Table 2.
CTC counts and morphologic characteristics in relation to breast cancer subtypea
| Variables | All patients N = 52 |
Hormone receptor positive (ER+, PgR±, HER2-) N = 39 |
HER2 positive (HER2+, ER±, PgR±) N = 7 |
Triple-negative (ER-, PgR-, HER2-) N = 4 |
P-value |
|---|---|---|---|---|---|
| CTC number | |||||
| CTC count at BL median (range) | 45 (5–668) | 44 (5–668) | 111 (12–311) | 88 (39–253) | 0.32 |
| CTC count at 1–3 mo median (range) | 4 (0–263) | 4 (0–263) | 0 (0–9) | 87 (75–144) | 0.007 |
| CTC count at 6 mo median (range) | 1 (0–765) | 1 (0–765) | 0 (0–183) | 2 (2–2) | 0.18 |
| ≥ 5 CTC at 1–3 mo | 0.29 | ||||
| Yes | 19 | 15 | 1 | 3 | |
| No | 29 | 22 | 5 | 1 | |
| Missing | 4 | 2 | 1 | 0 | |
| ≥ 5 CTC at 6 mo | 0.72 | ||||
| Yes | 14 | 12 | 1 | 1 | |
| No | 27 | 19 | 5 | 1 | |
| Missing | 11 | 8 | 1 | 2 | |
| Apoptosis | |||||
| Apoptotic CTC at BL | 0.20 | ||||
| Yes | 40 | 29 | 6 | 4 | |
| Median number (range) | 5 (1–54) | 3 (1–52) | 6.5 (1–54) | 6.5 (5–40) | |
| Median fraction (range) | 0.08 (0.01–0.33) | 0.09 (0.01–0.33) | 0.07 (0.04–0.17) | 0.12 (0.05–0.18) | |
| No | 12 | 10 | 1 | 0 | |
| Missing | 0 | 0 | 0 | 0 | |
| Apoptotic CTC 1–3 mo | 0.17 | ||||
| Yes | 17 | 13 | 1 | 3 | |
| Median number (range) | 3 (1–18) | 3 (1–18) | 2 | 6 (3–9) | |
| Median fraction (range) | 0.13 (0.01–1.0) | 0.13 (0.01–1.0) | 0.22 | 0.04 (0.04–0.10) | |
| No | 31 | 24 | 5 | 0 | |
| Missing | 4 | 2 | 1 | 1 | |
| Apoptotic CTCs 6 mo | 0.49 | ||||
| Yes | 15 | 12 | 1 | 2 | |
| Median number (range) | 2 (1–109) | 2 (1–109) | 2 | 3 (1–5) | |
| Median fraction (range) | 0.09 (0.01–1.0) | 0.11 (0.02–1.0) | 0.01 | 0.29 (0.09–0.50) | |
| No | 26 | 19 | 5 | 0 | |
| Missing | 11 | 8 | 1 | 2 | |
| Clusters | |||||
| Clusters at BL | 0.010 | ||||
| Yes | 9 | 4 | 3 | 2 | |
| Median number (range) | 2 (1–18) | 3 (1–18) | 4 (1–4) | 1.5 (1–2) | |
| Median fraction (range) | 0.02 (0.003–0.03) | 0.02 (0.003–0.03) | 0.01 (0.005–0.02) | 0.02 (0.02–0.03) | |
| No | 43 | 35 | 4 | 2 | |
| Missing | 0 | 0 | 0 | 0 | |
| Clusters at 1–3 mo | 0.026 | ||||
| Yes | 5 | 3 | 0 | 2 | |
| Median number (range) | 1 (1–4) | 1 (1–4) | 1 (1) | ||
| Median fraction (range) | 0.009 (0.006–0.02) | 0.009 (0.006–0.02) | 0.01 (0.007–0.01) | ||
| No | 43 | 34 | 6 | 1 | |
| Missing | 4 | 2 | 1 | 1 | |
| Clusters at 6 mo | 0.98 | ||||
| Yes | 4 | 3 | 1 | 0 | |
| Median number (range) | 6 (1–16) | 10 (2–16) | 1 | ||
| Median fraction (range) | 0.003 (0.001–0.006) | 0.001 (0.001–0.005) | 0.006 | ||
| No | 37 | 28 | 5 | 2 | |
| Missing | 11 | 8 | 1 | 2 | |
| WBC-CTC | |||||
| WBC-CTC at BL | 0.45 | ||||
| Yes | 35 | 26 | 6 | 3 | |
| Median number (range) | 4 (1–38) | 3 (1–38) | 6.5 (1–13) | 4 (2–22) | |
| Median fraction (range) | 0.05 (0.004–0.6) | 0.05 (0.004–0.6) | 0.07 (0.02–0.2) | 0.04 (0.03–0.09) | |
| No | 17 | 13 | 1 | 1 | |
| Missing | 0 | 0 | 0 | 0 | |
| WBC-CTC at 1–3 mo | 0.61 | ||||
| Yes | 12 | 10 | 0 | 2 | |
| Median number (range) | 3.5 (1–101) | 3.5 (1–28) | 51.5 (2–101) | ||
| Median fraction (range) | 0.1 (0.02–1) | 0.1 (0.04–1) | 0.4 (0.02–0.7) | ||
| No | 36 | 27 | 6 | 1 | |
| Missing | 4 | 2 | 1 | 1 | |
| WBC-CTC at 6 mo | 0.49 | ||||
| Yes | 8 | 6 | 1 | 1 | |
| Median number (range) | 6 (1–62) | 5.5 (1–62) | 9 | 3 | |
| Median fraction (range) | 0.05 (0.009–0.09) | 0.04 (0.009–0.09) | 0.05 | 0.05 | |
| No | 33 | 25 | 5 | 1 | |
| Missing | 11 | 8 | 1 | 2 |
WBC-CTC white blood cells associated with CTC, ER estrogen receptor, PgR progesterone receptor, HER2 human epidermal growth factor receptor 2, BL base-line, NHG Nottingham histological grade, MBC metastatic breast cancer, mo months
a Breast cancer subtype was derived from the primary tumor (n = 40) and, if no primary tumor tissue was available, from the metastasis (n = 10). Two patients had insufficient tissue for subtype assessment