Table 1.

Baseline patient characteristics

Patient dataTraining set 1 (N = 33)Training set 2 (N = 19)Training set 3 (N = 35)Validation set 1a (N = 19)Validation set 1b (N = 26)
Gender
 Male24 (72.7%)11 (57.9%)16 (45.7%)12 (63.2%)18 (69.2%)
 Female9 (27.3%)8 (42.1%)19 (54.3%)7 (21.2%)8 (30.8%)
Age
 Mean55.665.063.361.860.2
 Range(22.0–78.1)(47.3–77.9)(37–82)(33.9–84.5)(34–82)
Chemotherapy regimen
 Cetuximab002 (5.7%)00
 Cetuximab + irinotecan24 (72.7%)11 (57.9%)16 (45.7%)00
 Cetuximab + Xeloda1 (3.0%)0000
 Cetuximab + FOLFIRI5 (15.2%)4 (21.1%)4 (11.4%)00
 Cetuximab + FOLFOX2 (6.0%)01 (2.9%)00
 Panitumumab04 (21.1%)8 (22.9%)00
 Panitumumab + XELIRI001 (2.9%)00
 Panitumumab + irinotecan1 (3.0%)03 (8.6%)19 (100%)26 (100%)
Number of treatment lines before anti-EGFR therapy
 Median22322
 Range(1–5)(1–6)(1–6)(1–6)(1–6)
 Complete response2 (6.0%)001 (5.3%)2 (7.7%)
Response according to RECIST criteria
 Partial response10 (30.3%)4 (21.1%)13 (37.1%)7 (36.8%)8 (30.8%)
 Stable disease11 (33.3%)9 (47.4%)10 (28.6%)6 (31.6%)8 (30.8%)
 Progressive disease10 (30.3%)6 (31.6%)12 (34.3%)5 (26.3%)7 (26.9%)