| One SLN identified (n = 104) | Two or more SLNs identified (n = 249) | P-value |
---|---|---|---|
Age (mean ± SD, years) | 56 ± 11 | 56 ± 12 | 0.870 |
Height (mean ± SD, inches) | 64 ± 3 | 64 ± 2 | 0.386 |
Weight (mean ± SD, pounds) | 174 ± 45 | 165 ± 35 | 0.041 |
BMI (mean ± SD, kg/m2) | 29.5 ± 6.9 | 28.3 ± 6.0 | 0.101 |
Breast size | Â | Â | 0.053 |
   Small | 6 (6%) | 25 (10%) |  |
   Medium | 31 (30%) | 101 (41%) |  |
   Large | 41 (39%) | 83 (33%) |  |
   Not available | 26 (25%) | 40 (16%) |  |
Palpable tumor | 53 (51%) | 120 (48%) | 0.635 |
Tumor location | Â | Â | 0.259 |
   UOQ | 51 (49%) | 142 (57%) |  |
   LOQ | 21 (20%) | 33(13%) |  |
   UIQ | 20 (19%) | 38 (15%) |  |
   LIQ | 9 (9%) | 21 (8%) |  |
   Central | 3 (3%) | 15 (6%) |  |
Type of diagnostic breast biopsy | Â | Â | 0.301 |
   Core | 79 (76%) | 191 (77%) |  |
   Excisional | 24 (23%) | 58 (23%) |  |
   Fine needle aspiration | 1 (1%) | 0 (0%) |  |
Pathologic T-stage | Â | Â | 0.617 |
   T1 | 68 (65%) | 176 (71%) |  |
   T2 | 34 (33%) | 69(28%) |  |
   T3 | 2 (2%) | 4 (2%) |  |
Histopathology | Â | Â | 0.958 |
   Ductal | 90 (87%) | 216 (87%) |  |
   Lobular | 3 (3%) | 18 (7%) |  |
   Mixed Ductal-Lobular | 3 (3%) | 9 (4%) |  |
   Other | 8 (8%) | 6 (2%) |  |
Histologic grade | Â | Â | 0.032 |
   Well-differentiated | 11 (11%) | 56 (23%) |  |
   Moderately-differentiated | 47 (45%) | 101 (41%) |  |
   Poorly-differentiated | 46 (44%) | 92 (37%) |  |
Estrogen receptor positive | 77 (74%) | 198 (80%) | 0.258 |
Progesterone receptor positive | 63 (61%) | 165 (66%) | 0.308 |
HER-2/neu positive | 27 (26%) | 46 (19%) | 0.136 |
Lymphovascular invasion | 24 (23%) | 48 (19%) | 0.419 |
Route of injection of 99 mTc-sulfur colloid | Â | Â | 0.428 |
   Intradermal | 33 (32%) | 92 (37%) |  |
   Intraparenchymal | 38 (37%) | 74 (30%) |  |
   Subareolar | 33 (32%) | 83 (33%) |  |
Surgery performed at time of SLN biopsy | Â | Â | 0.184 |
   Lumpectomy | 80 (77%) | 169 (68%) |  |
   Mastectomy | 21 (20%) | 74 (30%) |  |
   SLN biopsy alone | 3 (3%) | 6 (2%) |  |
Time from 99 mTc-sulfur colloid injection to SLN biopsy (mean ± SD, minutes) | 290 ± 78 | 287 ± 66 | 0.682 |