Table 1.
Patient characteristics
| Characteristic | Total (n=176) | Synchronous PM (n=54) | Metachronous PM (n=122) | p-value |
|---|---|---|---|---|
| Age (yr) | ||||
| ≤ 60 | 85 (48.3) | 30 (55.6) | 55 (45.1) | 0.25 |
| > 60 | 91 (51.7) | 24 (44.4) | 67 (54.9) | |
| Mean±SD | 60.3±11.7 | 58.3±12.6 | 61.3±11.2 | 0.11 |
| Sex | ||||
| Male | 114 (64.8) | 31 (57.4) | 83 (68.0) | 0.23 |
| Female | 62 (35.2) | 23 (42.6) | 39 (32.0) | |
| Body mass index (kg/m2) | ||||
| ≤ 25 | 131 (74.4) | 43 (79.6) | 88 (72.1) | 0.35 |
| < 25 | 45 (25.6) | 11 (20.4) | 34 (27.9) | |
| Mean±SD | 23.2±3.2 | 22.8±3.4 | 23.4±3.0 | 0.27 |
| Primary tumor location | ||||
| Colon | 78 (44.3) | 23 (42.6) | 55 (45.1) | 0.87 |
| Rectum | 98 (55.7) | 31 (57.4) | 67 (54.9) | |
| Tumor stagea) | ||||
| 1 | 7 (4.0) | 2 (3.7) | 5 (4.1) | < 0.001 |
| 2 | 26 (14.8) | 2 (3.7) | 24 (19.7) | |
| 3 | 86 (48.9) | 14 (25.9) | 72 (59.0) | |
| 4 | 57 (32.4) | 36 (66.7) | 21 (17.2) | |
| Histology of primary tumor | ||||
| Well differentiated | 17 (9.7) | 5 (9.3) | 12 (9.8) | 0.43 |
| Moderately differentiated | 149 (84.7) | 44 (81.5) | 105 (86.1) | |
| Mucinous or poorly differentiated | 10 (5.7) | 5 (9.3) | 5 (4.1) | |
| Previous hepatectomy | ||||
| No | 151 (85.8) | 43 (79.6) | 108 (88.5) | 0.16 |
| Yes | 25 (14.2) | 11 (20.4) | 14 (11.5) | |
| Adjuvant therapy for CRC | ||||
| No | 14 (8.0) | 9 (16.7) | 5 (4.1) | 0.01 |
| Yes | 162 (92.0) | 45 (83.3) | 117 (95.9) | |
| No. of prior regimens | ||||
| 0 | 14 (8.0) | 9 (16.7) | 5 (4.1) | < 0.001 |
| 1 | 125 (71.0) | 41 (75.9) | 84 (68.9) | |
| 2 | 29 (16.5) | 1 (1.9) | 28 (23.0) | |
| 3 | 7 (4.0) | 3 (5.6) | 4 (3.3) | |
| No data | 1 (0.6) | 0 | 1 (0.8) | |
| Prior systemic chemotherapeutic agents | ||||
| 5-FU | 131 (74.4) | 43 (79.6) | 88 (72.1) | - |
| Oxalipatin | 95 (54.0) | 26 (48.1) | 69 (56.5) | |
| Irinotecan | 16 (9.1) | 4 (7.4) | 12 (9.8) | |
| Capecitabine | 56 (31.8) | 14 (25.9) | 42 (34.4) | |
| Bevacizumab | 11 (6.2) | 4 (7.4) | 7 (5.7) | |
| Disease-free interval (mo) | ||||
| < 12 | 75 (42.6) | 54 (100) | 21 (17.2) | < 0.001 |
| ≥ 12 | 101 (57.4) | 0 | 101 (82.8) | |
| Median (range) | 13.0 (0-85) | 0.0 (0-3) | 22.0 (4-85) | |
| No. of pulmonary tumors | ||||
| Solitary | 101 (57.4) | 24 (44.4) | 77 (63.1) | 0.03 |
| Multiple | 75 (42.6) | 30 (55.6) | 45 (36.9) | |
| Median (range) | 1.0 (1-21) | 2.0 (1-21) | 1.0 (1-14) | |
| Maximal tumor size (mm) | ||||
| ≤ 20 | 152 (86.4) | 46 (85.2) | 106 (86.9) | 0.81 |
| > 20 | 24 (13.6) | 8 (14.8) | 16 (13.1) | |
| Median (range) | 12.0 (2-70) | 11.0 (3-60) | 12.0 (2-70) | |
| Distribution of metastases | ||||
| Unilateral | 144 (81.8) | 36 (66.7) | 108 (88.5) | 0.01 |
| Bilateral | 32 (18.2) | 18 (33.3) | 14 (11.5) | |
| Resectionb) | ||||
| Non-anatomical | 132 (75.0) | 42 (77.8) | 90 (73.8) | 0.71 |
| Anatomical | 44 (25.0) | 12 (22.2) | 32 (26.2) | |
| Mediastinal LN dissection | ||||
| No | 106 (60.2) | 36 (66.7) | 70 (57.4) | 0.32 |
| Yes | 70 (39.8) | 18 (33.3) | 52 (42.6) | |
| Mediastinal LN involvement | ||||
| No | 61 (34.7) | 17 (31.5) | 44 (36.1) | 0.36 |
| Yes | 9 (5.1) | 1 (1.9) | 8 (6.6) | |
| No data | 106 (60.2) | 36 (66.7) | 70 (57.4) | |
| Chemotherapy after metastasectomy | ||||
| No | 13 (7.4) | 2 (3.7) | 11 (9.0) | 0.27 |
| Cytotoxic agent only | 139 (79.0) | 42 (77.8) | 97 (79.5) | |
| Cytotoxic agent+targeted agent | 24 (13.6) | 10 (18.5) | 14 (11.5) |
Values are expressed as number (%) unless otherwise indicated. PM, pulmonary metastases; SD, standard deviation; CRC, colorectal cancer; 5-FU, 5-fluorouracil; LN, lymph node.
a)
Using the seventh edition of the American Joint Committee on Cancer staging system,
b)
Non-anatomical resection included precision excision and wedge resection; anatomical resection included segmental resection and lobectomy.