Table 1.

Study population characteristics

NHS/CGEMSSEARCH
Total no. of subjects1,1454,335
Total time at risk, y7,71128,148*
Median time at risk, y6.00 (0.001-15.00)6.51 (0.036-9.81)
No. of breast cancer deaths93587
Annual mortality rate0.012 (0.010-0.014)0.021 (0.019-0.023)
5-y survival rate0.94 (0.944-0.969)0.89 (0.883-0.905)
Median age at diagnosis, y66 (44-83)51 (23-69)
Histopathologic grade, n (%)
    Well differentiated209 (18.25)858 (19.79)
    Moderately differentiated389 (33.97)1,652 (38.11)
    Poorly differentiated243 (21.22)989 (22.81)
    Unknown304 (26.55)836 (19.28)
Clinical stage, n (%)
    I725 (63.32)2,133 (49.20)
    II300 (26.20)1,924 (44.38)
    III49 (4.28)142 (3.28)
    IV0 (0.00)44 (1.01)
    Unknown71 (6.20)92 (2.12)
Estrogen receptor status, n (%)
    Positive807 (70.48)2,440 (56.29)
    Negative181 (15.81)639 (14.74)
    Unknown157 (13.71)1,256 (28.97)
  • *Follow-up censored at 10 y, analysis allowing for left-truncated data.

  • Range of variable.

  • 95% confidence interval.