Table 1.
Characteristics of NSLN- and NSLN+ cases among SLN+ patients (Bay Area SLN Database).
| Tumor-free NSLN | Tumor-involved NSLN | Univariate P ∫ | Multivariate P ∫∫ | %NSLN+ (NSLN+/SLN+) | TOTAL SLN+ | ||||||||
| Patient and Tumor Characteristics | Number of Pts (n = 184) | % | Mean | SEM* | Number of Pts (n = 101) | % | Mean | SEM* | Number of Pts (n = 285) | % | |||
| Patient Age (years) | 55.8 | 0.89 | 53 | 1.14 | 0.084 | NA | |||||||
| Tumor Type | |||||||||||||
| Infiltrating Ductal Carcinoma | 159 | 86 | 87 | 86 | 0.781 | NA | 35% | 246 | 86.3 | ||||
| Invasive Lobular Carcinoma | 18 | 10 | 9 | 9 | 33% | 27 | 9.5 | ||||||
| Mixed Carcinoma | 6 | 3 | 5 | 5 | 45% | 11 | 3.9 | ||||||
| Tubular Carcinoma | 1 | 1 | 0 | 0 | 0% | 1 | 0.4 | ||||||
| Tumor size (cm) | 2.11 | 0.1 | 2.97 | 0.18 | <0.001 | <0.001 | |||||||
| Tumor size (AJCC) | 0.001 | 0.045 | |||||||||||
| T1 | 117 | 64 | 39 | 39 | 25% | 156 | 54.7 | ||||||
| T1a (mic) | 1 | 1 | 0 | 0 | 0% | 1 | 0.4 | ||||||
| T1a | 6 | 3 | 2 | 2 | 25% | 8 | 2.8 | ||||||
| T1b | 19 | 10 | 3 | 3 | 14% | 22 | 7.7 | ||||||
| T1c | 91 | 49 | 34 | 34 | 27% | 125 | 43.9 | ||||||
| T2 | 59 | 32 | 50 | 50 | 46% | 109 | 38.2 | ||||||
| T3 | 8 | 4 | 12 | 12 | 60% | 20 | 7.0 | ||||||
| Tumor grade† | 0.001 | 0.736 | |||||||||||
| G1: Nottingham combined histologic score 3–5 | 68 | 37 | 23 | 23 | 25% | 91 | 31.9 | ||||||
| G2: Nottingham combined histologic score 6–7 | 81 | 44 | 39 | 39 | 33% | 120 | 42.1 | ||||||
| G3: Nottingham combined histologic score 8–9 | 35 | 19 | 39 | 39 | 53% | 74 | 26.0 | ||||||
| ER status | 0.004 | 0.079 | |||||||||||
| Negative | 17 | 9 | 21 | 21 | 55% | 38 | 13.3 | ||||||
| Positive | 134 | 73 | 60 | 59 | 31% | 194 | 68.1 | ||||||
| Unknown | 33 | 18 | 20 | 20 | 38% | 53 | 18.6 | ||||||
| PR status | 0.015 | 0.869 | |||||||||||
| Negative | 35 | 19 | 31 | 31 | 47% | 66 | 23.2 | ||||||
| Positive | 116 | 63 | 50 | 50 | 30% | 166 | 58.2 | ||||||
| Unknown | 33 | 18 | 20 | 20 | 38% | 53 | 18.6 | ||||||
| HER2/neu expression | 0.256 | NA | |||||||||||
| Not overexpressed, 0+ or 1+ | 81 | 44 | 38 | 38 | 32% | 119 | 41.8 | ||||||
| Equivocal, weak overexpression, 2+ | 2 | 1 | 2 | 2 | 50% | 4 | 1.4 | ||||||
| Overexpressed, 3+ | 29 | 16 | 23 | 23 | 44% | 52 | 18.2 | ||||||
| Unknown | 72 | 39 | 38 | 38 | 35% | 110 | 38.6 | ||||||
| Angiolymphatic invasion | <0.001 | <0.001 | |||||||||||
| None | 95 | 52 | 23 | 23 | 19% | 118 | 41.4 | ||||||
| Present | 25 | 14 | 70 | 69 | 74% | 95 | 33.3 | ||||||
| Unknown | 64 | 35 | 8 | 8 | 11% | 72 | 25.3 | ||||||
| Sentinel Lymph Node Characteristics | |||||||||||||
| No. SLNs Removed | 1.96 | 0.07 | 1.87 | 0.09 | 0.511 | NA | |||||||
| = 1 | 71 | 39 | 42 | 42 | 0.806 | 37% | 113 | 39.6 | |||||
| = 2 | 67 | 36 | 37 | 37 | 36% | 104 | 36.5 | ||||||
| >2 | 46 | 25 | 22 | 22 | 32% | 68 | 23.9 | ||||||
| No. SLNs Tumor-involved | 1.33 | 0.05 | 1.39 | 0.07 | 0.426 | NA | |||||||
| = 1 | 137 | 73 | 71 | 70 | 0.679 | 34% | 208 | 73.0 | |||||
| = 2 | 38 | 21 | 23 | 23 | 38% | 61 | 21.4 | ||||||
| >2 | 9 | 6 | 7 | 7 | 44% | 16 | 5.6 | ||||||
| Size of SLN metastases§ | <0.001 | <0.001 | |||||||||||
| Isolated tumor cells or clusters ≤ 0.2 mm | 61 | 33 | 3 | 3 | 4.7% | 64 | 22.5 | ||||||
| Micrometastases, >0.2 mm to 2 mm | 117 | 64 | 83 | 82 | 42% | 200 | 70.2 | ||||||
| Macrometastases, >2 mm | 6 | 3 | 15 | 15 | 71% | 21 | 7.4 | ||||||
| Sentinel lymph node metastases identification | <0.001 | NA | |||||||||||
| Hematoxylin and eosin staining | 122 | 61 | 98 | 97 | 45% | 220 | 77.2 | ||||||
| Immunohistochemistry | 62 | 34 | 3 | 3 | 4.6% | 65 | 22.8 | ||||||
∫ Univariate analyses calculated by χ 2 test and Wilcoxon rank sum test.
∫∫ Multivariate analyses calculated by logistic regression of significant factors by univariate analysis.
*SEM, standard error of the mean.
†Determined according to modified Scarff-Bloom-Richardson grading system.
§Determined according to AJCC criteria, 6th ed.
NA, variable not included in multivariate analysis (not an independent factor or not significant in univariate analysis)