The gbsg data set contains patient records from a 1984-1989 trial 
conducted by the German Breast Cancer Study Group (GBSG) of 720 patients
with node positive breast cancer; it retains the 686 patients with 
complete data for the prognostic variables.
gbsg
data(cancer, package="survival")A data set with 686 observations and 11 variables.
pidpatient identifier
ageage, years
menomenopausal status (0= premenopausal, 1= postmenopausal)
sizetumor size, mm
gradetumor grade
nodesnumber of positive lymph nodes
pgrprogesterone receptors (fmol/l)
erestrogen receptors (fmol/l)
hormonhormonal therapy, 0= no, 1= yes
rfstimerecurrence free survival time; days to first of reccurence, death or last follow-up
status0= alive without recurrence, 1= recurrence or death
These data sets are used in the paper by Royston and Altman. The Rotterdam data is used to create a fitted model, and the GBSG data for validation of the model. The paper gives references for the data source.
Patrick Royston and Douglas Altman, External validation of a Cox prognostic model: principles and methods. BMC Medical Research Methodology 2013, 13:33
rotterdam