GBSG2 {TH.data}

German Breast Cancer Study Group 2

Description

A data frame containing the observations from the GBSG2 study.

Usage

data("GBSG2")

Format

This data frame contains the observations of 686 women:

horTh

hormonal therapy, a factor at two levels no and yes.

age

of the patients in years.

menostat

menopausal status, a factor at two levels pre (premenopausal) and post (postmenopausal).

tsize

tumor size (in mm).

tgrade

tumor grade, a ordered factor at levels I < II < III.

pnodes

number of positive nodes.

progrec

progesterone receptor (in fmol).

estrec

estrogen receptor (in fmol).

time

recurrence free survival time (in days).

cens

censoring indicator (0- censored, 1- event).

Source

W. Sauerbrei and P. Royston (1999). Building multivariable prognostic and diagnostic models: transformation of the predictors by using fractional polynomials. Journal of the Royal Statistics Society Series A, Volume 162(1), 71–94.

References

M. Schumacher, G. Basert, H. Bojar, K. Huebner, M. Olschewski, W. Sauerbrei, C. Schmoor, C. Beyerle, R.L.A. Neumann and H.F. Rauschecker for the German Breast Cancer Study Group (1994), Randomized 2\times2 trial evaluating hormonal treatment and the duration of chemotherapy in node-positive breast cancer patients. Journal of Clinical Oncology, 12, 2086–2093.

Examples

data(GBSG2)

thsum <- function(x) {
  ret <- c(median(x), quantile(x, 0.25), quantile(x,0.75))
  names(ret)[1] <- "Median"
  ret
}

t(apply(GBSG2[,c("age", "tsize", "pnodes", 
                 "progrec", "estrec")], 2, thsum))

table(GBSG2$menostat)
table(GBSG2$tgrade)
table(GBSG2$horTh)