False-negative rates in sentinel-node in breast cancer

Técnica del ganglio centinela en la cirugía del cáncer de mama en un hospital sin servicio de medicina nuclear

INTRODUCTION

Knowledge of lymph node stage is the most important prognostic factor in breast cancer. The sentinel lymph node biopsy technique (SLNBT), initially developed to avoid unnecessary dissection in melanoma, has been shown to be able to predict the axillary stage of breast cancer. The difficulty of applying the SLNBT in hospitals without a nuclear medicine service has led to the existence of external teams that allow these hospitals to apply the technique.

OBJECTIVE

To test the application of the SLNBT in our hospital which has no nuclear medicine service.

PATIENTS AND METHODS

Coinciding with the validation of the SLNBT in the Germans Trias i Pujol Hospital in Badalona in November 1999, and with their help, the Centre Hospitalari de Manresa began to apply this technique. In 2002, the technique was used in all the hospitals of the ALTHAIA-Xarxa Assistencial de Manresa. From November 1999 to June 2005, the technique was applied in 163 patients.

RESULTS

Of the 163 patients, the technical success rate was 97.55%. In 98% of the patients, the sentinel lymph node was found in the axilla. In 10.7% of the patients, the node was found in the internal mammary basin. Twenty-six percent of the axillas had metastases of over 2 mm, and 16% had micrometastases. One hundred and five patients were spared axillary dissection.

CONCLUSIONS

The SLNBT can be performed in a hospital without a nuclear medicine service. This technique improves and simplifies the surgical technique and reduces length of hospital stay and morbidity.

Internal mammary sentinel node metastases in an otherwise lymph-node negative breast cancer patient

A 35 year old woman with biopsy proved breast cancer was submitted for sentinel node (SN) biopsy. Preoperative lymphoscintigraphy displayed both axillary and internal mammary (IM) uptake foci consistent with SNs. Full axillary dissection was completed because of a greater-than 2 cm primary lesion. Two axillary SNs were excised. An IM SN was also excised through the second intercostal space, with the aid of the gamma probe. Fourteen axillary nodes, including SNs, were negative, whereas the IM SN harbored several metastatic implants. Implications for staging, prognosis and further therapy of such IM-only positive sentinel nodes are discussed.

Sentinel node biopsy as a practical alternative to axillary lymph node dissection in breast cancer patients: an approach to its validity

BACKGROUND

Sentinel node biopsy (SNB) has been proposed as an alternative to axillary lymph-node dissection (ALND) in breast cancer. Before implementing SNB in our practice, we wished to test its validity by comparing it to the standard ALND, both in our hands and with other reported series.

PATIENTS AND METHODS

One hundred thirty-two patients were included prospectively. SNB and immediate ALND were performed. For SNB, a technetium-colloid was used to produce preoperative lymphoscintigraphy and intraoperative gamma-probe search for the SN. Serial sectioning and immunostains were used on the SN. A comprehensive review of the literature was done in order to run a meta-analysis of diagnostic tests using a summary receiver operating characteristic curve (SROC) to calculate the pooled parameters of sensitivity and associated 95% confidence interval (95% CI), including our own data.

RESULTS

Our technical success rate was 96%. Local sensitivity was 96%, with a 95% CI from 85%-99%. Seven patients were upstaged by the SNB. A literature search identified 18 studies published from 1996-1999. Estimates of sensitivity ranged from 83%-100%. The pooled data meta-analysis gave a global sensitivity of 91%, with a 95% CI from 89%-93%. The area under the global SROC curve was 0.9967.

CONCLUSIONS

The minimally invasive SNB was shown to be a practical alternative to ALND. We propose to use local as well as global sensitivity and associated 95% CI to test the validity of SNB in the clinical setting. Due to limitations of ALND as the golden standard, SNB can in fact be considered a more accurate method for nodal staging.