Table 2.
Association of elevated CTC count with metastatic tumor characteristics*
| Characteristic | CTC < 5(n = 54)(56.2%)No. (%) | CTC ≥ 5(n = 42)(43.8%)No. (%) | Total(n = 96) | P |
|---|---|---|---|---|
| ER/PR status† | ||||
| ER/PR+ | 45 (53.6) | 39 (46.4) | 84 | .21‡ |
| ER/PR- | 9 (75.0) | 3 (25.0) | 12 | |
| HER2 status† | ||||
| HER2+ | 9 (60.0) | 6 (40.0) | 15 | .56§ |
| HER2- | 43 (54.4) | 36 (45.6) | 79 | |
| Unknown | 2 (100.0) | 0 (0.0) | 2 | |
| Triple-negative† | ||||
| Yes | 7 (70.0) | 3 (30.0) | 10 | .56§ |
| No | 47 (54.7) | 39 (45.3) | 86 | |
| Line of starting treatment | ||||
| 1 | 20 (58.8) | 14 (41.2) | 34 | .16§ |
| 2 | 14 (56.0) | 11 (44.0) | 25 | |
| ≥3 | 20 (54.1) | 17 (45.9) | 37 | |
| Site of metastases | ||||
| Lung yes | 25 (59.5) | 17 (40.5) | 42 | .67§ |
| Lung no | 29 (53.7) | 25 (46.3) | 54 | |
| Liver yes | 16 (41) | 23 (59) | 39 | .02§ |
| Liver no | 38 (66.7) | 19 (33.3) | 57 | |
| Bone yes | 40 (52.6) | 36 (47.4) | 76 | .20§ |
| Bone no | 14 (70) | 6 (30) | 20 | |
| Brain yes | 2 (33.3) | 4 (66.7) | 6 | .39‡ |
| Brain no | 52 (57.8) | 38 (42.2) | 90 |
*
Percentages in each row add up to 100%. CTC = circulating tumor cell; ER = estrogen receptor; HER2 = human epidermal growth factor receptor 2; PR = progesterone receptor.
†
Current metastatic disease status.
‡
Fisher exact test for analysis of contingency tables, less than five expected counts.
§
Chi-square test for contingency tables.