cancer will be missed.
"We need more targeted screening to identify women who can really benefit from it," said Jack Cuzick, head of epidemiology at the Wolfson Institute of Preventive Medicine in London.
Astrid Scharpantgen, who spoke at Friday's session on European screening guidelines, said many countries are still rolling out mammogram programs. She studies mammogram screening across Europe at Luxembourg's ministry of health.
Many countries are still trying to persuade women to be screened, and the problem of overtreatment won't help. In 2007, 59 million women across Europe were eligible to get a mammogram in national screening programs. Yet only about 12 million turned up.
(This version corrects to remove erroneous statement that colon cancer screening in doubt.)