The American College of Radiology (ACR) and the Society of Breast Imaging (SBI) have responded with criticism to a study published in the April issue of the Annals of Internal Medicine that estimates that the rate of cancer overdiagnosis from mammograms is between 15% to 25%.
The study analyzed Norwegian mammography screening program data, finding that this percentage range translates to six to 10 women overdiagnosed and only one death prevented for every 2,500 women invited to be screened every two years for 10 years (AIM, April 2012, Vol. 156:7, pp. 491-499). The researchers based their findings on data with an average of 2.2 years of follow-up, ACR and SBI said.
The study's analysis is unsound, according to ACR and SBI.
"Their analysis is flawed, leading to an overestimate of overdiagnosis and thus invalid conclusions about the value of mammography," the two organizations said in a statement. "The truth is that the Norwegian screening program is too early in its inception, and there is too little follow-up, to draw conclusions about the effectiveness and side effects of mammography with any measurable confidence."
