Axillary Surgery in DCIS: Is Less More?

As our understanding of the biology of ductal carcinoma in situ (DCIS) has increased, the management approach to the axilla has evolved. DCIS, by definition, cannot metastasize, and it has been known for many years that nodal metastases, presumed to be due to unrecognized invasion, are extremely uncommon. In a National Cancer Database review of 10,946 patients with DCIS undergoing axillary dissection between 1985 and 1991, only 3.6% were found to have axillary metastases, and this number is even lower when only cases of screen-detected DCIS are considered. The major impetus for nodal staging in DCIS today is the recognized sampling error that occurs when needle biopsy techniques are used for diagnosis. In 1998, a joint committee of the American College of Surgeons, American College of Radiologists, and College of American Pathologists developed a standard for the diagnosis and management of DCIS which concluded that axillary dissection was unnecessary for the majority of patients with DCIS. Consideration of a level I dissection to avoid a second surgical procedure for patients undergoing mastectomy for extensive or high-grade DCIS was recommended. When these guidelines were updated in 1992, they reflected both the emergence of sentinel node biopsy as an axillary staging technique and the low likelihood of identifying invasive carcinoma with nodal disease in localized DCIS by recommending that axillary staging in patients treated with breastconserving approaches be reserved for those found to have invasion on final pathologic evaluation. In patients undergoing mastectomy, sentinel node biopsy for axillary staging was recommended for surgeons experienced in the technique; for those who were not, a level I axillary dissection was suggested. In this issue of the Annals of Surgical Oncology, Porembka et al. use Surveillance, Epidemiology, and End Results (SEER) data from 1988 through 2002 to analyze axillary management in patients with DCIS. Based on their analysis of 23,502 patients, they conclude that there is persistent and excessive utilization of axillary nodal assessment, particularly axillary dissection, in patients with DCIS. The data as presented is alarming, with 21% of those having surgery between 1998 and 2002 undergoing lymph node assessment. In the group that had breast-conserving surgery (BCS), 67% of the nodal procedures were axillary dissections; in the mastectomy group, 87% had axillary dissection. There are several important caveats to these observations. First, the SEER database, while an excellent source of high-quality, population-based cancer data, may not be an ideal source for analyzing the nuances of axillary surgery. SEER coding rules state that, if axillary nodes are present in a mastectomy specimen, the procedure should be coded as a modified radical mastectomy rather than a simple mastectomy. The removal of a few level 1 axillary nodes in order to ensure removal of the axillary tail of the breast is not uncommon, and certainly does not constitute a therapeutic axillary dissection, although it would be coded as such by SEER rules. Thus, the most accurate assessment of the use of axillary dissection is obtained from the subset of women undergoing BCS. Based on the authors’ statement that 70% of the 10,637 women treated in the 1998–2002 timeperiod hadBCS, and that 589 had axillary staging, this results in about 395 axillary dissections, or 5% of the total group. The second major issue regarding this work is that the time period under study was the same time period in which the sentinel node biopsy technique was being validated, refined, and disseminated. Two major Published online August 5, 2008. Address correspondence and reprint requests to: Monica Morrow, MD; E-mail: morrowm@mskcc.org