Mammograms detect few cancers in women under the age of 40 but cause expense and anxiety because women frequently get "false positives" that require follow-up to rule out cancer, researchers reported. Mammograms did not detect any tumors among women under the age of 25, the researchers reported in the Journal of the National Cancer Institute. The study of more than 117,000 U.S. women may reinforce controversial recommendations about the use of mammograms to screen for breast cancer among younger women.
