Table 1.

Characteristics of triple-negative versus other breast cancers

VariableOther (N = 1,421), n (%)Triple negative (N = 180), n (%)P*
Mean age at diagnosis (y)57.753<0.0001
Mean follow-up (y)8.97.90.004
Lymph node status
    Positive510 (45.6)87 (54.4)
    Negative609 (54.4)70 (44.6)0.02
    Missing/not tested97/2057/16
Mean tumor size (cm)2.13.0<0.0001
Tumor size (cm)
    T1 (<2)880 (62.7)65 (36.5)
    T2 (≥2 to ≤5)461 (32.8)99 (55.6)
    T3 (>5)64 (4.6)14 (7.9)<0.0001
    Missing162
Tumor grade
    I237 (19.9)15 (9.8)
    II616 (51.8)37 (24.2)
    III336 (28.3)101 (66.0)<0.0001
    Missing
Lymphovascular invasion
    Present419 (32.3)65 (39.6)
    Absent878 (67.7)99 (60.4)0.06
    Missing1240
ER levels
    Positive1167 (86.6)0 (0)NA
    Negative180 (13.4)180 (100)
    Missing or borderline74
PR levels
    Positive1,000 (75.2)0 (0)NA
    Negative350 (24.8)180 (180)
    Missing or borderline91
HER2 status
    Positive163 (16.4)0 (0)NA
    Negative831 (83.6)180 (180)
    Not tested427
Chemotherapy treatment
    Yes357 (25.5)86 (48.6)
    No1,040 (74.5)91 (51.4)<0.0001
    Missing20
Tamoxifen treatment
    Yes756 (54.2)64 (36.2)
    No640 (44.8)113 (63.8)<0.0001
    Missing253
  • Abbreviation: NA, not applicable.

  • * P values were calculated with the use of the χ2 test.