Table 1.

The missing values of predictor variables

Variables	Frequency	Percentage
Race	85	0.5
Marital status	674	3.8
Primary site code	4196	23.8
Histology	0	0
Behavior	0	0
Grade	3033	17.2
Extension of tumor	384	2.2
Lymph node involvement	647	3.7
Radiation	131	0.7
Stage	388	2.2
Site specific surgery code	68	0.4
ERStatus	0	0
PRStatus	0	0
Age	0	0
Tumor size	2930	17.9
Number of positive nodes	102	0.6
Number of nodes	96	0.5
Number of primaries	0	0