Does Mammography Result in Overtreatment?
June 21, 2000 -- Although the majority of women in the U.S. appear to understand the importance of getting regular mammograms to detect breast cancer early, most don't know enough about the common abnormalities that mammograms can detect to make informed treatment decisions -- and their doctors should be telling them more about them, a survey suggests.
The most common type of breast abnormality detected by mammography is ductal carcinoma in situ (DCIS), a precancerous lesion that is confined to the milk ducts of the breast. Many women with DCIS will never develop cancer in their lifetime; others will, but doctors don't really know how to predict when cancer might occur and in whom. Therefore, the management and treatment of DCIS can be controversial.
Typically, when mammography shows a DCIS-like abnormality, physicians will do a biopsy to examine the lesion and confirm a diagnosis. Some doctors and patients will choose the "watch and wait" method -- checking the lesion every six months with mammography to see if it is progressing. But others will consider aggressive treatment that may include surgery, drug treatment with tamoxifen, or radiation.
In the June 17 issue of the British Medical Journal, researchers suggest that if only a small proportion of DCIS lesions ever progress to cancer, it raises questions about the possibility that many women will be overtreated, since mammography has such a high probability of detecting abnormalities. Co-author Steven Woloshin, MD, says the survey of 479 women that he and colleagues conducted suggests that most women don't know enough about DCIS to make informed decisions and that their doctors should be telling them more about it.
"It's a very difficult dilemma, and the issue is that, in our effort to find all cancers, inevitably we will pick up things in the 'gray' zone. For some of these people, we don't know if we are doing more harm than good," says Woloshin, who is assistant professor of medicine at the VA Medical Center in White River Junction, Vt.
But Anne Blackwood, MD, who reviewed the survey results for WebMD, says while it is important for women to have knowledge of DCIS and other abnormalities that can be detected on mammograms, she says fear of the mammogram detecting something should not deter women from getting their mammograms on time. Having a discussion about DCIS -- what it means and how it's treated -- is something that usually happens after a diagnosis is made, she says.