Table 2.
Pathologic and molecular characteristics, comparing primary tumors in EXL (external quadrants and axillary tail), INL (internal quadrants), and NAL (nipple and areola) locations.
| Pathologic characteristics | EXL | INL | NAL | p value |
|---|---|---|---|---|
| N = 160 | N = 58 | N = 17 | ||
| Histologic type (%) | 0.418¥ | |||
| No special type (NST) | 73.8% (n = 118) | 81.0% (n = 47) | 52.9% (n = 9) | |
| Invasive lobular | 9.4% (n = 15) | 6.9% (n = 4) | 29.4% (n = 5) | |
| Invasive tubular | 0.01% (n = 2) | 0.0% (n = 0) | 0.0% (n = 0) | |
| Ductal in situ | 8.8% (n = 14) | 8.6% (n = 5) | 11.8% (n = 2) | |
|
| ||||
| Tumor diameter, mm | 0.641Ω | |||
| Minimum | 2.0 | 5.0 | 2.0 | |
| Maximum | 60.0 | 62.0 | 50.0 | |
| Mean ± SD | 17.4 ± 10.2 | 15.2 ± 10.6 | 14.7 ± 10.2 | |
|
| ||||
| LVI (%) | 5.6% (n = 9) | 8.6% (n = 5) | 5.9% (n = 1) | 0.817¥ |
|
| ||||
| Grade | 0.048¥ | |||
| Grade 1 (%) | 51.9% (n = 83) | 46.6% (n = 27) | 29.4% (n = 4) | |
| Grade 2 (%) | 44.4% (n = 71) | 41.4% (n = 24) | 52.9% (n = 9) | |
| Grade 3 (%) | 3.7% (n = 6) | 12.0% (n = 7) | 17.6% (n = 3) | |
|
| ||||
| Ki67, % | 0.798Ω | |||
| Minimum | <10 | 1 | <10 | |
| Maximum | 90 | 40 | 30 | |
| Mean ± SD | 13 ± 12.1 | 14 ± 11.1 | 15 ± 8.6 | |
|
| ||||
| Intrinsic molecular subtype (%) | 0.531¥ | |||
| Luminal A | 56.3% (n = 90) | 58.6% (n = 34) | 52.9% (n = 9) | |
| Luminal B | 20.0% (n = 32) | 17.2% (n = 10) | 23.5% (n = 4) | |
| Luminal B/(HER2)+ | 11.9% (n = 19) | 10.3% (n = 6) | 5.9% (n = 1) | |
| HER2-enriched | 0.0% (n = 0) | 1.7% (n = 1) | 5.9% (n = 1) | |
| Triple negative | 1.9% (n = 3) | 3.4% (n = 2) | 0.0% (n = 0) | |
Note: ¥: chi-square test, Ω: one-way ANOVA. Bold value denotes that the p value was statistically significant.
Abbreviations: HER2, human epidermal growth factor receptor-2; LVI, lymphovascular invasion; SD, standard deviation.