Association between presence of CTC, disease recurrence
and survival
A total of 54 patients developed disease recurrence during
follow-up. Of the 76 patients with CTC, 16 (21.1%)
developed a recurrence compared to 38 of 328 (11.6%)
patients without CTC (P = 0.029). The four-year RFS is
shown in Figure 1A, patients without CTC had a RFS of
88.4% and for patients with CTC this was 78.9% (logrank
P = 0.038). Time to recurrence ranged from 6 to
90 months. Eleven patients had a recurrence within one
year of inclusion. In accordance with Dutch National
Guidelines a chest X-ray or computed tomography (CT)
scan, ultrasound of the liver and bone scan were performed
in patients with stage III breast cancer prior to
surgery, but not in patients with stage I and II breast
cancer. During follow-up, a total of 34 patients died
from which 25 died of breast cancer-related causes. The
nine patients that died of other causes were not
included in survival analysis, so that only breast cancerrelated
death is analyzed. Eleven of the 25 patients
(40%) who died of breast cancer-related causes had
CTC (44%) in contrast to 65 of the 328 patients (20%)
with no CTC (log-rank P = 0.001). BRD is shown in Figure
1B. Of the patients without CTC, 4.3% died due to
breast cancer-related causes. In the group of patients
with CTC this was 14.5% (log-rank P = 0.001). Time till
death ranged from 6 to 89 months. All 25 patients who
died were also included in the recurrence group.