Issues Related to Sentinel Lymph Node Assessment in the Management of Breast Cancer—What Are Relevant in Pathology Reports?

Table 2

Important studies on micrometastatic nodes in breast cancer.

Author	Study	Median FU	Patient number	Conclusion
Bulte et al. [18]	7 hospitals in Netherlands	3.8 years	503 pN0; 38 pNmi	Local relapse—5(1.0%) versus 1(2.6%); Regional relapse—0% versus 0%; Distant relapse—17(3.4%) versus 3(7.9%); Combined locoregional relapse—1(0.2%) versus 0%; Combined regional and distant relapse—3(0.6%) versus 0% (n.s., see text for details)
Hainsworth et al. [19]	St Vincent's Hospital, Australia	6.6 years	31/343 occult node metastases found on IHC, plus 10 found on H&E	Among the 31 patients, presence of occult metastases in 2 or more nodes was associated with decreased DFS and OS (𝑃<.05)
Truong et al. [20]	Surveillance Epidemiology and End Results database	7.3 years	62,551 pT1–2pN0-: 57,980 pN0,; 1818 pNmi,; 2753 pNmac >2 mm but <2 cm	10-year BCSS (82.3% versus 91.9%) and OS (68.1% versus 75.7%) in pNmi compared to pN0.; (s.s.)
Colleoni et al. [29]	Italian medical oncology department	4.2 years	1959 pT1-3, pN0, pN1mi or pN0i+), or pN1a (single positive node) and M0	pN1mi/pN0i+ versus pN0 disease: HR = 1.58; 95% CI, 1.01 to 2.47; 𝑃=.047 for DFS; HR = 1.94; 95% CI, 1.04 to 3.64; 𝑃=.037 for distant metastases.
de Boer et al. [21]	Dutch cohort study of all centers in Netherlands (MIRROR study)	5.1 years	(a) 856 Nmi/ITC without adjuvant therapy,; (b) 995 Nmi/ITC with adjuvant therapy,; (c) 856 node-negative	Disease events: (a) for Nmi: HR 1.56 (95% CI:1.15-2.13; for ITC:HR 1.50 (95% CI:1.15-1.94); (b) HR 0.57 (95% CI:0.45-0.73)
Houvenaeghel et al. [33]	A French center	—	SN involvement in 388 times (55.4%) by H&E, 312 times by IHC	May omit additional ALND for pT1a and pT1b tumors, and pT1a-c tumors corresponding to tubular, colloidal or medullary cancers

ALND: axilllary lymph node dissection; DFS: disease-free survival; FU: followup; n.s.: statistically nonsignificant; OS: overall survival; SNB: sentinel node biopsy; s.s.: statistically nonsignificant.