Chat discussion / DCIS article from 2004

[AlaskaAngel]

This article from 2004 is posted for those interested in DCIS during tonight's chat (1/8/06):


Treatment of ductal carcinoma in situ of the breast varies widely in U.S.

Megan Rauscher
Reuters Health
Posting Date: March 22, 2004

Last Updated: 2004-03-22 16:00:19 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Results of a study suggest that there are wide variations in the clinical management of women with ductal carcinoma in situ (DCIS) in the U.S. Some women, it appears from the study, are overtreated with aggressive surgical therapy including mastectomy and axillary dissection, while others are undertreated, receiving no radiation after lumpectomy.

Dr. Nancy N. Baxter of the University of Minnesota in Minneapolis and colleagues looked at the incidence and patterns of care for some 25,000 women diagnosed with DCIS from 1992 to 1999. The women were part of National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) cancer registry. The findings are published in the March 17th issue of the Journal of the National Cancer Institute.

According to Dr. Baxter, there was a "dramatic change" in the incidence of DCIS of the breast over the 8 years of observation, with a 73% increase in the number of cases detected. "This is likely due to improved detection of DCIS using mammography," she said.

There were also profound changes in some aspects of care over this relatively short period of time. Overall, the treatment for DCIS has become "less aggressive, likely reflecting better knowledge regarding the effectiveness of breast conserving therapy for DCIS and increasing familiarity with breast conserving therapy," Dr. Baxter told Reuters Health.

Nonetheless, some women still received aggressive care (mastectomy and axillary dissection) in 1999. In many cases, this was "likely clinically necessary, for example with extensive DCIS," Dr. Baxter said. "However, the wide variation in the rate of these procedures between geographical regions and based on patient demographics indicates that clinical necessity was not the only influential factor," she noted.

Overall, the rates of mastectomy and axillary dissection for DCIS declined, from 43% to 28% and from 34% to 15%, respectively. "Surprisingly," however, the rate of axillary dissection was still high (30%) in patients undergoing mastectomy in 1999, Dr. Baxter said. "DCIS is premalignant and therefore will not have spread to the lymph nodes so axillary dissection is not recommended," she said.

Another concern, Dr. Baxter said, is that only about half of the 64% of women who had breast-conserving lumpectomy received radiation afterward (45% in 1992 and 54% in 1999), "despite the publication of a randomized controlled trial demonstrating a benefit of radiation after lumpectomy during the study period."

"Even in patients with DCIS with comedo histology - a marker of more aggressive behavior - 33% did not undergo radiation after lumpectomy," Dr. Baxter reported.

In an editorial in the journal, Dr. Monica Morrow of NorthwesternUniversity's LynnSageBreastCenter in Chicago notes that part of the problem is the difficulty in predicting which women with DCIS will develop invasive cancer.

At present, "the treatment of DCIS is more properly considered the prevention of invasive carcinoma," she writes. "As with any prevention intervention, the individual's values, desires, and perceptions of what constitutes an acceptable level of risk should be the primary determinants of the prevention strategy used."

J Natl Cancer Inst 2004;98:424-425,443-448.