Patient ID
x1: Age, years
x2: Menopausal status
x3: Tumour size, mm
x4: Grade
x4a: x4>=2
x4b: x4==3
x5: Number of nodes involved
x5e: exp(-.12*x5)
x6: Number of progesterone receptor
x7: Number of estrogen receptors
x8: Hormone therapy
t: Time to recurrence, days
d: Recurrence/censoring indicator