CORRESPONDENCE

Re: Trends in the Treatment of Ductal Carcinoma In Situ of the Breast

Mattia Intra, Nicole Rotmensz, Giuseppe Viale, Umberto Veronesi

Affiliations of authors: Division of Breast Surgery (MI,UV), Division of Epidemiology and Biostatistics (NR), European Institute of Oncology, Milan, Italy; University of Milan School of Medicine, Milan (GV)

Correspondence to: Mattia Intra, MD, Breast Surgery Division, European Institute of Oncology, Via Ripamonti, 435, 20141 Milan, Italy (e-mail: mattia.intra{at}ieo.it)

The treatment of ductal carcinoma in situ (DCIS) of the breast still represents a hotly debated issue, and wide variations in surgical management of DCIS have been recently reported (1). In particular, although the appropriateness of sentinel lymph node biopsy (SLNB) in the management of pure DCIS seems well established today because of the very low rate of axillary metastases and because its routine use is discouraged elsewhere (2,3), we were surprised that several authors continue to routinely perform SLNBs in all DCIS patients, without any distinction between different subhistotypes, tumor size, or tumor grade, reporting an overall high rate of metastatic lymph nodes in a small series of DCIS patients. We present our SLNB policy to try to resolve the open debate.

Between March 1, 1996, and June 30, 2003, 482 patients (between ages 30 and 80 years, average = 50.1 years) with pure DCIS (cases of DCIS with microinvasion were excluded) were subjected to SLNB, as described elsewhere (4,5). SLN metastases were detected in eight (1.7%) of these patients. The SLNs were the only affected nodes in the seven of these eight patients who subsequently underwent complete axillary lymph node dissections. Five of the eight SLN-positive patients had only micrometastases (<2 mm in diameter). Unfortunately, the low number of SLN-positive patients and the subsequent imbalance in the two groups make any kind of comparison between the two groups impossible. In particular, the risk of lymph node metastases does not seem to be associated with clinical presentation, grade, sex hormone receptor status, proliferative index (Ki-67), or type of surgery (Table 1). Only tumor size and a comedocarcinoma subhistotype appear to be relevant in predicting the risk of SLN metastases.


View this table:
[in this window]
[in a new window]
 
Table 1. Main histopathologic characteristics of 482 ductal carcinoma in situ (DCIS) tumors

 
Six (75.0%) of the eight patients with a metastatic SLN had undergone a previous breast biopsy examination (two, an open surgical biopsy, and four, a vacuum-assisted biopsy). In two of the latter four patients, an artifactual dislocation of tumor cells within the stroma along the needle track was identified. Only 58.6% of SLN-negative patients had previously undergone an invasive diagnostic procedure. The chance of passively transporting dislocated epithelial cells to the SLN during an invasive preoperative procedure has been reported, but it is still a hotly debated issue and has unresolved clinical implications (6). Although a preoperative invasive procedure might remove or hide microinvasive foci in the sampled DCIS, after 41 months of follow-up, no locoregional or systemic event has been observed in the eight SLN-positive patients.

In conclusion, because of the low prevalence of metastatic involvement (1.7%), SLNB should not be considered a standard procedure in the treatment of all patients with DCIS. In pure noncomedo DCIS completely excised by radical surgery with free margins of resection, SLNB should be avoided not only because it is unnecessary but also because it could jeopardize later SLNBs required if invasive disease recurs. An extensive and accurate histologic examination of the DCIS tumor is compulsory to exclude microinvasive foci that are, in fact, responsible for axillary lymph node metastases. SLNB should be considered in patients with DCIS where there is strong doubt that an invasive component can be detected from the definitive histologic examination, such as large solid tumors or diffuse or multicentric microcalcifications. In any case, if a total mastectomy is performed, SLNB is mandatory. In fact, it could not be successfully done if an invasive carcinoma is shown in the final histologic examination of the entire breast. Moreover, if the trend is statistically significantly confirmed in a wider population, patients with large-comedo DCIS, who have a high risk of SLN metastasis, should be scheduled for SLNB. If the SLNB detects micrometastases, a complete axillary dissection is not always unavoidable.

REFERENCES

1 Baxter NN, Virnig BA, Durham SB, Tuttle TM. Trends in the treatment of ductal carcinoma in situ of the breast. J Natl Cancer Inst 2004;96:443–8.[Abstract/Free Full Text]

2 Burstein HJ, Polyak K, Wong JS, Lester SC, Kaelin CM. Ductal carcinoma in situ of the breast. N Engl J Med 2004;350:1430–41.[Free Full Text]

3 Lagios MD, Silverstein MJ. Sentinel node biopsy for patients with DCIS: a dangerous and unwarranted direction. Ann Surg Oncol 2001;8:275–7.[Free Full Text]

4 Intra M, Veronesi P, Mazzarol G, Galimberti V, Luini A, Sacchini V, et al. Axillary sentinel lymph node biopsy in patients with pure ductal carcinoma in situ of the breast. Arch Surg 2003;138:309–13.[Abstract/Free Full Text]

5 Veronesi U, Paganelli G, Viale G, Luini A, Zurrida S, Galimberti V et al. A randomized comparison of sentinel-node biopsy with routine axillary dissection in breast cancer. N Engl J Med 2003;349:546–53.[Abstract/Free Full Text]

6 Carter BA, Jensen RA, Simpson JF, Page DL. Benign transport of breast epithelium into axillary lymph nodes after biopsy. Am J Clin Pathol 2000;113:259–65.[CrossRef][ISI][Medline]


This article has been cited by other articles in HighWire Press-hosted journals:


             
Copyright © 2004 Oxford University Press (unless otherwise stated)
Oxford University Press Privacy Policy and Legal Statement