Table 2.

Tumor characteristics by breast cancer subtype

Luminal ALuminal BBasal-likeHER2-enrichedTotal
(N = 615)(N = 42)(N = 210)(N = 67)(N = 934)
N (%)N (%)N (%)N (%)N (%)
Grade
 198 (15.9)0 (0)8 (3.8)0 (0)106 (11.3)
 2460 (74.8)23 (54.8)83 (39.5)28 (41.8)594 (63.6)
 354 (8.8)19 (45.2)118 (56.2)38 (56.7)229 (24.5)
 Unknown3 (0.5)0 (0)1 (0.5)1 (1.5)5 (0.5)
  P < 0.0001
TNM stage
 1340 (55.3)15 (35.7)82 (39.0)19 (28.4)456 (48.8)
 2216 (35.1)21 (50.0)107 (51.0)37 (55.2)381 (40.8)
 328 (4.6)3 (7.1)13 (6.2)7 (10.4)51 (5.5)
 423 (3.7)1 (2.4)7 (3.3)4 (6.0)35 (3.7)
 Unknown8 (1.3)2 (4.8)1 (0.5)0 (0)11 (1.2)
  P < 0.0001
Lymph nodes
 Negative374 (60.8)20 (47.6)128 (61.0)28 (41.8)550 (58.9)
 Positive207 (33.7)18 (42.9)71 (33.8)33 (49.3)329 (35.2)
 Unknown34 (5.5)4 (9.5)11 (5.2)6 (9.0)55 (5.9)
  P = 0.019
Surgical margins
 No residual tumor570 (92.7)39 (92.9)193 (91.9)63 (94.0)865 (92.6)
 Microscopic residual tumor32 (5.2)1 (2.4)10 (4.8)4 (6.0)47 (5.0)
 Margins not evaluable3 (0.5)1 (2.4)3 (1.4)0 (0)7 (0.7)
 No primary site surgery4 (0.7)1 (2.4)2 (1.0)0 (0)7 (0.7)
 Unknown6 (1.0)0 (0.0)2 (1.0)0 (0)8 (0.9)
  P = 0.66
Histopathology
 IDC521 (84.7)37 (88.1)192 (91.4)57 (85.1)807 (86.4)
 ILC61 (9.9)2 (4.8)12 (5.7)3 (4.5)78 (8.4)
 Unknown/other33 (5.4)3 (7.1)6 (2.9)7 (10.4)49 (5.2)
  P = 0.056

NOTE: P values based on χ2 test. Unknown excluded in calculation of P value. For variables with categories <5, P values are based on the Fisher exact test.

Abbreviations: IDC, Invasive ductal carcinoma; ILC, Invasive lobular carcinoma.