Intraoperative assessment of axillary lymph node metastases in operable breast cancer

President’s Address

In breast cancer surgery, there has been a major shift toward less invasive local treatment: from extended or radical mastectomy to modified radical mastectomy, from modified radical mastectomy to breast conserving therapy, and from routine axillary lymph node dissection to sentinel lymph node biopsy. Many breast surgeons have experienced an evolutionary progression of surgical management of breast cancer. However, there is an increasing demand for minimally invasive and non-surgical treatment methods for patients with small breast cancer. Radiofrequency (RF) ablation is the most promising among non-surgical ablation techniques in the treatment of breast cancer, although it is still in the investigative stage. Nevertheless, surgery still plays an integral role in the treatment of breast cancer, because local therapy is important for enhancing survival in the presence of systemic therapy. In clinical practice, surgical oncologists must individualize treatments, selecting a surgical or non-surgical procedure that provides the best local control, does not compromise the chances of cure, and achieves the best cosmetic results.

Sentinel lymph node biopsy in breast cancer: an overview of the Japanese experience

This paper reviews the Japanese literature regarding sentinel lymph node (SLN) biopsy in an attempt to provide an overview of existing controversies and to suggest a method for the identification of the SLN and the detection of micrometastases in the SLN to eliminate unnecessary axillary lymph node dissection (ALND). The combined dye- and gamma probe-guided method resulted in the accurate identification of the SLN in 96% of patients, compared with 80% when the dye-guided method alone was used. Although neither 99m-Tc sulfur colloid nor 99m-Tc colloidal albumin is commercially available in Japan, 99m-Tc stannous phytate and 99m-Tc rhenium colloid appear to be ideal tracers for identifying SLNs. Moreover, subdermal injection over the primary tumor or subareolar injection was found to enhance SLN identification, although these injection routes do not lead to detection of internal mammary SLNs. Furthermore, the accuracy of SLN diagnosis using frozen sections as well as imprint cytology improved with an increase in the number of sections, and could attain a sensitivity comparable to that obtained with routine histologic examination of permanent sections. As a result, several surgeons have begun to offer the option of forgoing ALND to patients with negative SLN. Although subsequent relapse in the axilla has not yet been reported, longer follow-up periods are needed to assess accurately the incidence of axillary failure in these negative SLN patients.

Frozen section investigation of the sentinel node in malignant melanoma and breast cancer

BACKGROUND

Intraoperative frozen section investigation allows immediate regional lymph node dissection when the sentinel node contains tumor. The purpose of this study was to determine the sensitivity of frozen section diagnosis of the sentinel node in melanoma and breast cancer patients.

METHODS

A total of 177 sentinel nodes from 99 melanoma patients and 444 lymph nodes from 262 breast cancer patients were assessed by frozen section investigation. Nodes were bisected, and a complete cross-section was obtained for frozen section. Step sections at three levels were made of the remaining lymphatic tissue and were stained with hematoxylin and eosin and S100/HMB45 (melanoma) or CAM5.2 (breast cancer) to obtain a final pathological diagnosis.

RESULTS

Frozen section investigation revealed metastases in 8 of 17 node-positive melanoma patients (47%). Seventy-one of 96 breast cancer patients (74%) with lymph node metastases were identified with frozen section. The specificity was 100% and 99%, respectively.

CONCLUSION

The sensitivity of intraoperative frozen section investigation of sentinel nodes was 47% in melanoma patients and 74% in breast cancer patients. Frozen section examination allows immediate axillary lymph node dissection in the majority of node-positive breast cancer patients. Frozen section analysis is not recommended in patients with melanoma.

The Role of Axillary Lymph Node Dissection in Breast Cancer Management

Although it is generally accepted that axillary dissection provides no survival advantage in patients with breast cancer, it is commonly regarded as a reliable method of assessing nodal status and treating regional disease. However, it is time to consider eliminating routine axillary dissection in patients who are clinically node-negative. A sentinel lymph node biopsy may assess axillary nodal status while obviating a full axillary dissection. At present, axillary dissection remains the standard approach for the surgical management of all patients with invasive carcinoma of the breast, regardless of tumor size or patient age, though it is unnecessary for patients with small intraductal carcinomas.

Diagnosis of axillary lymph node metastases in patients with breast cancer

The diagnosis of axillary (AX) metastases remains a challenge in the management of breast cancer and is a subject of controversy. Clinical node staging clearly is limited in the assessment of AX lymph nodes. AX mammography, ultrasonography, and computed tomography (CT) do not provide histologic information. Although nuclear magnetic resonance imaging may have considerable value in the diagnosis of AX metastases, it does not detect micrometastases. The use of biologic markers in the assessment of AX metastases remains a subject of investigation. On the other hand, biopsy of selected AX nodes or tissue with examination of histology or cytology generally would not identify a significant percentage of patients with AX node involvement. Sentinel lymph node biopsy, however, might be potentially useful for assessing AX metastases, although it remains investigational. In order to simplify diagnosis and reduce morbidity and mortality, alternatives to AX dissection must be sought and imaging and staging modalities refined. We present a review of the literature pertaining to the diagnosis of AX metastases in patients with breast cancer and a discussion of some current areas of controversy.