Table 1. Baseline characteristics of the population.
| Variables | Total (n=572) |
|---|---|
| Sex, n (%) | |
| Male | 360 (62.9) |
| Female | 212 (37.1) |
| Age (years), median (Q1, Q3); range (min–max) | 62 (56.8, 69.0); (24–94) |
| Charlson Comorbidity Score, median (Q1, Q3); range (min–max) | 10 (9.0, 11.0); (8–16) |
| Presence of co-existing cancers (Hong Kong Top 10), n (%) | |
| No | 557 (97.4) |
| Yes | 15 (2.6) |
| Number of lymph nodes positive in primary CRC, median (Q1, Q3) | 1 (0, 4.0) |
| Colorectal liver metastasis | |
| Pre-treatment PET scan findingsª | |
| Number of tumor nodules, median (Q1, Q3); range (min–max) | 1 (1.0, 3.0); (0–12) |
| Tumor location, n (%) | |
| Unilobar | 343 (70.6) |
| Bilobar | 143 (29.4) |
| Largest tumor diameter (cm), median (Q1, Q3); range (min–max) | 2.5 (1.6, 4.0); (0–16.8) |
| Extrahepatic metastasis, n (%) | |
| No | 423 (89.4) |
| Yes | 50 (10.6) |
| Extrahepatic metastasis site, n (%) | |
| Lung metastasis | 28 (56.0) |
| Bone metastasis | 6 (12.0) |
| Other metastasis | 16 (32.0) |
| Extrahepatic metastasis number, n (%) | |
| Single extrahepatic metastasis | 47 (94.0) |
| Multiple extrahepatic metastases | 3 (7.0) |
| Extrahepatic metastasis resection status, n (%) | |
| Not resected | 28 (56.0) |
| Resected before hepatic resection | 10 (20.0) |
| Resected during hepatic resection | 6 (12.0) |
| Resected after hepatic resection | 6 (12.0) |
| Pre-operative investigations | |
| Albumin (g/L), median (Q1, Q3) | 40.0 (36.0, 43.0) |
| Bilirubin (µmol/L), median (Q1, Q3); range (min–max) | 8.2 (6.0, 12.9); (2.0–51.0) |
| Liver CEA (ng/mL), median (Q1, Q3); range (min–max) | 12.0 (4.6, 45.4); (0.7–4,040.0) |
| Liver pathology report findings | |
| Largest diameter of liver metastasis (cm), median (Q1, Q3); range (min–max) | 3.0 (2.0, 4.0); (0.4–18.0) |
| Number of tumor nodules, median (Q1, Q3); range (min–max) | 2 (1.0,3.0); (0–8) |
| Lymphovascular invasion, n (%) | |
| No | 84 (52.5) |
| Yes | 76 (47.5) |
| Tumor lobar involvement, n (%) | |
| Unilobar | 395 (69.3) |
| Bilobar | 175 (30.7) |
| KRAS, n (%) | |
| No mutation | 250 (58.8) |
| Mutation | 175 (41.2) |
| Treatment received | |
| Neoadjuvant treatment, n (%) | |
| No | 378 (66.7) |
| Yes | 189 (33.3) |
| Adjuvant chemotherapy, n (%) | |
| No | 161 (28.1) |
| Yes | 411 (71.9) |
| Patients who received only neoadjuvant therapy, n (%) | |
| No | 523 (91.6) |
| Yes | 48 (8.4) |
| Patients who received only adjuvant therapy, n (%) | |
| No | 302 (53.2) |
| Yes | 266 (46.8) |
| Patients who received both neoadjuvant and adjuvant chemotherapy, n (%) | |
| No | 427 (75.2) |
| Yes | 141 (24.8) |
| Follow-up | |
| Status, n (%) | |
| Censored (alive at the end of the study or was lost to follow up) | 243 (42.5) |
| Dead | 329 (57.5) |
| RFS, median (Q1, Q3), days | 419.0 (186.5, 1,159.8) |
| OS, median (Q1, Q3), days | 1,169.0 (771.5, 1,893.0) |
| DFI, median (Q1, Q3), days | 0 (0, 218.0) |
This table summarizes patient data on key clinically significant variables only. Additional data on all the 65 variables extracted from patient records is summarized in Table S2. ª, For all patients, data was extracted from their pretreatment/baseline PET scan, where available; for patients who received neoadjuvant chemotherapy, data was extracted from their initial PET scan prior to commencing any neoadjuvant treatment; for the 24 patients who only had PET scan data available after commencing treatment, this was not considered to be representative of their baseline characteristics and thus their PET scan data was not included in analysis. CRC, colorectal cancer; CEA, carcinoembryonic antigen; PET, positron emission-tomography; RFS, recurrence-free survival; OS, overall survival; DFI, disease free interval.