The dataset contains cases from a study that was conducted between 1958 and 1970 at the University of Chicago's Billings Hospital on the survival of patients who had undergone surgery for breast cancer.
data(survival)
A data frame with 306 rows and 3 variables:
Age of patient at time of operation (numerical)
Patient's year of operation (year - 1900, numerical)
Number of positive axillary nodes detected (numerical)
(class attribute) -- 1 = the patient survived 5 years or longer -- 2 = the patient died within 5 year