A new study has found that 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 overtreatment with aggressive surgical therapy to possible undertreatment by not providing radiation therapy after breast-conserving surgery, according to the study, which is published in the March 17 issue of the Journal of the National Cancer Institute.
The incidence of DCIS has increased dramatically in the last few decades, largely because of increased rates of screening mammography. In some cases, DCIS can progress to invasive cancer, but little is known about the characteristics that determine whether or not DCIS will progress to cancer.
To examine current patterns of care of DCIS, Nancy Baxter, M.D., Ph.D., of the University of Minnesota, and colleagues examined data from the Surveillance, Epidemiology, and End Results program for 25,206 women diagnosed with DCIS from 1992 to 1999. They found that the number of cases of DCIS increased 73% during the study period. Overall, 97.5% of patients had some type of surgery. The proportion of patients who had a mastectomy declined from 43% to 28% during the study period.
Overall, 64% of women with DCIS had breast-conserving surgery. In 1992, 45% of the patients who had breast-conserving surgery received radiation therapy, compared with 54% 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% in 1992 to 15% in 1999. Among women who had a mastectomy over the entire study period, 42% 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.
"According to our study, many patients apparently underwent aggressive surgical treatment for DCIS," the authors write. "Yet other patients appear to have been undertreated, with no radiation therapy after lumpectomy for almost half of them, even in many patients with adverse risk factors. … We believe that heightened awareness and establishment of standard treatment recommendations could improve DCIS treatment."
In an editorial, Monica Morrow, M.D., of Northwestern University's Lynn Sage Breast Center in Chicago, discusses some of the characteristics of DCIS that make it difficult to treat, such as the often large size and the wide variation in recurrence rates. "The ability to predict which women with DCIS will develop invasive cancer will ultimate solve the dilemma of DCIS," Morrow writes. "For the present, understanding who makes treatment decisions and why is likely to do more to improve the care of women with DCIS than any treatment guidelines."
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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