WEDNESDAY, Sept. 22 (HealthDay News) -- Routine mammograms account for only about one-third of the decline in breast cancer death rates, according to a large new analysis of data from Norway's expansive breast cancer screening program.
The other two-thirds of the reduction is probably due to such factors as increased cancer awareness, improved therapy and use of more sensitive diagnostic tools, the study authors suggest.
The analysis, published in the Sept. 23 issue of the New England Journal of Medicine, raises new questions about the benefits versus risks of screening mammography and is already reigniting tensions over its frequency of use in the United States.
"Women should be informed that the benefit is smaller than expected, and there should be a balanced discussion on the benefit and the possible harms of screening, such as overdiagnosis, false-negative and -positive tests and psychological distress," said the study's lead author, Dr. Mette Kalager, an epidemiologist with the Cancer Registry of Norway in Oslo and a visiting scientist at the Harvard School of Public Health in Boston.
"This study will only add to the confusion for women and their physicians," said Dr. Daniel B. Kopans, director of breast imaging at Massachusetts General Hospital and a radiology professor at Harvard Medical School.
Last November, the U.S. Preventive Services Task Force spurred dissension among breast cancer experts with controversial new guidelines for breast cancer screening. The task force recommended that women begin having screening mammograms at age 50 -- not 40 -- and that those exams occur every other year, instead of annually.
But some cancer organizations reject the panel's advice. The American Cancer Society still recommends annual mammograms starting at age 40, as long as a woman is still in good health.
On Tuesday, the American College of R
All rights reserved