Table 2.
Multivariable Cox Proportional Hazards Model Analysis for Recurrence-Free Survival for All Patients and for the Patient Subgroup Observed to Be Recurrence-Free at 1 Year and at 2 Years After Colorectal Liver Metastasis Resection
| Variable* | At the time of liver resection (N = 479)† |
1-year recurrence-free (N = 224)‡ |
2-year recurrence-free (N = 109)§ |
||||||
|---|---|---|---|---|---|---|---|---|---|
| Multivariable HR |
95% CI | p Value | Multivariable HR |
95% CI | p Value | Multivariable HR¶ |
95% CI | p Value | |
| T category ≥ 3 | 1.38 | 1.00–1.91 | 0.049 | 1.30 | 0.79–2.16 | 0.30 | – | – | – |
| Extrahepatic disease | 1.46 | 1.12–1.89 | 0.004 | 1.54 | 0.95–2.51 | 0.08 | – | – | – |
| Multiple CLM (vs single) | 1.27 | 1.02–1.57 | 0.029 | 0.96 | 0.68–1.35 | 0.81 | – | – | – |
| Largest CLM diameter > 5 cm | 1.78 | 1.34–2.37 | < 0.001 | 2.79 | 1.63–4.79 | < 0.001 | 2.41 | 0.37–22.19 | 0.40 |
| Surgical margin status, R1 | 1.35 | 1.05–1.73 | 0.021 | 1.00 | 0.60–1.66 | 0.99 | – | – | – |
| RAS/TP53 co-mutation | 1.47 | 1.19–1.82 | < 0.001 | 1.69 | 1.17–2.43 | 0.005 | 2.41 | 1.12–5.17 | 0.024 |
CLM, colorectal liver metastasis; HR, hazard ratio
Based on analysis of data from 468 patients with complete data on T category and lymph node metastasis, 7 variables were selected for the final model as follows: T category (≥ 3 vs. < 3), extrahepatic disease, multiple CLM (vs. single), largest CLM diameter (> 5 cm vs. ≤ 5 cm), surgical margin status (R1 vs. R0), RAS mutation, and TP53 mutation.
Based on analysis of data from 479 patients at the time of liver resection with complete data on T category. Multivariable hazard ratio was calculated with these variables after grouping RAS mutation and TP53 mutation as RAS/TP53 co-mutation.
Based on analysis of data from 224 patients recurrence free at 1 year with complete data on T category. Multivariable hazard ratio was calculated with T category, extrahepatic disease, multiple CLM, largest CLM diameter, surgical margin status, and RAS/TP53 co-mutation.
Based on analysis of data from 109 patients recurrence free at 2 years. Multivariable hazard ratio was calculated with largest CLM diameter and RAS/TP53 co-mutation.
T category, extrahepatic disease, multiple CLM, and surgical margin status were not included in the model because these factors were not associated with risks of recurrence in patients who were recurrence-free at 1 year.