Table 4 Univariate analysis of predictors for pCR in the training and validation cohorts

No. of patients

11

60

10

65

Age (mean, y ± SD)

57 ± 12

54 ± 13

55 ± 13

55 ± 12

0.910

Gender

0.497

 Male

8 (73%)

39 (65%)

6 (60%)

28 (43%)

 Female

3 (27%)

21 (35%)

4 (40%)

37 (57%)

Pretreatment T stage

0.546

 T₂

0

0

1 (10%)

5 (8%)

 T₃

10 (9%)

42 (70%)

9 (90%)

53 (81%)

 T₄

1 (91%)

18 (30%)

0

7 (11%)

Pretreatment N stage

0.121

 N₀

2 (18%)

10 (17%)

4 (40%)

17 (26%)

 N₁

7 (64%)

23 (38%)

6 (60%)

28 (43%)

 N₂

2 (18%)

27 (45%)

0

20 (31%)

Tumor differentiation

0.707

 Well/Moderately

8 (73%)

26 (43%)

7 (70%)

49 (75%)

 Poorly/Undifferentiated

3 (27%)

34 (57%)

3 (30%)

16 (25%)

Distance from the anal verge

0.731

 ≦5 cm

7 (64%)

28 (53%)

3 (30%)

27 (42%)

  > 5 cm

4 (36%)

32 (47%)

7 (70%)

38 (58%)

Tumor length

0.509

 ≦4 cm

8 (73%)

22 (37%)

3 (30%)

28 (43%)

  > 4 cm

3 (27%)

38 (63%)

7 (70%)

37 (57%)

Circumferential extent

0.480

 ≦50%

4 (36%)

13 (22%)

5 (50%)

22 (34%)

  > 50%

7 (64%)

47 (78%)

5 (50%)

43 (66%)

 Pre-treatment CEA level (mean, ng/mL; 95%CI)

24 (10–38)

28 (19–37)

13 (11–15)

20 (10–30)

0.165

 Post- treatment CEA level (mean, ng/mL; 95%CI)

2 (0.2–4)

6 (4–8)

6 (2–11)

6 (5–7)

0.808

Normalization of post- treatment CEA Level

1.000

 Normal (< 5 ng/mL)

9 (82%)

38 (63%)

6 (60%)

40 (62%)

 Elevated (≧5 ng/mL)

2 (18%)

22 (37%)

4 (40%)

25 (38%)

CEA clearance pattern

0.042

 Exponential decrease (R²≧0.9)

9 (82%)

22 (37%)

8 (80%)

28 (43%)

 Non-exponential decrease (R² < 0.9)

2 (18%)

38 (63%)

2 (20%)

37 (57%)

Concurrent chemotherapy

NA

 Capecitabine

0

0

10 (13%)

65 (87%)

 Infusional fluorouracil

7 (64%)

32 (47%)

0

0

 mFOLFOX6

4 (36%)

28 (53%)

0

0