"Mammography is especially likely to miss the [aggressive] tumors that do the most harm."
Of 429 breast cancers diagnosed over five years in Puget Sound, 279 were picked up by mammography, and most were in the earliest stage. Of the 150 that were missed, most were so fast growing that, although they didn't exist at the time of one yearly mammogram, they had progressed to lymph-node-involvement before the next yearly mammogram.
"The Picture Problem" Malcolm Gladwell, The New Yorker, December 13, 2004.
"The risks associated with over-diagnosis and over-treatment are significant enough to make avoiding mammography a reasonable choice for women without breast symptoms."
After screening mammography was begun in Norway, breast cancer diagnosis increased by 54%. In Sweden the increase was 45%. There has been no corresponding long-term reduction in the rate of women diagnosed. "The significance of these findings is this: Mammography causes many women to be diagnosed and treated for a type of breast cancer that would never produce symptoms or become life threatening if left undetected."
"Breast Screening Finds Many Cancers That Would Never be Lethal." HealthFacts from the Center for Medical Consumers, April 2004.
"There are certain calcifications ... that are always benign ... [and some that] are always associated with cancer. But ... the vast amount are in the middle and making that differentiation ... is not clear cut." David Dershaw, head of breast-imaging, Memorial Sloan Kettering.
Computer-aided mammograms may improve the doctors' bottom line, but they do nothing for women. A medical practice that does 60,000 mammograms would generate more than $650,000 in extra income by adding computer-aided detection, but this would cause "no discernible improvement in accuracy nor improved outcomes for the women screened."
"Computer-Aided Mammography No Improvement Over Standard Mammography," Health Facts from the Center for Medical Consumers, March 2004. A review of a report in the Journal of the National Cancer Institute, Feb. 4, 2004.
"During screening, 5 to 10 percent of mammograms show potential abnormalities, requiring doctors to order additional mammograms, ultrasound imaging, biopsies, and other tests. However, about 97 percent of women in their 40s and about 86 percent of women age 50 and over who have a suspicious initial mammogram turn out not to have breast cancer."
A prestigious group that independently evaluates the quality of evidence on medical-screening topics (PDQ) says its most recent review raises uncertainty about whether there's a benefit to mammogram screening. The PDQ report is at www.nci.nih.gov/cancertopics/pdq/screening/breast/healthprofessional
"Mammograms on Trial", Damaris Christensen, Science News, April 27, 2002
