Table 1.

Characteristics of women in the training and validation data sets

Training dataValidation data
Total number of women5,7295,534
Breast cancer deaths, n (%)994 (17)1,079 (20)
Missing breast cancer deaths, n (%)0 (0)118 (2)
Other deaths, n (%)680 (12)208 (4)
Missing other deaths, n (%)0 (0)118 (2)
Median age at diagnosis (IQR), years58 (17)40 (13)
Median tumor size (IQR), mm19 (13)20 (15)
Missing tumor size, n (%)0 (0)157 (3)
Median number of nodes (IQR)0 (2)0 (2)
Grade, n (%)
 I987 (18)702 (13)
 II2,932 (51)1,918 (35)
 III1,810 (32)2,914 (53)
ER status, n (%)
 Positive4,711 (82)3,879 (70)
 Negative1,018 (18)1,655 (30)
Adjuvant therapy, n (%)
 None735 (13)1,310 (24)
 Chemo909 (16)1,562 (28)
 Hormone2,981 (52)1,020 (18)
 Both1,104 (19)1,642 (30)