Table 2.

Tumor characteristics by histologic subtype

Ductal casesLobular casesMixed casesχ2P*
n (%)n (%)n (%)
Age at most recent mammogram, y
    40-493,019 (20)261 (16)324 (20)<0.01
    50-594,322 (29)428 (27)470 (29)
    60-693,675 (25)403 (25)405 (25)
    70-843,802 (26)510 (32)402 (25)
Estrogen receptor status
    Positive9,975 (79)1,321 (95)1,307 (94)<0.01
    Negative2,620 (21)63 (5)86 (6)
    Missing2,223218208
Progesterone receptor status
    Positive8,531 (69)1,106 (82)1,155 (85)<0.01
    Negative3,797 (31)247 (18)208 (15)
    Missing2,490249228
HER2/neu status
    Positive661 (17)30 (7)35 (7)<0.01
    Negative3,299 (83)427 (93)437 (93)
    Missing10,8581,1751,129
Stage at diagnosis
    I8,343 (60)690 (45)782 (51)<0.01
    IIA3,000 (21)368 (24)379 (25)
    IIB1,133 (8)198 (13)149 (10)
    III1,264 (9)232 (15)200 (13)
    IV226 (2)38 (2)28 (2)
    Missing8527663
Grade at diagnosis
    13,317 (24)372 (30)360 (24)<0.01
    25,690 (41)671 (54)771 (52)
    34,593 (33)180 (15)320 (22)
    4259 (2)14 (1)21 (1)
    Missing959365129

Abbreviation: HER2, human epidermal growth factor receptor.

  • * P values presented are from χ2 tests comparing the distribution of characteristics across the three tumor subtypes.