Mammograms Detect Cancers
Reported December 02, 2008
(Ivanhoe Newswire) — Can breast cancer disappear on its own?
A new Norwegian report finds some breast cancers detected on mammography may have gone away if they had not been found and treated.
The study looked at breast cancer rates among 119,472 women age 50 to 64. Participants had three screening mammograms between 1996 and 2001. Researchers compared them to a control group of 109,784 women age 50 to 64 in 1992, who did not have the screening. They tracked the cancers for six years then gave all participants a final mammogram.
Results show breast cancer rates were 22-percent higher in the group screened multiple times. 1,909 of every 100,000 women in the multiple-screened group had breast cancer compared to 1,564 of every 100,000 women in the group screened only once.
This raises the possibility that the natural course of some screen-detected invasive breast cancers is to spontaneously regress, write the authors. Although many clinicians may be skeptical of the idea, the excess incidence associated with repeated mammography demands that spontaneous regression be considered carefully.
Researchers say the results imply that as many as two out of three mammograms detected lesions that may be pseudo cancers.
SOURCE: Archives of Internal Medicine, 2008;168:2311-2316