"Getting screening mammograms every two years instead of annually reduces the chance of a false alarm a new study shows. The frequency of screening mammograms  and the appropriate age to begin them  has been debated since the U.S. Preventive Services https Task Force in  recommended that women routinely get screening mammograms every other year starting at age . The task force says the decision to start regular biennial mammograms before age  should be an individual choice based on each patients situation. Meanwhile the American Cancer https Society continues to recommend that women get mammograms every year beginning at age . Researchers analyzed data from nearly  women who had their first screening mammogram https at age  to  years and almost  women with invasive breast cancer https Information about the women and their mammograms came from the Breast Cancer https Surveillance Consortium funded by the National Cancer https Institute. FalsePositives Are Common After  years of annual screening more than half of women will be called back at least once for another mammogram https And  to  will be told they should have a biopsy because of something suspicious that turns out not to be cancer https the researchers concluded. Those falsepositives may cause inconvenience and anxiety https and biopsies https can cause pain https and scarring the researchers note. They found a small but not significant increase in the chance that women diagnosed with breast cancer https had a more advanced case if they underwent screening every other year instead of every year. The study wasnt really designed to answer the question of which screening regimen is best study researcher Rebecca Hubbard PhD says. Its main message Hubbard says is that callbacks or recalls for falsepositive results are common so women shouldnt panic when they occur. In most cases a recall doesnt mean you have cancer says Hubbard a biostatistician at the Group Health Research Institute in Seattle. Hopefully there will be less anxiety https about getting a recall. Women can halve their risk of a callback for a falsepositive if the interpreting radiologist has previous mammograms for comparison the researchers found. Ideally Hubbard says primary care doctors should talk to women about what to expect from annual and biennial screening before they get their first mammogram. Digital vs. Film Mammography In a related study researchers found that digital and film mammography were similarly effective in picking up cancers in most women. Digital and film mammography both use Xray. But in film mammography the image is created directly on a film while digital mammography takes an electronic image that is stored in a computer. Unlike with film mammography radiologists can use software to manipulate digital mammograms https so they may be easier to interpret. The FDA approved the first digital mammography system nearly  years ago before any large studies had compared it to film mammography says Karla Kerlikowske MD author of the second paper. By the time the first such study began enrolling women a decade ago the horse had left the barn says Kerlikowske a professor of medicine at the University of California San Francisco. Today she says more than twothirds of accredited mammography machines in the U.S. are digital which is more expensive than film. Kerlikowske and coresearchers analyzed realworld data from about  women aged  to  who underwent nearly  mammograms at facilities in the Breast Cancer https Surveillance Consortium. A little more than a third of the mammograms were digital. Kerlikowske says her study found that the two technologies are similar in women  to . If digital had been worse she says then wed be in trouble. Because radiologists can manipulate digital mammograms women who opt to begin screening in their s might choose digital mammography to optimize cancer detection in their denser breasts https the researchers write. The new studies appear in the Annals of Internal Medicine."