Treatment of ductal carcinoma in situ (DCIS), a group of abnormal cells confined to the breast ducts, varies widely in the United States. Treatment ranges from potential over-treatment with aggressive surgical therapy to possible under-treatment by not providing radiation.
In the absence of data that allow identification of women with DCIS who are at risk for invasive recurrence of their cancer, understanding who makes treatment decisions and why is more likely to do more to improve the care of women with DCIS than any treatment guidelines, said breast cancer surgeon Monica Morrow, M.D.
“Evidence suggests that the critical difference between the prevention goal of DCIS treatment and the therapeutic goal of invasive cancer management is not well appreciated by women with the disease,” said Morrow, professor of surgery at the Feinberg School of Medicine at Northwestern University.
Morrow is also director of the Lynn Sage Comprehensive Breast Program at Northwestern Memorial Hospital and a researcher at The Robert H. Lurie Comprehensive Cancer Center of Northwestern University.
Morrow said that until the genetic changes that govern the progression from in situ to invasive disease are identified, a better understanding of how to communicate what is and is not known about the nature of DCIS and a better understanding of patient preferences and factors that influence the decision-making process are critical to helping women make decisions that meet their needs.
Morrow commented on a University of Minnesota study that appeared in an issue of the JNCI. That study, which examined data from the Surveillance, Epidemiology, and End Results program for over 25,000 women diagnosed with DCIS from 1992 to 1999, found that the number of cases of DCIS increased 73 percent during the study period.
Overall, almost 98 percent of patients had some type of surgery. The proportion of patients who had a mastectomy declined from 43 percent to 28 percent during the study period.
Overall, 64 percent of women with DCIS had breast-conserving surgery. In 1992, 45 percent of the patients who had breast-conserving surgery received radiation therapy, compared with 54 percent in 1999. The use of axillary dissection overall -- the removal of the lymph nodes in the armpit to test for possible spread of disease -- declined from 34 percent in 1992 to 15 percent in 1999.
Among women who had a mastectomy over the entire study period, 42 percent also had axillary dissection, even though this procedure was not routinely recommended during the study period. Both radiation therapy and axillary dissection were more common among women whose DCIS had more aggressive characteristics.