Table 5.
Multivariate regression analysis with tumor downstaging as dependent variable
| Variable | Good downstaging | Poor downstaging | P | Odds Ratio (95%CI) |
|---|---|---|---|---|
| Training cohort | ||||
| Pretreatment T stage | 0.04 | 10.14 (1.11–92.55) | ||
| T2–3 | 19 (95%) | 33 (65%) | ||
| T4 | 1 (5%) | 18 (35) | ||
| Tumor differentiation | 0.032 | 4.21 (1.13–15.68) | ||
| Well/Moderately | 14 (70%) | 20 (40%) | ||
| Poorly/Undifferentiated | 6 (30%) | 31 (60%) | ||
| CEA clearance pattern | 0.002 | 8.25 (2.19–31.10) | ||
| Exponential decrease (R2≧0.9) | 15 (75%) | 16 (31%) | ||
| Non-exponential decrease (R2 < 0.9) | 5 (25%) | 35 (69%) | ||
| Validation cohort | ||||
| Pretreatment T stage | 0.108 | 0.31 (0.08–1.29) | ||
| T2–3 | 26 (78%) | 42 (86%) | ||
| T4 | 0 | 7 (14%) | ||
| Tumor differentiation | 0.752 | 1.22 (0.36–4.09) | ||
| Well/Moderately | 19 (73%) | 37 (76%) | ||
| Poorly/Undifferentiated | 7 (27%) | 12 (24%) | ||
| CEA clearance pattern | 0.008 | 4.28 (1.47–12.43) | ||
| Exponential decrease (R2≧0.9) | 18 (69%) | 18 (37%) | ||
| Non-exponential decrease (R2 < 0.9) | 8 (31%) | 31 (63%) | ||
The p value in boldface means statistically significant, that is, less than 0.05