Axillary Lymph Node Status in Early-Stage Breast Cancer Patients with Sentinel Node Micrometastases (0.2-2 mm)

Abstract

Background: Omission of axillary lymph node dissection (ALND) is increasingly becoming the new standard of care for patients with sentinel lymph node micrometastases (SNMMs). However, a formidable proportion of patients is afflicted with non-sentinel node (NSN) macrometastatic tumor burden. Methods: Over 1 decade 5,000 patients underwent sentinel node biopsies (SNB) at 2 certified breast cancer centers in Austria. All available cases of SNMM during this time period were reviewed. Clinical, tumor and lymph node parameters were analyzed using univariate and multivariate analysis to retrieve predictors for further NSN involvement. Results: We identified 216 patients with SNMMs, of whom 181 subsequently underwent ALND. Of the latter patients, 16% (n = 29/181) presented with NSN axillary metastases. ALND revealed NSN macrometastases in 10.5% (n = 19/181) of all the investigated patients, and 66% of the NSN-positive patients (n = 19/29). In 28% (n = 8/29) of the NSN-positive patients, more than 1 macrometastasis was detected. The number of removed sentinel nodes was found to be a significant predictor (p = 0.007) for NSN involvement. Conclusion: In this retrospective investigation of breast cancer patients with SNMMs, a substantial proportion exhibited involvement of NSNs. Macrometastases accounted for the largest fraction of NSN tumor burden. Refraining from ALND in the face of SNMMs may entail substantial micro- and macrometastatic tumor burden in the remaining axillary lymph node basin.

Prognostic Significance of Further Axillary Dissection in Breast Cancer Patients with Micrometastases & the Number of Micrometastases: a SEER Population-Based Analysis

“…It is noted that several studies have reported the specific situation of SLN examination and the number of micrometastases, and some studies included ITC in their analysis. In this study, 54.1% of the patients had one to two SLNs removed, which was similar to previous research [ 26 , 30 , 36 ]. Moreover, the median and range of SLNs in our study were also consistent with previous research [ 17 , 24 , 26 , 27 , 29 , 30 , 36 ].…”

“…In this study, 54.1% of the patients had one to two SLNs removed, which was similar to previous research [ 26 , 30 , 36 ]. Moreover, the median and range of SLNs in our study were also consistent with previous research [ 17 , 24 , 26 , 27 , 29 , 30 , 36 ]. However, two studies showed both a higher median number and wider range [ 37 , 38 ].…”

“…However, two studies showed both a higher median number and wider range [ 37 , 38 ]. Regarding the micrometastatic SLNs, most studies have indicated an extremely high percentage of one and two positive SLNs [ 17 , 24 , 30 , 39 ], and several studies selected one as a cut-off point [ 36 , 37 , 40 ] without demonstrating additional details concerning the low quantity; other studies have shown no more than two invaded [ 25 , 27 , 29 ]. The relative small probability to discover three micrometastases in SLNs was caused by the low number of SLN examinations.…”

“…However, we attempted to obtain an unbiased comparison using propensity score matching. Moreover, if further ALNDs are administered in patients with one to two micrometastatic SLNs, there is a low likelihood (7.1–18%) of identifying one or more non-SLN metastases [ 4 , 17 , 23 , 25–27 , 29 , 30 , 36 , 38 , 40 ], with several studies combining micrometastases and ITCs as a category. Thus, we could not consider these missing patients, who originally should have been in our ALND group.…”