Table 3. Multivariate Cox models of total CK18 (tCK18) and caspase cleaved CK18 (cCK18) prognostic influence on overall survival in patients undergoing first-line conventional chemotherapy for metastatic colorectal cancer (n=55).
| Categories (U l−1) | Hazard ratio (95% CIs) | P continuous | P vs referent | |
|---|---|---|---|---|
| tCK18 model a | ||||
| Continuousb | Per unit log2 | 1.78 (1.37–2.30) | <0.001 | |
| Categorical | ||||
| Tertile 1 (n=18) | 215–370 | 1.00 | ||
| Tertile 2 (n=19) | 371–1189 | 3.48 (1.25–9.70) | 0.017 | |
| Tertile 3 (n=18) | 1190–7098 | 5.42 (2.04–14.3) | 0.001 | |
| cCK18 model a | ||||
| Continuousb | Per unit log2 | 1.93 (1.32–2.81) | 0.001 | |
| Categorical | ||||
| Tertile 1 (n=17) | 64–179 | 1.00 | ||
| Tertile 2 (n=20) | 180–409 | 1.50 (0.62–3.63) | 0.367 | |
| Tertile 3 (n=18) | 410–2388 | 3.18 (1.27–7.94) | 0.013 | |
Abbreviation: CI=confidence interval.
The calibration and performance characteristics for overall survival model for tCK18 were: Harrell’s C-statistic=0.6949 and likelihood ratio for goodness-of-fit=0.867; for cCK18, C=0.6384 and likelihood ratio for goodness-of-fit=3.489.
a
All final models included were adjustment for age, sex, stage, and tCK18 and cCK18, respectively.
b
Interpreted as change in hazard ratio associated with a doubling in CK18 level on the original scale.