Along with the change of terminology has come a call for more watchful waiting, an option that recently has been recommended and used for prostate cancer. Would the same approach be useful -- and safe -- for DCIS?
There is, by no means, agreement on this issue. Even though ductal carcinoma in situ is non-invasive, the risk should not be minimized, some say. These are abnormal growths with many of the same traits as invasive cancer cells. A significant number -- 20 to 40 percent -- develop into cancer, and women who have one or more lesions often develop invasive cancers elsewhere.
At this time, there is no certain way of telling which growths are potentially harmful and which are not. As a result, virtually all cases of DCIS are treated, usually with breast-conserving lumpectomy, sometimes followed by radiation therapy. Some patients, however, choose mastectomy, removal of one or even both breasts.
DCIS is rarely discovered as a lump. In 1980, before the advent of widespread mammography screening, these lesions represented only about one percent of all breast cancers. As mammography has become more widely used and more sensitive, DCIS diagnoses have increased rapidly.
These are small cancers detected early; and when DCIS is treated, survival is virtually 100 percent. But there is still uncertainty regarding how aggressively these should be treated. Since 60 to 80 percent of these lesions are benign and will never progress to the stage of invasive cancer, doctors realize that overtreatment is common.
Even though 60,000 new DCIS cases are being treated each year, there has been no corresponding decrease in the rate of invasive breast cancer. This suggests that there has been little or no value in treating DCIS as if it were early cancer, according to Laura Esserman, M.D., M.B.A., co-author of an essay published in the Journal of the American Medical Association [2009;302:1685-1692].
A joint news release from the Susan G. Komen for the Cure and the College of American Pathologists addressed some of the controversy. Mammography screening is still important, they point out, and should not be avoided because of fear of unnecessary therapy. Women should rather take an active role at every step of the process. Know what questions to ask and be confident about your ability to weigh your own individual risks and benefits.
This information was submitted by Northeastern Vermont Regional Hospital in St. Johnsbury and is meant to complement, not replace, the advice and care you receive from your health care provider.