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Recurrence-free survival times, in days, of 686 patients with node-positive breast cancer from the German Breast Cancer Study Group (Collett, 2023, Example 6.5).

Usage

breast_rfs

Format

A data frame with 686 rows and 11 variables:

id

Patient number.

treat

Hormonal treatment: 0 = no tamoxifen, 1 = tamoxifen.

age

Age of the patient in years.

men

Menopausal status: 1 = premenopausal, 2 = postmenopausal.

size

Tumour size in mm.

grade

Tumour grade (1, 2 or 3).

nodes

Number of positive lymph nodes.

prog

Progesterone receptor status (femtomoles).

oest

Oestrogen receptor status (femtomoles).

time

Recurrence-free survival time in days.

status

Event indicator: 1 = relapse or death, 0 = right-censored.

Source

Collett, D. (2023) Modelling Survival Data in Medical Research, 4th ed. Chapman & Hall/CRC, Example 6.5 (Table 6.1). Data from Schumacher et al. (1994) and Sauerbrei and Royston (1999).

Details

The patients had primary, histologically proven, non-metastatic node-positive breast cancer treated with mastectomy; the study compared three with six cycles of chemotherapy and investigated additional hormonal treatment. Recurrence-free survival is the time from entry until a recurrence of the cancer or death, and there are 299 events.

The example introduces flexible parametric (Royston-Parmar) models with a treatment effect and several prognostic variables (Examples 6.5 and 6.6).

Aliases

The data set is available under the aliases d6.5, d6.6; dX.Y is the alias for the data set used in Example X.Y of Collett (2023). See dataset_by_exercise for the complete index.

Examples

# Collett (2023), Chapter 17 style -----------------------------------
# Examples 6.5 and 6.6: log-logistic (proportional odds) model
survival::survreg(
  survival::Surv(time, status) ~ treat + age + men + size + grade +
    nodes + prog + oest,
  data = breast_rfs, dist = "loglogistic"
)
#> Call:
#> survival::survreg(formula = survival::Surv(time, status) ~ treat + 
#>     age + men + size + grade + nodes + prog + oest, data = breast_rfs, 
#>     dist = "loglogistic")
#> 
#> Coefficients:
#>   (Intercept)         treat           age           men          size 
#>  7.8239614739  0.3211627402  0.0130429842 -0.2890810649 -0.0066881339 
#>         grade         nodes          prog          oest 
#> -0.2300284356 -0.0516203143  0.0016303009 -0.0000607376 
#> 
#> Scale= 0.5701717 
#> 
#> Loglik(model)= -2567   Loglik(intercept only)= -2627.9
#> 	Chisq= 121.9 on 8 degrees of freedom, p= <2e-16 
#> n= 686 

# Modern tools --------------------------------------------------------
if (requireNamespace("flexsurv", quietly = TRUE)) {
  flexsurv::flexsurvspline(
    survival::Surv(time, status) ~ treat + age + men + size + grade +
      nodes + prog + oest,
    data = breast_rfs, k = 1
  )
}
#> Call:
#> flexsurv::flexsurvspline(formula = survival::Surv(time, status) ~ 
#>     treat + age + men + size + grade + nodes + prog + oest, data = breast_rfs, 
#>     k = 1)
#> 
#> Estimates: 
#>         data mean  est        L95%       U95%       se         exp(est) 
#> gamma0         NA  -1.92e+01  -2.24e+01  -1.60e+01   1.65e+00         NA
#> gamma1         NA   2.76e+00   2.23e+00   3.28e+00   2.68e-01         NA
#> gamma2         NA   2.15e-01   1.40e-01   2.89e-01   3.79e-02         NA
#> treat    3.59e-01  -3.33e-01  -5.86e-01  -8.01e-02   1.29e-01   7.17e-01
#> age      5.31e+01  -8.96e-03  -2.70e-02   9.06e-03   9.20e-03   9.91e-01
#> men      1.58e+00   2.62e-01  -9.64e-02   6.21e-01   1.83e-01   1.30e+00
#> size     2.93e+01   7.55e-03  -9.43e-05   1.52e-02   3.90e-03   1.01e+00
#> grade    2.12e+00   2.78e-01   7.02e-02   4.85e-01   1.06e-01   1.32e+00
#> nodes    5.01e+00   5.04e-02   3.60e-02   6.49e-02   7.37e-03   1.05e+00
#> prog     1.10e+02  -2.23e-03  -2.56e-03  -1.90e-03   1.67e-04   9.98e-01
#> oest     9.63e+01   1.68e-04  -1.60e-04   4.95e-04   1.67e-04   1.00e+00
#>         L95%       U95%     
#> gamma0         NA         NA
#> gamma1         NA         NA
#> gamma2         NA         NA
#> treat    5.57e-01   9.23e-01
#> age      9.73e-01   1.01e+00
#> men      9.08e-01   1.86e+00
#> size     1.00e+00   1.02e+00
#> grade    1.07e+00   1.62e+00
#> nodes    1.04e+00   1.07e+00
#> prog     9.97e-01   9.98e-01
#> oest     1.00e+00   1.00e+00
#> 
#> N = 686,  Events: 299,  Censored: 387
#> Total time at risk: 771400
#> Log-likelihood = -2562.974, df = 11
#> AIC = 5147.949
#>