Breast cancer screening in women over 70 years of age may be leading to overdiagnosis and unnecessary invasive diagnostic procedures and treatments, according to a study in the September Annals of Internal Medicine. Researchers analyzed data from Medicare claims for breast cancer screening of over 54,000 women 70 years of age and older. They found that 31% of breast cancers found in women 70 to 74 years caused no symptoms and were unlikely to affect their health during their lifetimes. That proportion increased to 54% in women 85 years of age and older. Overdiagnosis increased as life expectancy decreased. The American Cancer Society recommends women continue screening if they have a life expectancy of 10 years or more, while the U.S. Preventive Services Task Force recommends biennial screening for women up to age 74 but cites insufficient evidence for screening women 75 years or older.