Fig. 6
![Fig. 6](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12885-016-2417-8/MediaObjects/12885_2016_2417_Fig6_HTML.gif)
Calibration curves for internal validation of nomograms predicting 5-year overall survival. a TNM base model; (b) model combining TNM parameters with categorically coded tumor length; (c) model combining TNM parameters with continuously coded tumor length. The x axis nomogram-predicted probability of overall survival, and the y axis is actual survival. The diagonal line is the reference line indicating perfect calibration. The solid line indicates performance of the current nomogram