What I need is the result of the ACOSOG Z0011 trial ! Which is still going on.

The ACOSOG Z0011 trial is a prospective study that randomizes patients with a positive SLN biopsy to either completion axillary dissection or no further surgery


Preliminary Outcome Analysis in Patients With Breast Cancer and a Positive Sentinel Lymph Node Who Declined Axillary Dissection

The arguments that suggest that it may be appropriate to avoid completion dissection fall into the following categories:
.
(1) the incidence of positive nonsentinel nodes is low for micrometastasis,
(2) the adjuvant chemotherapy is likely to destroy any microscopic involvement,
(3) information obtained from completion axillary dissection rarely alters treatment recommendations,
(4) there is no conclusive evidence that immediate dissection is better than observation and delayed dissection if metastatic growth in the axilla is subsequently noted.

Hmm.. an interesting info from this article:

There was a low incidence of positive nonsentinel nodes in patients with micrometastasis (ductal, 0%; lobular, 31%) compared with macrometastasis (ductal, 29%; lobular, 75%). Likewise, Chu et al.12 reported a 7% rate of further disease in the axilla when the SLN had a <2-mm focus of tumor and 55% if a >2-mm focus of tumor was identified. Kamath et al.,13 in evaluating SLN micrometastasis alone, found a 15% risk of residual disease.
.
Next, adjuvant chemotherapy may contribute to the locoregional control of axillary metastases. Furukawa et al.14 evaluated the response of lymph node metastasis to various chemotherapeutic agents and found that nodal tumor was chemosensitive. It has also been shown that patients with a primary tumor response to neoadjuvant chemotherapy are less likely to have nodal metastasis at surgery.15,16 Fisher et al.,17 in reviewing data from National Surgical Adjuvant Breast and Bowel Project B-18, found 36% of clinically node-positive patients were pathologically node negative after receiving neoadjuvant chemotherapy. Together, these studies suggest that chemotherapy is likely to ablate residual microscopic axillary metastases.

Also, information obtained from completion axillary dissection may not change the patient’s treatment. Baxter et al.18 have shown that most patients with invasive breast cancer undergo adjuvant systemic therapy regardless of axillary node status, a finding supported by the data of Fisher et al.19 and discussed by Singletary20 in her review of systemic treatment after SLN biopsy. Miltenburg et al.,21 in their meta-analysis of SLN biopsy in breast cancer, question the therapeutic benefit of total level I and II lymph node removal, estimating that 70 of 100 axillas will not contain cancer.

Limited information is available regarding the outcome of patients with positive sentinel node resection and observation after adjuvant therapy. The data presented in this study suggest that SLN biopsy without axillary dissection may be an acceptable alternative to completion axillary dissection. However, longer follow-up and prospective randomized studies are needed to delineate appropriate criteria for patient selection and confirm the safety of this approach. Patients should be encouraged to enroll in ACOSOG Z0011, which randomizes to completion dissection or no further surgery. On the basis of the preliminary results of this study, the latter approach is both ethical and justifiable.