[Sentinel node biopsy in breast cancer: techniques and indications].
Sentinel node biopsy (SNB) has proved to be a useful and accurate procedure for lymph node staging in breast cancer and melanoma and should be standard of care in the treatment of these tumors. In other malignancies (colon, rectum, stomach, esophagus, head and neck and thyroid, cervix uteri) it is still under investigation. SNB in breast cancer was accepted as a sole and reliable diagnostic method in breast cancer from the panel of distinguished experts at the 8th international conference of primary therapy of early breast cancer 2003 in St. Gallen. Combination of the current techniques with radiocolloids and blue dye, applicated superficially (intradermal, subdermal, peri- and subareolar) and deeply (peritumoral, intratumoral, subtumoral) enables high identification rates and negative predictive values. It should be performed by teams consisting of surgeons, pathologists and nuclear medicine specialists with appropriate training and experience. Accepted indications are uni- and multifocal tumors smaller than 3 cm without suspicious findings in the axilla, furthermore SNB is indicated in patients with large ductal carcinoma in situ (>2cm) and/or with assumed microinvasion. Albeit SNB could be shown to be safe after preoperative chemotherapy and in multicentric breast cancer, due to lack of sufficient data it is still under discussion in these cases. Expedience of this procedure in other lymph node basins, along the mammaria interna vessels or in the infra- and supraclavicular region is considered to be at an investigative stage as well. SNB allows the pathologist to focus on a small number of nodes most likely to contain metastases. Application of serial sectioning and immunhistochemistry results in a more accurate staging than routine examination. Detection of additional micrometastases that are found in 10-15% leads to an upgrading from N0 to N1. Broad application and refurbishment led to scientific discussion of prognostic importance of micrometastases and its relevance according axillary dissection and adjuvant systemic treatment. Although many unicentric and multicentric observational studies validated by complete axillary dissection could demonstrate that SNB is accurate and suitable for all operable clinically node-negative breast cancers, longterm results and especially the incidence of axillary recurrence and its sequelae are outstanding. Findings of ongoing large prospective randomized trials like NSABP 32, Z0010 and Z0011 of the American College of Surgeons (ACOSOG), the AMAROS-Trial of the European Organisation of Research and Treatment of Cancer (EORTC) and the ALMANAC-Trial of the British Association of Surgical Oncology (BASO) will give a conclusive answer. Significant improvement in morbidity and quality of life measurements could be revealed several times in unicentric and even in muticentric studies like ALMANAC. Sentinel node biopsy is a team approach, requirements are good cooperation and well-defined stuctures of quality indicators and documentation. Participation in national clinical studies is recommended.
Haid
Anton
A
Abteilung für Allgemein- und Thoraxchirurgie am Landeskrankenhaus Feldkirch, Feldkirch. anton.haid@cable.vol.at
Knauer
Michael
M
Köberle-Wührer
Roswitha
R
Wenzl
Etienne
E
D001943:Breast Neoplasms / Q000473:pathology*; D002986:Clinical Trials as Topic; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D009367:Neoplasm Staging / Q000379:methods*; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians'; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*