Table 3. CTC prevalence and numbers are higher in stage IV CRC patients with lung and extrapulmonary vs. lung only, and liver and extrahepatic vs. liver metastases.
| Total | Lung metastases | Lung and extrapulmonary | P value | Liver metastases | Liver and extrahepatic | P value | |
|---|---|---|---|---|---|---|---|
| n | 90 | 19 (21%) | 22 (24%) | 31 (34%) | 23 (26%) | ||
| CTCs detectable (n) | 36/90 (40%) | 2/19 (11%) | 15/22 (68%) | <0.001a | 10/31 (32%) | 15/23 (65%) | 0.027a |
| CTC number: | |||||||
| Mean (± SEM) | 2.0 (± 0.8) | 0.1 (± 0.1) | 5.9 (± 3.1) | 0.9 (± 0.3) | 5.7 (± 3.0) | ||
| Median (range) | 0 (0–56.3) | 0 (0–1) | 1 (0–56.3) | <0.001b | 0 (0–7) | 1 (0–56.3) | 0.035b |
SEM, standard error of the mean. aFisher exact test; bKruskal–Wallis test.