Table 4 Cox proportional hazard model for selected second cancer entities adjusted for age, T-, N- and M-category and treatment as independent covariates

 Colon cancer

0.0035

  RPE only

1

  RT only

1.326

0.970

1.813

  RT after RPE

1.903

1.269

2.853

 Rectal cancer

0.0077

  RPE only

1

  RT only

1.751

1.179

2.601

  RT after RPE

0.638

0.278

1.465

 Lung cancer

0.0011

  RPE only

1

  RT only

1.733

1.293

2.324

  RT after RPE

1.017

0.598

1.730

 Bladder cancer

  RPE only

1

<0.0001

  RT only

2.098

1.585

2.778

  RT after RPE

1.601

1.001

2.561

 Non-melanoma skin cancer

  RPE only

1

0.0020

  RT only

1.658

1.246

2.205

  RT after RPE

1.305

0.802

2.124