Experience with lymphatic mapping in breast cancer using isosulfan blue dye

Histologic evaluation of sentinel and non-sentinel axillary lymph nodes in breast cancer by multilevel sectioning and predictors of non-sentinel metastasis

Sentinel lymph node (SLN) provides accurate nodal staging for breast cancer. This technique has been introduced in Siriraj Hospital since 1998. The goal of this study is to assess its accuracy in predicting the state of the axilla, and compare the results of standard examination and multilevel sectioning. A retrospective analysis of 195 breast cancer patients who underwent both SLN biopsy (using dye alone as the lymphatic mapping) and axillary node dissection during 1998-2002 were analyzed. All slides including SLNs and the non-SLNs (NSLNs) were reviewed and multilevel study was performed on all SLNs and NSLNs [four levels of hematoxylin-eosin (HE) at 200 µm interval and keratin stains on the first and fourth levels]. Of 195 patients, 30% of cases were SLN-positive (32 NSLN-positive and 27 NSLN-negative). Additional study could detect positive axillary nodes 10.8% (4 SLN-positive and 5 NSLN-positive) more than standard HE stain. The false negative rate increased from 20.3% to 24.1%. The concordance between SLN and NSLN statuses was 89.7%. The sensitivity was 75.9%. By multivariate analysis, the significant predictors for axillary node metastasis were tumor size of more than 2.2 cm, histologic type of invasive ductal carcinoma (IDC), not otherwise specified (NOS) and lymphovascular invasion (LVI). By univariable analysis, the significant predictors of NSLN metastasis after positive-SLN were outer location of the tumor, LVI and perinodal extension. In conclusion, use of multilevel and immunohistochemistry increased detection of positive-SLNs. Caution should be kept in accepting SLN biopsy using peritumoral dye technique alone as the procedure for staging due to a high false-negative rate. The concordance rate of 89.7% confirmed the reliability of SLN. Outer location of tumor, LVI and perinodal extension is significant predictors of positive-NSLN after positive-SLN.

The false-negative rate of sentinel node biopsy in patients with breast cancer: a meta-analysis

BACKGROUND

In sentinel node surgery for breast cancer, procedural accuracy is assessed by calculating the false-negative rate. It is important to measure this since there are potential adverse outcomes from missing node metastases. We performed a meta-analysis of published data to assess which method has achieved the lowest false-negative rate.

METHODS

We found 3,588 articles concerning sentinel nodes and breast cancer published from 1993 through mid-2011; 183 articles met our inclusion criteria. The studies described in these 183 articles included a total of 9,306 patients. We grouped the studies by injection material and injection location. The false-negative rates were analyzed according to these groupings and also by the year in which the articles were published.

RESULTS

There was significant variation related to injection material. The use of blue dye alone was associated with the highest false-negative rate. Inclusion of a radioactive tracer along with blue dye resulted in a significantly lower false-negative rate. Although there were variations in the false-negative rate according to injection location, none were significant.

CONCLUSIONS

The use of blue dye should be accompanied by a radioactive tracer to achieve a significantly lower false-negative rate. Location of injection did not have a significant impact on the false-negative rate. Given the limitations of acquiring appropriate data, the false-negative rate should not be used as a metric for training or quality control.

Lymphatic mapping and sentinel lymph node biopsy in early-stage breast carcinoma: a metaanalysis

BACKGROUND

Lymphatic mapping with sentinel lymph node biopsy has the potential for reducing the morbidity associated with breast carcinoma staging. It has become a widely used technology despite limited data from controlled clinical trials.

METHODS

A systematic review of the world's literature of sentinel lymph node (SLN) biopsy in patients with early-stage breast carcinoma was undertaken by using electronic and hand searching techniques. Only studies that incorporated full axillary lymph node dissection (ALND), regardless of SLN results, were included. Individual study results along with weighted summary measures were estimated using the Mantel-Haenszel method. The correlations of outcomes with the study size, the proportion of positive lymph nodes, the technique used, and the study quality were evaluated.

RESULTS

Between 1970 and 2003, 69 trials were reported that met eligibility criteria. Of the 8059 patients who were studied, 7765 patients (96%) had successfully mapped SLNs. The proportion of patients who had successfully mapped SLNs ranged from 41% to 100%, with > 50% of studies reporting a rate < 90%. Lymph node involvement was found in 3132 patients (42%) and ranged from 17% to 74% across studies. The false-negative rate (FNR) ranged from 0% to 29%, averaging 7.3% overall. Eleven trials (15.9%) reported an FNR of 0.0, whereas 26 trials (37.7%) reported an FNR > 10%. Significant inverse correlations were observed between the FNR and both the number of patients studied (r = - 0.42; P < 0.01) and the proportion of patients who had successfully mapped SLNs nodes (r = - 0.32; P = 0.009).

CONCLUSIONS

Lymphatic mapping with SLN biopsy is used widely to reduce the complications associated with ALND in patients with low-risk breast carcinoma. This systematic review revealed a wide variation in test performance.

Clinical aspects of sentinel node biopsy

Sentinel lymph node (SLN) biopsy requires validation by a backup axillary dissection in a defined series of cases before becoming standard practice, to establish individual and institutional success rates and the frequency of false negative results. At least 90% success in finding the SLN with no more than 5-10% false negative results is a reasonable goal for surgeons and institutions learning the technique. A combination of isotope and dye to map the SLN is probably superior to either method used alone, yet a wide variety of technical variations in the procedure have produced a striking similarity of results. Most breast cancer patients are suitable for SLN biopsy, and the large majority reported to date has had clinical stage T1-2N0 invasive breast cancers. SLN biopsy will play a growing role in patients having prophylactic mastectomy, and in those with 'high-risk' duct carcinoma in situ, microinvasive cancers, T3 disease, and neoadjuvant chemotherapy. SLN biopsy for the first time makes enhanced pathologic analysis of lymph nodes logistically feasible, at once allowing greater staging accuracy and less morbidity than standard methods. Retrospective data suggest that micrometastases identified in this way are prognostically significant, and prospective clinical trials now accruing promise a definitive answer to this issue.

Touch imprint cytological analysis of sentinel lymph nodes for detecting axillary metastases in patients with breast cancer

BACKGROUND

Sentinel lymph node biopsy is a procedure that examines the first tumour-draining lymph node. Touch imprint cytology may provide a quick method for intraoperative screening of sentinel lymph nodes for the presence of metastases.

METHODS

Touch imprint cytological analysis of sentinel lymph nodes was compared prospectively with the findings obtained on routine paraffin sections. Touch imprint slides from 55 patients with breast cancer were prepared during operation from multiple sections of sentinel lymph nodes, stained with haematoxylin and eosin. A cytopathologist blinded to the histological results interpreted the smears.

RESULTS

The concordance between touch imprint and paraffin sections of sentinel lymph nodes was 98 per cent (54 of 55). When touch imprint analysis of sentinel lymph nodes was compared with paraffin sectioning of all lymph nodes from the axillary node dissection, the concordance was 95 per cent (52 of 55). The sensitivity and specificity of sentinel lymph node touch imprints in detecting metastases were 82 and 100 per cent respectively. The positive and negative predictive values were 100 and 93 per cent respectively.

CONCLUSION

Touch imprint cytology is potentially useful for the intraoperative evaluation of sentinel lymph nodes in patients with breast cancer.