"For women older than  who have been confused by conflicting advice on how frequently to get a mammogram some new science is here to guide their decisions. An ambitious research effort published http Monday in the Annals of Internal Medicine set out to tailor womens breast cancer screening practices to match their actual risk of breast cancer. It concludes that a womans breast density should influence the frequency with which she is screened for breast cancer in addition to such longrecognized breast cancer risk factors as age ethnicity personal history of abnormal breast findings and a family history of breast cancer. For a small slice of those women that makes a onceayear mammogram  twice as often as the current standard  the best bet. Underwritten by the National Cancer Institute the new study combined the datacollection efforts of breastcancer epidemiologists with three separate teams of cancer modelers. In the study women were separated into subcategories based on four levels each of individual risk and breast density. New research suggests womens breast cancer screening practices should match their actual risk of breast cancer.  The research recommends that women older than  with dense breast tissue who have higherthannormal risk of developing breast cancer should get annual mammograms. These women however represent a small minority of women in that age group  less than  of all women between  and . Many women however could go as long as three years between mammograms without increasing their risk of death from breast cancer the study found. For women with average risk and low breast density the models showed that there was no difference in deaths averted from breast cancer whether they were screened every two years or every three years. Women who had a mammogram every three years however had fewer unnecessary followup procedures including biopsies. Accepted clinical guidelines recommend that women  to  get a mammogram every two years. These recommendations first proposed in  by a federal task force urged women to discuss with their physicians whether more frequent screening might be in order. But they have continued to be controversial with some activist and medical groups that believe additional lives could be saved if more women got an annual mammogram. The latest study largely validates the controversial recommendations made by the U.S. Preventive Services Task Force in . But it also clarifies which women should or could depart safely from its recommendations. Only in the last decade or so have radiologists oncologists and womens health specialists begun to appreciate the role of breast density in a womans breast cancer risk. While radiologists have long warned that dense breast tissue made cancerous masses harder to spot mounting evidence has found that cancer is also more likely to gain a foothold in dense breast tissue. The latest effort is the first to produce a risk calculator httptools.bcscscc.orgBCyearRiskcalculator.htm that takes that into account and asks for a radiologists standardized assessment of breast density in its sixpoint questionnaire. Many states now require radiologists reading mammograms to assign and communicate to a woman and her physician this density measure called a Breast Imaging Reporting and Data System or BIRADS score. Overall the risk measure calculates a womans likelihood of developing breast cancer over five and  years and compares it to normal risk. In devising their models the researchers updated assumptions that have cast doubt on the relevance of existing breastcancer risk calculators which relied on the experiences of women who got an earlier generation of screening mammograms and were more likely to die of breast cancer than is currently the case. Here teams of modelers from Erasmus University in the Netherlands Albert Einstein College of Medicine in New York and Harvard Pilgrim Healthcare assumed that women were getting digital mammograms which offer improved cancer detection rates at lower radiation dosages than earlier mammographic methods. They took into account improved rates of breast cancer treatment effectiveness and changing causes of mortality for women older than . They also took account of the fact that breast density decreases in older women. These models are very applicable to the populations we screen said  UC San Francisco breastcancer specialist Dr. Karla Kerlikowske one of the lead authors of the new study. The practice of tailoring screening intervals to a womans breast cancer risk is already widespread in some European countries including Sweden the Netherlands and Spain. A Spanish study similar to the latest modeling effort found that implementing a general threeyear screening interval with yearly screening for highrisk women reduced overdiagnosis and caught more missed cancers. Some lesions detected in screening will never grow to become clinically significant and will not impact a womans life Kerlikowske said."