Sentinel Node Biopsy in Ductal Carcinoma In Situ Patients

Abstract

This study confirms that lymphatic mapping in breast cancer patients with DCIS lesions is a technically feasible and a highly accurate method of staging patients with undetected micrometastatic disease to the regional lymphatic basin. This procedure can be performed with minimal morbidity, because only one or two SLNs, which are at highest risk for containing metastatic disease, are removed. This allows the pathologist to examine the one or two lymph nodes with greater detail by using serial sectioning and CK IHC staining of the SLNs. Because most patients with DCIS lesions detected by routine H&E stains do not have regional lymph node metastases, these patients can safely avoid the complications associated with a complete axillary lymph node dissection and systemic chemotherapy. However, DCIS patients with occult micrometastases of the regional lymphatic basin can be staged with higher accuracy and treated in a more selective fashion.

The relevance of occult axillary micrometastasis in ductal carcinoma in situ

“…It is a useful parameter for statistical measure that has aided in the design and implementation of various therapeutic study protocols throughout the years and with apparent clinical benefit. 2 However, the biologic potential of a tumor may also depend on other factors, including primary tumor size/volume, histologic and nuclear grades, lymphovascular invasion, and tumor necrosis/fibrosis. 4 All these features may in some way work to enhance partially or prominently the ability of a neoplasm to survive and proliferate at a secondary site.…”

“…Lymph node tumor involvement, which has always been believed to be of great clinical prognostic importance, has taken on added significance with the advent of sentinel lymph node evaluation. 2 Sentinel lymph node evaluation represents a potential milestone that may obviate the need for full axillary dissections in a significant proportion of patients, especially patients with early and/or minimal breast carcinoma. The potential of this procedure to decrease dramatically patient morbidity and effect appreciable cost savings, as well as enhance patient care, is an attractive incentive to the medical community.…”

“…12 In addition, the decrease in morbidity associated with lymph node evaluation is another reason to proceed in this direction. 2 The distinction between micrometastasis and macrometastasis was defined many years ago as a measurable focus of tumor greater or less than 2 mm in maximum dimension. 7,8 This measurement criterion had been found to have prognostic relevance and has been used as a standard part of many reports for years.…”

“…2 However, even with early detection, there still exists a percentage of treatment failures, either in the form of disease recurrence or metastasis. Failure rates of 15-20% for early disease is well documented in the literature.…”

“…11,12 These metastases have been attributed to various factors, including the failure to identify a small invasive component and the histologically subtle loss of a restricting basement membrane, a phenomenon usually associated with high-grade intraductal lesions. 2 These postulates are acceptable in light of the fact that DCIS represents a heterogeneous group of neoplastic and, in some cases, preneoplastic processes in various stages of dedifferentiation. 13,14 The advent of sentinel lymph node evaluation is a milestone that is revolutionizing treatment of the axilla in breast disease.…”