Supplementary Table 3: Clinical and pathologic data for the 696 patients with invasive breast cancer having at least one metastatic sentinel lymph node (SN) and comparison between the group of 518 patients having axillary lymph node dissection (ALND) and the group of 170 patients who did not have ALND (8 patient were lost to follow-up).

positive SN (n=696) / ALND (n=518) / no ALND (170) / p-value
No / % / No / % / No / %
Age, years
mean (range) / 59.6 (25-98) / 59.2 (26-98) / 60.9 (31-92) / 0.1
Palpable mass / 448 / 64.6 / 345 / 66.7 / 99 / 58.6 / 0.07
Invasive tumor size at final histology, mm
mean (range) / 18.9 (1-90) / 19.7 (1-70) / 16.3 (3-90) / <0.0001
pT1 / 465 / 66.9 / 329 / 63.6 / 132 / 77.6 / 0.003
pT2 / 221 / 31.8 / 180 / 34.8 / 37 / 21.8
pT3 / 9 / 1.3 / 8 / 1.6 / 1 / 0.6
not determined / 1 / 1 / 0
Histology / 0.01
invasive ductal carcinoma / 576 / 82.7 / 416 / 80.3 / 151 / 90
invasive lobular carcinoma / 84 / 12.1 / 71 / 13.7 / 12 / 7.1
other / 36 / 5.2 / 31 / 6 / 7 / 2.9
not determined
Tumor grade / 0.03
well differentiated, grade 1 / 142 / 20.5 / 96 / 18.7 / 46 / 27.1
moderately differentiated, grade 2 / 371 / 52.7 / 275 / 53.6 / 90 / 52.9
poorly differentiated, grade 3 / 175 / 25.8 / 142 / 27.7 / 34 / 20
not determined / 5 / 5
Lymphovascular space involvement / 0.04
No / 393 / 62.7 / 281 / 60.4 / 108 / 70.1
Yes / 234 / 37.3 / 184 / 39.6 / 46 / 29.9
not determined / 69 / 53 / 16
Estrogen/progesterone receptor status / 0.5
positive / 619 / 89.5 / 458 / 88.9 / 155 / 91.2
negative / 73 / 10.5 / 57 / 11.1 / 15 / 8.8
not determined / 4 / 3
Her-2/neu status / 0.3
overexpressed/amplified / 69 / 10.3 / 55 / 11 / 13 / 8
negative / 600 / 89.7 / 445 / 89 / 150 / 92
not determined / 27 / 18 / 7
Mean No of SN per patient (range) / 2.35 (1-12) / 2.24 (1-12) / 2.64 (1-11) / 0.008
Mean No of positive SN per patient (range) / 1.29 (1-7) / 1.35 (1-7) / 1.10 (1-5) / <0.0001
No of patients with :
macrometastases / 368 / 52.9 / 334 / 64.6 / 28 / 16.5 / <0.0001
H&E /IHC / 282 / 84 / 253 / 70 / 15 / 13
micrometastases / 231 / 33.2 / 144 / 27.9 / 85 / 50
H&E /IHC / 117 / 114 / 86 / 61 / 33 / 52
ITC / 86 / 12.4 / 33 / 6.4 / 53 / 31.2
H&E /IHC / 21 / 65 / 10 / 23 / 11 / 42
RT-PCR / 10 / 1.4 / 6 / 1.2 / 4 / 2.3
not determined / 3 / 1
Histologic detection of SN metastasis
Per operative detection: frozen section / 170 / 29.7 / 167 / 37.7 / 3 / 6.5 / <0.0001
imprint cytology / 26 / 22 / 4
RT-PCR / 10 / 6 / 4
routine H&E / 192 / 27.7 / 145 / 28 / 42 / 24.7
serial H&E / 33 / 4.7 / 23 / 4.5 / 10 / 5.9
IHC / 263 / 37.9 / 154 / 29.8 / 107 / 62.9
not determined / 2 / 1
Ratio of metastatic SN to total SN
Mean ratio (range) / 0.68 (0.08-1) / 0.71 (0.08-1) / 0.58 (0.09-1) / <0.0001
1 / 301 / 43.2 / 242 / 46.7 / 56 / 32.9
0.5-1 / 229 / 32.9 / 179 / 34.6 / 47 / 27.6
<0.5 / 166 / 23.9 / 97 / 18.7 / 67 / 39.4
ALND
Mean No of non-SN per patient (range) / 10.3 (1-39)
No of patient with positive non-SN / 167 / 32.2
Mean No of non-SN positive per patient (range) / 3.6 (1-27)
Abbreviations: SN: sentinel lymph node; ALND: axillary lymph node dissection; H&E: hematoxylin and eosin; IHC: immunohistochemistry; ITC: isolated tumors cells; RT-PCR: Reverse transcription polymerase chain reaction; non-SN: nonsentinel lymph node.

Comment: Subgroup of patients with metastatic SN who did not have ALND

Among the 696 patients having at least one metastatic SN, 170 patients (24.4%) did not have ALND. false reassurance rate was over 10%. Moreover, only a minority of patients were eligible for omission of ALND by the use of models

Clinical and pathologic data for the 696 patients and a comparison between the group of patients having ALND and the group of patients who did not have ALND are listed in Table 3. In multivariate analysis, factors associated with achieving an ALND were the invasive tumor size at final histology (mm) with an OR of 1.03 (95% CI: 1-1.06, p=0.03), the ratio of metastatic SN to total SN with an OR of 2.84 (95% CI: 1.38-5.84, p=0.004), the type of SN metastases (macrometastases=reference versus micrometastases versus ITC) with an OR of 0.18 (95% CI: 0.11-0.3, p<0.0001) and 0.07 (95% CI: 0.03-0.14, p<0.0001) for micrometastases and ITC, respectively, as well as the type of histological detection of SN metastasis with an OR of 0.47 (95% CI: 0.24-0.92, p=0.01) for IHC versus H&E.