The sentinel node dilemma in breast cancer surgery

(Press-News.org) Amsterdam, The Netherlands, April 12, 2011 – The sentinel node (SN) procedure in breast cancer is based on the premise that if the first node into which breast tissue drains is clean, the remaining lymph nodes in the armpit are likely not involved, with no need for removal. This was developed to limit surgical overtreatment and reduce morbidities such as blockage of lymph vessels and shoulder dysfunction. However, in the initial years of the SN procedure, surgeries actually increased when isolated tumor cells were found. A special issue of Breast Disease presents an insightful overview of the Sentinel Node procedure.

"An increasing amount of evidence is becoming available on nodal isolated tumor cells and micrometastases since the introduction of the SN procedure," commented the issue's Guest Editor, Prof. Dr. Vivianne C.G. Tjan-Heijnen, Chair Oncology Committee MUMC, Head Division Medical Oncology, Maastricht University Medical Centre, Maastricht, The Netherlands. "Data on a number of randomized studies are expected in the next few years. To this end, this issue of Breast Disease provides an overview of current evidence that may be supportive in making the best decision in current patient care."

The introduction of population-based breast cancer screening and an increased awareness in the general population regarding breast lumps has resulted in a shift towards clinically node-negative breast cancer stages. Today, about 60% of breast cancer patients have pathologically node-negative disease.

### CONTENTS & KEY POINTS: Editorial: The Breast Cancer Sentinel Node Dilemma: What to Do with Isolated Tumor Cells and Micrometastases?
Vivianne C.G. Tjan-Heijnen
This introduction to the issue summarizes current thinking on treating patients in whom isolated tumor cells or micrometastases are detected.

Pathology Issues Related to SN Procedures and Increased Detection of Micrometastases and Isolated Tumor Cells
Paul J. van Diest, Carolien H.M. van Deurzen and Gábor Cserni
The authors provide an up-to-date discussion on the virtues and flaws of different methods to find SN metastases, and provide recommendations on the optimal pathology protocol for breast cancer SNs and the best way to classify small nodal metastases.

Axillary Recurrences Following Positive Sentinel Lymph Node Biopsy with Individual Tumor Cells or Micrometastases and No Axillary Dissection
Kathleen M. Erb, Hilary M. Shapiro-Wright and Thomas B. Julian
This study provides an overview concerning axillary recurrence rates following a positive SN. For the present, axillary lymph node dissection for SN micrometastasis is still recommended for most patients. However, for selected patients, after weighing the risks and the benefits of additional axillary treatment by a multidisciplinary team, additional axillary treatment could be omitted.

Can Radiotherapy Replace Axillary Dissection for Patients with Positive Sentinel Nodes?
Abram Recht
This article examines radiotherapy of patients with positive sentinel node biopsy, the limited data on outcome of patients with a positive sentinel node biopsy who do not undergo completion dissection, and the toxicities of axillary irradiation. The author concludes that until further studies provide clarity, surgical intervention is still recommended.

Prediction of Non-SN Involvement in Patients with SN Isolated Tumor Cells or Micrometastases
Catherine Pesce, Charles Balch and Lisa Jacobs
The authors provide an overview of published studies regarding prediction of non-SN involvement. These studies show that not only the size of SN involvement, but also primary tumor characteristics play a role, such as primary tumor size and presence or absence of lymphovascular invasion. However, none of these studies have reliably identified a patient population at sufficiently low risk for axillary nodal metastases to avoid axillary treatment.

Prognostic Impact Of Isolated Tumor Cells and Micrometastases in Axillary Lymph Nodes of Breast Cancer Patients
Vivianne C.G. Tjan-Heijnen, Manon J. Pepels and Maaike de Boer
Having reviewed the literature on the prognostic impact of isolated tumor cells and micrometastases in early stage breast cancer patients, the authors conclude that the presence of isolated tumor cells or micrometastases is associated with a hazard ratio of about 1.50 for disease events compared to node-negative disease.

These articles appear in Breast Disease, Volume 31, Number 2, published by IOS Press.
Nodal Micrometastases or Isolated Tumor Cells and the Outcome of Breast Cancer
Guest Editor: Vivianne C.G. Tjan-Heijnen, Maastricht University Medical Centre, Division of Medical Oncology, Maastricht, The Netherlands