10534 Background: To evaluate the effect of adjuvant treatment with tamoxifen on the CK-19 mRNA+ circulating tumor cells (CTCs) in patients with early-stage breast cancer. Methods: CTCs were prospectively and longitudinally detected using a specific real-time PCR for CK-19 mRNA in 119 patients with estrogen and/or progesterone receptor-positive tumors during the period of tamoxifen administration. Results: Twenty-two (18.5%) patients had detectable CK-19 mRNA+ CTCs after the completion of adjuvant chemotherapy and in 15 (68.2%) of them adjuvant tamoxifen could not eliminate these cells (persistently positive). In 68 (57.1%) patients no CK-19 mRNA+ CTCs could be detected throughout the follow up period (persistently negative). Seven (46.7%) of the 15 persistently positive and six (8.8%) of the 68 persistently negative patients developed disease recurrence (p=0.00026). Persistence of CK-19 mRNA+ CTCs was associated with a significantly shorter median disease-free interval (p=0.0001) and overall survival (0.0005). Multivariate analysis revealed that the detection of CK-19 mRNA+ CTCs during the administration of tamoxifen was associated with an increased risk of relapse (HR=22.318, p=0.00006) and death (HR=13.954, p< 0.00001). Conclusions: The detection of CK-19 mRNA+ CTCs throughout the period of adjuvant tamoxifen treatment is an independent poor prognostic factor in patients with early breast cancer. No significant financial relationships to disclose.
Adjuvant tamoxifen and exemestane in women with postmenopausal early breast cancer (TEAM): 10-year follow-up of a multicentre, open-label, randomised, phase 3 trial
